Atanu Modak

Site-selective C-H functionalization has emerged as an efficient tool in simplifying the synthesis of complex molecules. Most often, directing group (DG)-assisted metallacycle formation serves as an efficient strategy to ensure promising regioselectivity. A wide variety of ortho- and meta-C-H functionalizations stand as examples in this regard. Yet despite this significant progress, DG-assisted selective para-C-H functionalization in arenes has remained unexplored, mainly because it involves the formation of a geometrically constrained metallacyclic transition state. Here we report an easily recyclable, novel Si-containing biphenyl-based template that directs efficient functionalization of the distal p-C-H bond of toluene by forming a D-shaped assembly. This DG allows the required flexibility to support the formation of an oversized pre-transition state. By overcoming electronic and steric bias, para-olefination and acetoxylation were successfully performed while undermining o- and m-C-H activation. The applicability of this D-shaped biphenyl template-based strategy is demonstrated by synthesizing various complex molecules.

An economical approach to α-CF3-substituted ketones, which are important intermediates in synthetic and medicinal chemistry, employs olefins and the readily available Langlois reagent (CF3SO2Na). The reaction is operationally simple, proceeds at room temperature, and exhibits an excellent tolerance toward a wide variety of functional groups. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Various practical methods for the selective C-H functionalization of the ortho and recently also of the meta position of an arene have already been developed. Following our recent development of the directing-group-assisted para C-H functionalization of toluene derivatives, we herein report the first remote para C-H functionalization of phenol derivatives by using a recyclable silicon-containing biphenyl-based template. The effectiveness of this strategy was illustrated with different synthetic elaborations and by the synthesis of various phenol-based natural products.

A nitrile-based template attached with a phenylacetic acid framework promoted meta-selective C-H bond olefination. This palladium-catalyzed protocol is applicable to a wide range of substituted phenylacetic acids and tolerates a variety of functional groups. The versatility of this operationally simple method has been demonstrated through drug diversification.

A facile decarbonylation reaction of aldehydes has been developed by employing Pd(OAc)2. A wide variety of substrates are decarbonylated, without using any exogenous ligand for palladium as well as CO-scavenger.

A direct and versatile copper-catalyzed trifluoromethylthiolation and trifluoromethylselenation of primary, secondary, and tertiary aliphatic C–H bonds was developed. The reaction provides direct access to molecules containing these emerging moieties in the presence of a wide range of common functional groups and in complex molecular environments.

An intramolecular dehydrogenative (sp3)C–O bond formation in salicylamides can be initiated by an active Cu/O2 species to generate pharamaceutically relevant dihydro-oxazinones. Experimental findings suggest that stereoelectronic parameters in both coupling partners are controlling factors for site selectivity in bond formation. Mechanistic investigations including isotope labeling, kinetic studies helped to propose a catalytic cycle. The method provides a convenient synthesis of an investigational new medicine CX-614, which has potential in finding treatment for Parkinson’s and Alzheimer’s diseases.

Strong σ-coordination by a heteroatom containing directing group (DG) is one of the effective strategies for performing site-selective C–H functionalization. Despite tremendous progress in directed ortho-C–H functionalization, selective meta-C–H functionalization using strong σ-coordination remains extremely challenging. Herein, we introduce the 8-nitroquinoline-based DG to ensure the formation of a stable palladacycle which enables selective meta-alkenylation and acetoxylation of arenes. Kinetic experiments, ESI-MS, NMR, and DFT studies provided important information regarding the mechanism of the reaction. The scalability as well as diversification of the products have been examined and are expected to be beneficial in pharmaceutical and material sciences.

Defunctionalization has a direct impact on the synthesis of value added products (e.g. biomass degradation). In synthetic chemistry it enables the functional group to act as a transient directing group. In this mini review, we have described the chronological development of metal assisted defunctionalization reactions from the stoichiometric to the catalytic stage with their application in synthetic organic chemistry. The proposed catalytic cycles of the transformations have been described to make this review comprehensible.

Selective meta-C–H activation of arenes to date has met with a limited number of functionalizations. Expanding the horizon of meta-C–H functionalization, herein we disclose an unprecedented meta-silylation and -germanylation protocol by employing a simple nitrile-based directing template. Longer linkers between the target site and the directing template were successfully explored for meta-silylation (sp2-ε and sp2-ζ). Additionally, synthetic utility was demonstrated with several postsynthetic elaborations and with a formal synthesis of TAC101, a promising drug for the treatment of lung cancer.

Ein ökonomischer Zugang zu α-CF3-substituierten Ketonen, die wichtige Intermediate der synthetischen und medizinischen Chemie sind, nutzt Olefine und das leicht zugängliche Langlois-Reagens (CF3SO2Na). Die Reaktion ist operativ einfach, verläuft bei Raumtemperatur und ist mit vielen funktionellen Gruppen kompatibel. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A number of pharmaceutical compounds possess an arylated 2-pyridone moiety. The existing reports using expensive starting materials and/or superstoichiometric metal salts have prompted us to explore a possible user-friendly method for their synthesis. In this report, we demonstrate an easy-to-handle reaction condition with an iron catalyst for the exclusive generation of C-3-arylated pyridone via C–H functionalization.

This discovery illustrates selective meta C-H bond activation from multiple non-equivalent C-H bonds present in medicinally relevant arylethanesulfonic acid and the 2-arylpropanoic acid moiety using weakly coordinating nitrile as a directing group. Transformation of the meta olefinated compounds to important organic molecules has been demonstrated. Efforts were made to obtain mechanistic detail of the meta C-H bond functionalization reaction.

Sparse polynomial chaos expansion (PCE) combined with the bootstrap resampling method is a viable alternative to obtain an active learning algorithm for reliability analysis. The existing learning functions in PCE-based active learning algorithms do not consider the joint probability density function (PDF) information. The present study explores a sparse PCE-based active learning algorithm based on a newly proposed learning function that maintains a balance between the misclassification probability and the joint PDF of sample points. In doing so, the coefficients of the sparse PCE are estimated using a Bayesian compressive sensing regressor, as it is noted to be one of the best-performing regression solvers for PCE, irrespective of sampling schemes. The proposed learning function considers the weight of the joint PDF with the local accuracy measure of bootstrap PCE (bPCE) to add new samples iteratively in the existing training set. The convergence is achieved when the ten consecutive failure estimates are within a negligible discrepancy and also checks the confidence bounds of the bPCE estimates. The effectiveness of the proposed approach is demonstrated using two structural engineering examples and one well-known analytical test function and is found to be quite efficient and accurate in estimating reliability.

Abstract A practical and convenient decarbonylation of a variety of aromatic, heteroaromatic, and alkenyl aldehydes by using palladium nanoparticles supported on novel, fibrous nanosilica, named KCC‐1‐PEI/Pd, has been developed. Complete conversion of aldehyde functionalities into deformylated products was achieved in all cases and in nearly all cycles tested by reusing the catalyst systems. This method eliminates further purification of products after their isolation. Syntheses of at least three different deformylated products have been shown in sequence with the same catalyst system, which neither requires use of any additives, such as oxidants and bases, nor CO scavengers.

Abstract Various practical methods for the selective C−H functionalization of the ortho and recently also of the meta position of an arene have already been developed. Following our recent development of the directing‐group‐assisted para C−H functionalization of toluene derivatives, we herein report the first remote para C−H functionalization of phenol derivatives by using a recyclable silicon‐containing biphenyl‐based template. The effectiveness of this strategy was illustrated with different synthetic elaborations and by the synthesis of various phenol‐based natural products.

Copper, an earth-abundant metal, has reemerged as a viable alternative to the versatile Pd-catalyzed C-N coupling. Coupling sterically hindered reaction partners, however, remains challenging. Herein, we disclose the discovery and development of a pyrrole-ol ligand to facilitate the coupling of ortho-substituted aryl iodides with sterically hindered amines. The ligand was discovered through a library screening approach and highlights the value of mining heteroatom-rich pharmaceutical libraries for useful ligand motifs. Further evaluation revealed that this ligand is uniquely effective in these challenging transformations. The reaction enables the coupling of sterically hindered primary and secondary amines, anilines, and amides with broad functional group tolerance.

Selective hydrogenolysis of C-CN bonds can allow chemists to take advantage of ortho-directing ability, α-C-H acidity and electron withdrawing ability of the cyano group for synthetic manipulations. We have discovered hydrogenolysis of aryl and aliphatic cyanides under just 1 bar of hydrogen by using a nickel catalyst. This protocol was applied in the aryl cyanide directed functionalization reaction and α-substitution of benzyl cyanides.

A general method for selective dehydroxymethylation has been discovered by using widely available Pd(OAc)(2). The present study offers a new synthetic strategy for the regioselective functionalization by employing the steric, electronic and coordinating nature of the hydroxymethyl (-CH(2)OH) group temporarily.

The ability to manipulate C-C bonds for selective chemical transformations is challenging and represents a growing area of research. Here, we report a formal insertion of diazo compounds into the "unactivated" C-C bond of benzyl bromide derivatives catalyzed by a simple Lewis acid. The homologation reaction proceeds via the intermediacy of a phenonium ion, and the products contain benzylic quaternary centers and an alkyl bromide amenable to further derivatization. Computational analysis provides critical insight into the reaction mechanism, in particular the key selectivity-determining step.

Substoichiometric iron mediates the thioetherification of unactivated aliphatic C–H bonds directed by resident silylperoxides. Upon exposure to a catalytic amount of iron(II) triflate, TIPS-protected peroxides bearing primary, secondary, and tertiary C–H sites undergo chemoselective thioetherification of remote C–H bonds with diaryl disulfides. The reaction demonstrates a broad substrate scope and functional group tolerance without the use of any noble metal additives. Mechanistic experiments suggest that the reaction proceeds through 1,5-H atom abstraction by a hydroxyl radical generated with iron.

Herein, we describe a formal dehydrogenative cross coupling of heterocycles with unactivated aliphatic amines. The resulting transformation enables the direct alkylation of common heterocycles by merging N-F-directed 1,5-HAT with Minisci chemistry, leading to predictable site selectivity. The reaction provides a direct route for the transformation of simple alkyl amines to value-added products under mild reaction conditions, making this an attractive option for C(sp3)-H heteroarylation.

A facile, efficient, and general deformylation reaction with a wide‐ranging functional group compatibility has been developed with palladium acetate as a precatalyst under exogenous ligand‐free conditions. The mechanistic details of the palladium‐catalyzed deformylation reaction have been outlined on the basis of a combination of experimental and computational studies. The heterogeneous pathway is predominant for the deformylation, and homogeneous catalysis occurs to a lesser extent. This ligand‐free catalytic cycle is proposed to undergo oxidative addition, migratory extrusion, and reductive elimination as the key steps. Kinetic studies reveal a first‐order rate dependency with respect to the aldehyde. Furthermore, kinetic isotope effects, competition experiments, and Hammett studies suggest that the migratory extrusion step is the rate‐determining step. For the homogeneous pathway, the experimental findings are also supported by DFT studies.

Abstract Process of through-air-drying is becoming increasingly popular in the manufacture of textiles, non-wovens, tissue, and towel. Very high drying rates, enhanced product properties, i.e., softness, bulk, absorbency, unique 3D structure are the driving forces behind its increasing popularity. In this article, experimental results on convective heat and mass transfer and fluid flow characteristics of tissue and towel products using commercially realistic structures are presented. Comparison with literature data using wet pressed, dried, rewetted sheets indicate significant differences in drying and permeability characteristics confirming that the internal structure of the material does indeed play a significant role in through-air-drying and should be taken into account in modeling, optimization, and control of commercial systems. Keywords: Convective heat transferMass transferThrough-air dryingTissueTowelExperimentalTheoretical

The extension of the Darcy law (the Forchheimer flow equation) relating second-order nonlinear pressure drop with flow velocity is studied during fast transient through air drying of sheets of porous biobased materials such as paper. A range of the paper materials with open structure consistent with tissue and towel products (basis weights 25 and 50 g/m2) made using different production processes are analyzed for the factor-specific influences with regard to changes in the fluid resistance from the removal of moisture from the material interstices. A characteristic dimension suitable for the drying process is applied from viscous and inertial momentum transport analysis.

During the last few decades, transition metal catalysts, especially those on precious metals have proven to be efficient for a large number of applications. Due to its abundance, inexpensiveness, and environmentally benign nature, use of iron has increased significantly in the last two decades for synthetic transformation both in asymmetric synthesis and reaction methodology. This development encouraged to summarize the use of iron catalysis in organic synthesis, which includes cycloadditions, CC, CN bond formation, redox, and other reactions. Trifluoromethylated cyclopropanes are important compounds in drug delivery, though very few synthetic methods were reported for their preparation. This chapter has been divided into different sections based on the reaction type. It discusses that the iron-catalyzed cross-coupling reaction mechanism is versatile and varies with the nature of the coupling partners and based on the reaction condition. Sulfoxides are an important class of compounds since they were used for various ligand syntheses.

The realm of transition metal-catalyzed direct arylation via C–H activation has undergone significant advances in recent years. It has been established as a viable alternative to the standard cross-coupling reaction with organometallic reagents. The use of directing moieties, often through coordination to the catalytic metal, enhances the reactivity and regioselectivity of the C–H activation. In this chapter, the contribution of transition metals such as palladium, rhodium, ruthenium, iridium and copper is discussed. Mechanistic aspects, including the roles of the potential directing groups and of other additives, are emphasized. This chapter serves a concise summary along with essential information that could be beneficial for further understanding and development.

Abstract The mass spectral fragmentation of substituted tetrahydro‐1,3,2‐oxazaphosphorin‐2‐oxides occurs by the cleavage of ring bonds. The ions due to simple cleavage, single and double hydrogen migration, seem to be triggered by CO bond cleavage of the oxazaphosphorin ring. The variations in the relative abundance of ions arising due to similar fragmentation modes have been found to depend on the nature of the substituent and the stability of the particular fragment. The single hydrogen transfer process is supported by metastable ion and shift techniques.

In this study experimental results and analysis are given of convective heat and mass transfer in the drying of tissue and towel products (25 and 50 g/m2 basis weight) under commercially realistic conditions under through flow. Parameter effects on drying rate include process variables such as refining, shaping, commercial forming, initial moisture content, and drying temperature. Drying rate curves display initial increase, plateau, and final decrease as the paper dries. Nondimensional Sherwood numbers (versus Peclet number) generally agreed with and augment the available dataset on through drying.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Sudeep Bhattacharjee, Manoj K. Harbola, Avradip Pradhan, Atanu Modak; Coexistence of tunneling and displacement currents in a nanogap driven with ac fields. Appl. Phys. Lett. 9 April 2012; 100 (15): 153104. https://doi.org/10.1063/1.3702454 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioApplied Physics Letters Search Advanced Search |Citation Search

Through-air drying is commonly used in the drying of high-quality tissue and towel products. A representative elementary volume method was used to model the fluid flow and heat and mass transfer during through drying in heterogeneous porous biobased materials such as tissue and towel products. Results of flow both upstream and downstream of a modeled porous sheet allowed visualization of the effects of mixing at the top and bottom of the porous medium. The effect of initial nonuniformity on fluid flow and convective heat and mass transfer in heterogeneous porous media was studied. The effect of material nonhomogeneity and associated transport properties on moisture content of the porous material as a function of drying time was studied. Modeling results indicate that for the first time it is possible to simulate the effect of nonuniformity on fluid flow and convective heat and mass transfer in porous media during through-air drying of paper. Moisture and structural nonuniformity contributing to nonuniformity in air flow might contribute significantly to drying nonuniformity. Depending on the moisture regimes and degree of saturation of the convective medium, heat and mass transfer coefficients may have varying effects on the overall drying.

We report the dual-catalytic enantioselective allylic alkylation of 2-(pyridylmethyl)amine-derived ketimines with allylic carbonates. The reaction proceeds under mild reaction conditions to generate α-amino heteroaryl benzylamine stereocenters in good yield and enantioselectivity. Enantioselectivity is achieved through the use of a copper catalyst modified with chiral bisphosphine ligand (2S,4S)-bis(diphenylphosphino)pentane.

A Real-Time demonstrator based on the ATCA Pulsar-IIB custom board and on the Pattern Recognition Mezzanine (PRM) board has been developed as a flexible platform to test and characterize low-latency algorithms for track reconstruction and L1 Trigger generation in future High Energy Physics experiments.The demonstrator has been extensively used to test and characterize the Track-Trigger algorithms and architecture based on the use of the Associative Memory ASICs and of the PRM cards.The flexibility of the demonstrator makes it suitable to explore other solutions fully based on a high-performance FPGA device.

Transition metal-catalyzed decarbonylation is an essential paradigm of synthetic organic chemistry. Decarbonylation offers a unique pathway to decoding the skeletal structure of arenes and enabling easy synthesis of structurally complicated molecules. Due to the omnipresence of carbonyl groups in a wide array of synthetically important complex molecules, the variety and scope of these transformations are enormous. As a result, the development of transition metal catalysts in such a simple decarbonylation reaction ranks among one of the most important topics in synthetic organic chemistry. Transition metals that have been employed range from 3d metals like V to second-row transition metals like Pd. The growing potential of this methodology has driven the pioneers of synthetic organic chemistry into delving into the details of this transition metal-catalyzed decarbonylation pathways. This review aims to take the readers through the employment of transition metals in various decarbonylation processes developed by our group, sticking not only to the scope and diversification of synthetically complex molecules, but also enabling the readers to understand the mechanistic insights, through computational and kinetic studies put forward in such reaction protocol, hoping to pave the way for future organic chemists to delve and hopefully solve the unique problems associated with this protocol.

Among the most essential crops for human consumption is rice, and leaf diseases can significantly affect yield and quality. Almost half of the world’s population eats this cereal grain. The identification of rice leaf diseases is crucial for the economy and food security. Rapid corrective measures could be anticipated by understanding the disorders through their peculiar characteristics. The majority of the technical issues with image recognition and classification have been solved using deep learning-based CNN techniques. This study aims to identify the optimal Convolutional Neural Network (CNN) architecture for detecting diseases on rice leaves, considering accuracy, recall, and precision as evaluation metrics. By accurately identifying diseases, the proposed procedure provides valuable assistance to farmers in ensuring healthy crop production. Our analysis reveals that the proposed convolutional model achieves a 75% accuracy rate, demonstrating its effectiveness in disease detection. The suggested method’s validity is supported by experimental results, and it effectively identifies rice diseases.

Current certification systems suffer from various problems such as vulnerability to fraud, time-consuming verification processes, delays in obtaining certificates, limited access due to geographical limitations, high costs, outdated content, lack of flexibility, credibility concerns, quality control issues, technical difficulties, limited interaction, limited feedback, and barriers to access. To address these problems, we propose a solution in the form of Certifier Dapp, a decentralized application built on the Ethereum blockchain. The Certifier Dapp leverages the MetaMask wallet for authentication and communication with the blockchain and offers functionalities such as issuing new certificates, updating issued certificates, verifying certificates, and tracking change history. Utilizing blockchain technology, the Certifier Dapp ensures data integrity, immutability, transparency, and security. The proposed solution aims to provide a seamless and efficient certification process, overcoming the limitations of current certification systems and making certification more accessible and credible for users.

Abstract Nonuniformities in porous materials can play a significant role in the convective and diffusive transport of fluid, heat, and mass. This study provides experimental results and corresponding numerical simulation results. The experiments report continuous data in transient test runs with measurements of temperature and velocity at distributed locations in the domain immediately downstream of the porous materials. An increasing degree of nonuniformity was found to produce a lower drying rate as well as an earlier onset of falling rate drying. The numerical model provides results of the effects of different nonhomogeneities such as distributed holes or distributed regions of varying permeability and moisture content. Comparisons between numerical and experimental test results indicate general agreement with differences with regard to details of the drying curve features. This provides a tool for studying the role of nonuniformity in fluid flow and heat and mass transfer in porous media. Keywords: CFDConvectionHeat and mass transferNonuniformityPaper drying ACKNOWLEDGMENTS The authors express their sincere gratitude to Professor Terrence Simon from the Department of Mechanical Engineering, University of Minnesota, and Dr. G. Worry of Georgia Pacific Corporation for research project support and funding. We also acknowledge the Minnesota Supercomputer Institute (MSI) at the University of Minnesota for making available the supercomputing resources and FLUENT/ANSYS Inc.

Abstract The mass spectral fragmentation modes of various 2‐chloro‐3,6‐diaryl‐3,4‐dihydro‐1,3,2‐oxazaphosphorin‐2‐oxides—a novel ring system—reveal cycloreversion by two pathways. Retro Diels‐Alder reaction by a stepwise mechanism is prominent in this system. The relative abundances of the enone and dienophile ions depend on the nature of the substituent attached to the double bond in this ring. Another retro Diels‐Alder fragmentation process, involving the loss of PO 2 Cl from the molecular ion, is preceded by a 1,3‐allylic rearrangement and is the major fragmentation mode in the metastable time scale. Further fragmentation of the [MPO 2 Cl] + imine ion seems to occur from cyclic dihydroquinoline intermediates by substitution elimination steps.

Abstract Review: 174 refs.

Abstract Phenylacetic acids (I) and (V) having a 2‐hydroxybenzonitrile substituent as directing group undergo meta‐selective olefination with acrylates and vinyl ketones.

Abstract The oxidative Cu‐catalyzed cyclization of salicylamides having two N‐alkyl substituents is developed to give dehydrooxazine derivatives in good yields.

Abstract An efficient and general method to access α‐CF 3 ‐substituted ketones is developed.

Abstract Review: 157 refs.

Abstract The directing‐group‐assisted para C—H functionalization of toluene derivatives occurs under assistance of a recyclable silicon‐containing biphenyl‐based template.

Abstract C‐3‐arylated 2‐pyridones are synthesized by direct C‐H coupling of the corresponding N‐alkyl‐2‐pyridones with arylboronic acids using potassium peroxodisulfate as oxidant in the presence of Fe(III)‐catalyst.

Related Article: T.K.Sen, A.Mukherjee, A.Modak, P.K.Ghorai, D.Kratzert, M.Granitzka, D.Stalke, S.K.Mandal|2012|Chem.-Eur.J.|18|54|doi:10.1002/chem.201103224

Abstract The title reaction tolerates a variety of substrates, allowing the dehydroxymethylation of aryl‐ and hetaryl compounds (I), as well as the extension of this protocol to aliphatic moieties (III).

ChemInformVolume 45, Issue 2 Isocyclic Compounds ChemInform Abstract: Nickel-Catalyzed Hydrogenolysis of Unactivated Carbon—Cyano Bonds. Tuhin Patra, Tuhin Patra Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this authorSoumitra Agasti, Soumitra Agasti Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this authorAtanu Modak, Atanu Modak Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this authorDebabrata Maiti, Debabrata Maiti Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this author Tuhin Patra, Tuhin Patra Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this authorSoumitra Agasti, Soumitra Agasti Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this authorAtanu Modak, Atanu Modak Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this authorDebabrata Maiti, Debabrata Maiti Dep. Chem., IIT Bombay, Powai, Mumbai 400 076, IndiaSearch for more papers by this author First published: 19 December 2013 https://doi.org/10.1002/chin.201402055Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume45, Issue2January 14, 2014 RelatedInformation

Abstract A wide range of substrates are decarbonylated, without the need for an exogenous ligand for palladium as well as CO‐scavenger.

The increase of the luminosity in the High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) will require the use of Tracker information in the evaluation of the Level-1 trigger in order to keep the trigger rate acceptable (i.e.: <;1MHz). In order to extract the track information within the latency constraints (<;5μs), a custom real-time system is necessary. We developed a prototype of the main building block of this system, the Pattern Recognition Mezzanine (PRM) that combines custom Associative Memory ASICs with modern FPGA devices. The architecture, functionality and test results of the PRM are described in the present work.

Correction for 'Remote meta C-H bond functionalization of 2-phenethylsulphonic acid and 3-phenylpropanoic acid derivatives' by Atanu Modak et al., Chem. Commun., 2016, 52, 13916-13919.

The CMS Phase-1 pixel detector was designed to cope with an instantaneous luminosity of 2×10 34 cm -2 s -1 at 25 ns bunch spacing with very small efficiency loss.The Phase-1 pixel detector features four barrel layers and three disks per side, with in total 124 Million pixels, while the original CMS pixel detector had one layer and disk less in the barrel and endcap respectively, and only half the number of channels.DC-DC converters were introduced to deliver more power to the detector without the need of replacing the cable plant.CO 2 based cooling was implemented and carbon-based structures were constructed to reduce the material in the tracking volume.The data acquisition system was upgraded to accept higher event rates and a new, digital data format from the detector front-ends.The detector was installed in early 2017 and has been successfully operated since.The LHC is going through a planned long shutdown period during 2019-2020.The pixel detector was extracted in early 2019 after the end of Run 2 data taking and has been kept cold to protect the silicon sensors.The innermost barrel layer will be replaced during this shutdown period and will feature improved ASICs and circuit boards to rectify issues discovered during data taking.This paper focuses on the operational experience of the detector in 2018, highlighting the detector performance and addressing the lessons learned.The current status of the detector and the refurbishment plan will also be discussed.

Abstract The chemical ionization mass spectra of some substituted heterocyclic systems, viz. tetrahydro‐1,3,2‐oxazaphosphorin‐2‐oxides, reveal polar cycloreversion reactions. The zwitterion intermediate formed by the heterolysis of the CO bond undergoes stepwise clean heterolysis further resulting in the expulsion of the potential nucleophilic and electrophilic groups. The competitive and consecutive heterolysis of the ring bonds leads to the formation of the protonated phenylimine ions. Competing with heterolysis, elimination reactions involving hydrogen transfer leading to the formation of α‐phenylethyl ions are also observed. The chemical ionization mass spectrometry of the heterocyclic system shows many features of the Grob type of fragmentation mechanism.

Abstract Die β‐Aminoketone (Ia)‐(ld) werden mit POCI, zu den Chlor‐oxazaphosphorinoxiden (IIa)‐(IId) cyclisiert.

Abstract Die Arylamino‐propanole (I), (IV) und (VI) werden mit POCI; zu den Chlor‐oxazaphosphorinoxiden (II), (V) bzw. (VII) cyclisiert.

The title salt, [(C 2 H 5 ) 3 NH] + .C 4 H 9 F 2 NO 5 PS - , was the unexpected product in an attempted synthesis of [(CH 3 ) 2 CHO] 2 P(O)CF 2 SO 2 NH 2 from [(CH 3 ) 2 CHO] 2 P(O)CF 2 Br and hydroxylamine-O-sulfonic acid. Both the S and P atoms are surrounded tetrahedrally, with the O-S-O and O-P-O bond angles of 120.7 (2) and 121.4 (1)°, respectively, showing the greatest distortion from true tetrahedral geometry. The remaining bond distances and angles have typical values, with the bond distances to C(1), the fluorinated C atom, being slightly longer.

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInformVolume 20, Issue 23 Organoelement Compounds ChemInform Abstract: Synthesis of (Sulfodifluoromethyl)phosphonic Acid D. J. BURTON, D. J. BURTON Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorA. S. MODAK, A. S. MODAK Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorR. GUNERATNE, R. GUNERATNE Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorD. SU, D. SU Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorW. CEN, W. CEN Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorR. L. KIRCHMEIER, R. L. KIRCHMEIER Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorJ. M. SHREEVE, J. M. SHREEVE Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this author D. J. BURTON, D. J. BURTON Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorA. S. MODAK, A. S. MODAK Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorR. GUNERATNE, R. GUNERATNE Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorD. SU, D. SU Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorW. CEN, W. CEN Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorR. L. KIRCHMEIER, R. L. KIRCHMEIER Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this authorJ. M. SHREEVE, J. M. SHREEVE Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USASearch for more papers by this author First published: June 6, 1989 https://doi.org/10.1002/chin.198923224Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume20, Issue23June 6, 1989 RelatedInformation