@article { ISI:000295259700041, title = {N-Heterocyclic carbene catalyzed umpolung of michael acceptors for intermolecular reactions}, journal = {Angewandte Chemie-International Edition}, volume = {50}, number = {36}, year = {2011}, month = {AUG}, pages = {8412-8415}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

eahciM! The N-heterocyclic carbene catalyzed umpolung of Michael acceptors proceeds through the formation of a deoxy-Breslow intermediate (see scheme; EWG=electron-withdrawing group). This nucleophilic species can react with other Michael acceptors in an intermolecular fashion, thereby resulting in the formation of homo- or heterodimeric olefins. This {\textquotedblleft}Michael umpolung{\textquotedblright} should become a valuable method for the formation of densely functionalized olefins.

}, keywords = {carbenes, Michael acceptors, nitrogen heterocycles, organocatalysis, umpolung}, issn = {1433-7851}, doi = {10.1002/anie.201103555}, author = {Biju, Akkattu T. and Padmanaban, Mohan and Wurz, Nathalie E. and Glorius, Frank} } @article { ISI:000339493400008, title = {General approach to N-heterocyclic carbenes with a fused tetracyclic core: ligands for suzuki-miyaura cross-coupling reaction}, journal = {European Journal of Organic Chemistry}, number = {21}, year = {2014}, month = {JUL}, pages = {4482-4486}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading.

}, keywords = {C-C coupling, carbenes, Homogeneous catalysis, N ligands, synthetic methods}, issn = {1434-193X}, doi = {10.1002/ejoc.201402378}, author = {Sutar, Revannath L. and Kumar, Vinod and Shingare, Rahul D. and Thorat, Shridhar and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article { ISI:000370029900002, title = {Compounds with low-valent p-block elements for small molecule activation and catalysis}, journal = {Chemcatchem}, volume = {8}, number = {3}, year = {2016}, month = {FEB}, pages = {486-501}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

The past decade has witnessed staggering progress in the chemistry of compounds with low-valent main-group elements. Although these discoveries are mostly fundamental by nature, these compounds show promising reactivity towards small molecule activation. The reactivity of these compounds stems from the modest HOMO-LUMO energy gap; a characteristic known for the transition metals. The journey began in 2005 with the facile activation of dihydrogen by an alkyne analog of germanium [ArGeGeAr; Ar=2,6-Trip(2)-C6H3 (Trip=2,4,6-iPr(3)-C6H2)]. Subsequently, tremendous progress has been achieved in understanding and elucidating the potential of these compounds to activate small molecules as well as to use them in a variety of stoichiometric and catalytic transformations. In this review, we focus on developments in the activation of H-2, NH3, CO, and CO2 by compounds with multiply bound or open shell main-group elements. Emphasis will be given to their catalytic activity.

}, keywords = {activation, carbenes, main-group elements, silylenes, small molecules}, issn = {1867-3880}, doi = {10.1002/cctc.201501015}, author = {Yadav, Sandeep and Saha, Sumana and Sen, Sakya S.} }