@article { ISI:000228412500017, title = {Structural rationalisation of co-crystals formed between trithiocyanuric acid and molecules containing hydrogen bonding functionality}, journal = {Chemistry - A European Journal}, volume = {11}, number = {8}, year = {2005}, note = {Symposium on Chemistry-A European Conference - Stimulating Concepts in Chemistry, Inst Sci Ingenierie Supramoleculaires, Strasbourg, FRANCE, APR 15, 2005}, month = {APR}, pages = {2433-2439}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

Crystallisation of trithiocyanuric acid (TTCA) from various organic solvents that have hydrogen bonding capability (acetone, 2-butanone, dimethylformamide, dimethyl sulfoxide, methanol and acetonitrile) leads to the formation of co-crystals in which the solvent molecules are incorporated together with TTCA in the crystal structure. Structure determination by single-crystal X-ray diffraction reveals that these co-crystals can be classified into different groups depending upon the topological arrangement of the TTCA molecules in the crystal structure. Thus, three different types of single-tape arrangements of TTCA molecules and one type of double-tape arrangement of TTCA molecules are identified. In all co-crystals, hydrogen-bonding interactions are formed through the involvement of N-H bonds of TTCA molecules in these tapes and the other molecule in the co-crystal. Detailed rationalisation of the structural properties of these co-crystals is presented.

}, keywords = {crystal engineering, hydrogen bonds, nitrogen heterocycles, structure elucidation}, issn = {0947-6539}, doi = {10.1002/chem.200400340}, author = {Ahn, Sung-Hoon and PrakashaReddy, J. and Kariuki, B. M. and Chatterjee, S. and Ranganathan, A. and Pedireddi, V. R. and Rao, C. N. R. and Harris, Kenneth D. M.} } @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:000309597000010, title = {Ruthenium-catalyzed C6-propenylation reactions of substituted pyridine derivatives: directed and direct C-H activation}, journal = {Chemistry-A European Journal}, volume = {18}, number = {42}, year = {2012}, month = {OCT}, pages = {13288-13292}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, keywords = {alkenylation, C?H activation, nitrogen heterocycles, pyridine derivatives, ruthenium}, issn = {0947-6539}, doi = {10.1002/chem.201202379}, author = {Goriya, Yogesh and Ramana, Chepuri V.} } @article { ISI:000380138100025, title = {Bronsted-acid-mediated divergent reactions of betti bases with indoles: an approach to chromeno[2,3-b]indoles through intramolecular dehydrogenative C2-alkoxylation of indole}, journal = {European Journal of Organic Chemistry}, number = {20}, year = {2016}, month = {JUL}, pages = {3441-3448}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

Divergent reactions of various 1-(aminoalkyl) naphthols and 2-(aminoalkyl) phenols (commonly known as Betti bases) with indoles under Bronsted acid catalysis is reported. With the reaction strategies, one can efficiently synthesize important indole derivatives such as 3-(alpha,alpha-diarylmethyl)indoles and chromeno[2,3-b]indoles. Furthermore, we disclose here a new C-C bond-cleavage reaction, in which naphthol and phenol behave as leaving groups to produce diarylmethanes. Inexpensive reagents such as p-toluenesulfonic acid monohydrate and molecular iodine are used to catalyze the reactions. No metal catalyst is required. The starting material of the reactions, Betti bases, are easily prepared from a three-component reaction of naphthol/phenol, aldehydes, and secondary amines. The mechanisms for the reactions are established through some control experiments. Quinone methide is the key intermediate for all the reactions reported herein.

}, keywords = {Betti bases, C-O bond formation, Dearylation, Fused-ring systems, nitrogen heterocycles}, issn = {1434-193X}, doi = {10.1002/ejoc.201600546}, author = {Deb, Mohit L. and Pegu, Choitanya Dev and Deka, Bhaskar and Dutta, Prantu and Kotmale, Amol S. and Baruah, Pranjal K.} } @article {45600, title = {Unusual route to synthesize indolizines through a domino SN2/michael addition reaction between 2-mercaptopyridine and nitroallylic acetates}, journal = {European Journal of Organic Chemistry}, year = {2019}, month = {JAN}, pages = {765-769}, type = {Article}, abstract = {

A straightforward synthesis of indolizines has been demonstrated from the reaction of 2-mercaptopyridine and nitroallylic acetates in the presence of a base. The products were obtained in good isolated yield under relatively mild reaction conditions. The mechanistic insight of the reaction has been revealed by performing some control experiments demonstrating that the reaction is initiated by a sequential SN2/Michael addition reaction followed by removal of the sulfur moiety.

}, keywords = {domino reactions, Michael addition, nitrogen heterocycles, nucleophilic substitution, synthetic methods}, issn = {1434-193X}, doi = {10.1002/ejoc.201801426}, author = {Roy, S.} }