@article { ISI:000324316300042, title = {Identification of molecular crystals capable of undergoing an acyl-transfer reaction based on intermolecular interactions in the crystal lattice}, journal = {Chemistry-A European Journal}, volume = {19}, number = {38}, year = {2013}, month = {SEP}, pages = {12867-12874}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Investigation of the intermolecular acyl-transfer reactivity in molecular crystals of myo-inositol orthoester derivatives and its correlation with crystal structures enabled us to identify the essential parameters to support efficient acyl-transfer reactions in crystals: 1)the favorable geometry of the nucleophile (OH) and the electrophile (CO) and 2)the molecular assembly, reinforced by CH interactions, which supports a domino-type reaction in crystals. These parameters were used to identify another reactive crystal through a data-mining study of the Cambridge Structural Database. A 2:1 co-crystal of 2,3-naphthalene diol and its di-p-methylbenzoate was selected as a potentially reactive crystal and its reactivity was tested by heating the co-crystals in the presence of solid sodium carbonate. A facile intermolecular p-toluoyl group transfer was observed as predicted. The successful identification of reactive crystals opens up a new method for the detection of molecular crystals capable of exhibiting acyl-transfer reactivity.

}, keywords = {Acylation, domino reactions, intermolecular interactions, solid-state reactions, X-ray diffraction}, issn = {0947-6539}, doi = {10.1002/chem.201301058}, author = {Tamboli, Majid I. and Krishnaswamy, Shobhana and Gonnade, Rajesh G. and Shashidhar, Mysore S.} } @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.} } @article {46628, title = {Apparent umpolung reactivity of indole through [Au]-catalysed cyclisation and lewis-acid-mediated allylation}, journal = {Chemistry-A European Journal}, volume = {26}, year = {2020}, month = {DEC}, pages = {17171-17175}, type = {Article}, abstract = {

The sequential functionalization of indole C2 and C3 in an umpolung fashion was executed with a predesigned substrate and choice of reagents. The developed method comprises gold-catalysed alkynol cycloisomerisation/intramolecular addition of C2 of indole and subsequent BF3.OEt2-mediated regioselective C3 allylation, resulting in the synthesis of the functionalized indoloisoquinolinone scaffold. The reaction involves 5-endo-alkynol cycloisomerisation and the dearomative addition of indole C2 to the intermediate oxocarbenium cation, which results in two equilibrating fused and spiropentacyclic intermediates, which upon treatment with allyl silane in the presence of BF3.OEt2, undergo selective indole C3 allylation. Other nucleophiles, such as hydride, azide and indole, were also found to be compatible with this process.

}, keywords = {Allylation, cyclization, domino reactions, Gold, umpolung}, issn = {0947-6539}, doi = {10.1002/chem.202003441, Early Access Date = NOV 2020}, author = {Shinde, Mahesh H. and Ramana, Chepuri V.} } @article {47631, title = {Construction of two-component chemically reactive supramolecular assemblies-acyl migration reactions in cocrystals of napthalene-2,3-diol and its diesters}, journal = {ChemPlusChem}, volume = {86}, year = {2021}, month = {AUG}, pages = {1128-1134}, type = {Article}, abstract = {Reactions in solids are of contemporary interest due to applications in pharmaceutical industries to environmental sustainability. Although several reactive crystals that support chemical reactions have been identified and characterized, the same cannot be said about reactive cocrystals. Earlier we correlated the facile acyl group transfer reactions in crystals with supramolecular parameters obtained from the crystal structures. The structure-reactivity correlation revealed the requirement of proper juxtaposition of electrophile (C=O) and the nucleophile (OH) with distance (similar to 3.2 angstrom) and angle (similar to 90 degrees) along the chain structure. The current article describes the preparation of cocrystals that are capable of supporting intermolecular acyl group transfer reactions in a group of structurally similar molecules. The cocrystals of naphthalene 2,3-diol and its corresponding diesters showed a facile solid state acyl transfer reaction, which has been well correlated with their crystal structures.}, keywords = {Acylation, domino reactions, intermolecular interactions, reaction in cocrystal, solid-state reactions, X-ray diffraction}, issn = {2192-6506}, doi = {10.1002/cplu.202100139}, author = {Bahadur, Vir and Gonnade, Rajesh G. and Tamboli, I. Majid and Krishnaswamy, Shobhana and Shashidhar, Mysore S.} }