Hindered Ureas as Masked Isocyanates: Facile Carbamoylation of Nucleophiles under Neutral Conditions
作者:Marc Hutchby、Chris E. Houlden、J. Gair Ford、Simon N. G. Tyler、Michel R. Gagné、Guy C. Lloyd-Jones、Kevin I. Booker-Milburn
DOI:10.1002/anie.200904435
日期:2009.11.2
better: Sterically hindered dialkyl ureas undergo nucleophilic substitution at dramatically faster rates than their less hindered counterparts (see scheme). Steric decompression upon the formation of an intermediate isocyanate can explain this counterintuitive behavior. These hindered ureas can be considered as masked reagents that liberate reactive isocyanates in situ.
Beyond conventional routes, an unprecedented metal-free chemoselective synthesis of anthranilate esters via a multicomponent reaction (MCR) strategy
作者:Satavisha Sarkar、Abu T. Khan
DOI:10.1039/c5cc03369a
日期:——
A hitherto unreported route for the synthesis of anthranilate esters is demonstrated using 2-nitrobenzaldehyde, malonitrile and an alcohol or amine via a metal and oxidant free multicomponent reaction (MCR) strategy.