1620078-17-2Relevant articles and documents
Transition state analysis of enantioselective br?nsted base catalysis by chiral cyclopropenimines
Bandar, Jeffrey S.,Sauer, Gregory S.,Wulff, William D.,Lambert, Tristan H.,Vetticatt, Mathew J.
supporting information, p. 10700 - 10707 (2014/08/18)
Experimental 13C kinetic isotope effects have been used to interrogate the rate-limiting step of the Michael addition of glycinate imines to benzyl acrylate catalyzed by a chiral 2,3-bis(dicyclohexylamino) cyclopropenimine catalyst. The reaction is found to proceed via rate-limiting carbon-carbon bond formation. The origins of enantioselectivity and a key noncovalent CH?O interaction responsible for transition state organization are identified on the basis of density functional theory calculations and probed using experimental labeling studies. The resulting high-resolution experimental picture of the enantioselectivity-determining transition state is expected to guide new catalyst design and reaction development.
