Cooperative catalysis by carbenes and Lewis acids in a highly stereoselective route to γ-lactams
作者:Dustin E. A. Raup、Benoit Cardinal-David、Dane Holte、Karl A. Scheidt
DOI:10.1038/nchem.727
日期:2010.9
more catalytic cycles operate concurrently to achieve one overall transformation, has great potential in enhancing known reactivity and driving the development of new chemical reactions with high value. In this disclosure, a cooperative N-heterocyclic carbene/Lewis acid catalytic system promotes the addition of homoenolate equivalents to hydrazones, generating highly substituted γ-lactams in moderate
Enantioselective <i>N</i>-Heterocyclic Carbene Catalysis via Acyl Azolium without Exogenous Oxidants
作者:Jing Cao、Rachel Gillard、Azar Jahanbakhsh、Martin Breugst、David W. Lupton
DOI:10.1021/acscatal.0c02705
日期:2020.10.16
An approach to the α,β-unsaturatedacylazolium has been developed that exploits N-heterocyclic carbenes (NHCs) and acyl fluorides, without additional oxidants, bases, or preactivated pro-nucleophiles. These conditions have been applied in four classes of NHC-catalyzed reaction. In all cases, the expected products were produced with high yield and enantioselectivity, using two sets of closely related
Organocatalytic Enantioselective γ-Aminoalkylation of Unsaturated Ester: Access to Pipecolic Acid Derivatives
作者:Jianfeng Xu、Zhichao Jin、Yonggui Robin Chi
DOI:10.1021/ol402358k
日期:2013.10.4
The direct gamma-carbon functionalization of alpha,beta-unsaturated esters via N-Heterocyclic Carbene (NHC) catalysis is disclosed. This catalytically generated nucleophilic gamma-carbon undergoes highly enantioselective additions to hydrazones. The resulting delta-lactam products can be readily transformed to optically enriched pipecolic acid derivatives.