cobalt-catalyzed hetero-biaryl couplingreaction between aryl chlorides and arylmagnesium halides with unprecedented selectivity has been developed. The protocol utilizes 1 mol% of cheap Co(acac)3 as pre-catalyst and effects clean reactions of deactivated chlorostyrenes with only 1.1 equiv. of the Grignard reagent under mild conditions (30 °C, 5–30 min). Highly chemoselective reactions were realized even in
Herein, we report an unprecedented regiospecific oxidative Mizoroki-Heck type reaction for the synthesis of α-difluoromethyl homoallylic alcohols. The reaction shows broad substrate scopes and high functional group tolerance. Late-stage functionalization of complex biologically active molecules demonstrates the synthetic potential of this transformation. Mechanistic study supports the involvement of
Chlorostyrenes in Iron-Catalyzed Biaryl Coupling Reactions
作者:Samet Gülak、Axel Jacobi von Wangelin
DOI:10.1002/anie.201106110
日期:2012.2.6
An effective protocol for iron‐catalyzed biaryl syntheses by couplingchlorostyrenes with aryl Grignard reagents requires only mild reaction conditions and tolerates various functional groups. The underlying activation of deactivated aryl chlorides proceeds through a rate‐determining coordination of the catalyst to the vinyl substituent and subsequent haptotropic migration along the conjugated π system
Palladium Acetate Catalyzed Oxidative Aromatization of Methylenecyclopropanes
作者:Min Jiang、Yin Wei、Min Shi
DOI:10.1002/ejoc.201000299
日期:2010.6
Isopropenylbiaryl derivatives were produced in moderate to good yields at high temperature from the reaction of methylenecyclopropanes (MCPs) 1 in the presence of palladiumacetate under ambient atmosphere by tandem intramolecular C-H and C-C bond activation and aromatization through dehydrogenated rearrangement of MCPs 1. A plausible mechanism has been proposed on the basis of deuterium labeling and
Selective Synthesis of Substituted Pyridines and Pyrimidines through Cascade Annulation of Isopropene Derivatives
作者:Jian Li、Jiaming Li、Runfa He、Jiasheng Liu、Yang Liu、Lu Chen、Yubing Huang、Yibiao Li
DOI:10.1021/acs.orglett.2c00124
日期:2022.3.4
Diverse substituted pyridines and pyrimidines with high selectivity were obtained using a concise and efficient protocol developed herein. The reaction proceeds via metal-free cascade annulation of isopropene derivatives. Using isopropene derivatives as C3 synthons, NH4I as the “N” source, and formaldehyde or dimethyl sulfoxide as the carbon source, this reaction realizes the efficient formation of