General Synthesis of Chiral α,α-Diaryl Carboxamides by Enantioselective Palladium-Catalyzed Cross-Coupling
作者:Bowen Li、Muinat A. Aliyu、Zhenhua Gao、Tiejun Li、Wei Dong、Junchen Li、Enxue Shi、Wenjun Tang
DOI:10.1021/acs.orglett.0c01489
日期:2020.7.2
chiral α,α-diaryl carboxamides is developed by enantioselective cross-coupling between 2-bromo-2-aryl carboxamides and arylboronicacids, leading to a series of chiral α,α-diaryl carboxamides with various electronic properties and functionalities in moderate to excellent enantioselectivities and yields. The employment of a sterically bulky chiral P,P═O ligand L2 is critical for the reactivity and selectivity
Carbon–carbon bond-forming reactions of α-carbonyl carbocations: exploration of a reversed-polarity equivalent of enolate chemistry
作者:Ping-Shan Lai、Joshua A. Dubland、Mohammed G. Sarwar、Michael G. Chudzinski、Mark S. Taylor
DOI:10.1016/j.tet.2011.07.065
日期:2011.9
Carbon–carbon bond-forming reactions of putative α-carbonyl carbocation intermediates generated by Lewis acid- or silver-promoted ionizations of toluenesulfonate or halide leaving groups are described. This under-exploited mode of reactivity represents an ‘umpolung’ of conventional enolate chemistry, and enables C–C bond construction in both intra- and intermolecular contexts. Attempts to develop diastereoselective