Synthesis of C2-Symmetric Benzimidazolium Salts and Their Application in Palladium-Catalyzed Enantioselective Intramolecular α-Arylation of Amides
作者:Weiping He、Wei Zhao、Bihui Zhou、Haifeng Liu、Xiangrong Li、Linlin Li、Jie Li、Jianyou Shi
DOI:10.3390/molecules21060742
日期:——
A series of C₂-symmetric chiral benzimidazoliumsalts, the precursor of N-heterocycliccarbeneligands, were designed and synthesized from 1,2-dibromobenzene. In situ prepared corresponding carbenes were tested in the asymmetric palladium-catalyzed intramolecular α-arylation of amides, affording chiral diarylmethanols with high yields and moderate enantioselectivities.
Palladium-Catalyzed Enantioselective α-Arylation and α-Vinylation of Oxindoles Facilitated by an Axially Chiral P-Stereogenic Ligand
作者:Alexander M. Taylor、Ryan A. Altman、Stephen L. Buchwald
DOI:10.1021/ja903880q
日期:2009.7.29
The enantioselective alpha-arylation and alpha-vinylation of oxindoles catalyzed by Pd and a biarylmonophosphine ligand with both axial and phosphorus-based chirogenicity is reported. The resultant quaternary carbon stereocenters are formed in high enantiomeric excess and the conditions tolerate a range of substitution on both the oxindole and the aryl/vinyl coupling partners.
Bulky Chiral Carbene Ligands and Their Application in the Palladium-Catalyzed Asymmetric Intramolecular α-Arylation of Amides
作者:E. Peter Kündig、Thomas M. Seidel、Yi-xia Jia、Gérald Bernardinelli