Enantioselective Synthesis of Dihydropyridines Containing Quaternary Stereocenters Through Dearomatization of Pyridinium Salts
作者:Donovan J. Robinson、Sean P. Spurlin、John D. Gorden、Rashad R. Karimov
DOI:10.1021/acscatal.9b03874
日期:2020.1.3
a fully substituted stereogenic center is a challenging synthetic problem. We describe a strategy toward this problem involving dearomatization of N-alkylpyridinium salts using boronic acid nucleophiles. This dearomatization reaction is catalyzed by a rhodium(I)/BINAP catalytic system and delivers dihydropyridines that contain a fully substituted stereogenic center alpha to the ring nitrogen atom in
Rhodium-Catalyzed Asymmetric Functionalization of Quinoxalinium Salts
作者:Kacey G. Ortiz、Jensen S. Hammons、Rashad R. Karimov
DOI:10.1021/acs.orglett.3c03555
日期:2023.12.22
We report a rhodium-catalyzed asymmetric addition of aryl and alkenyl boronic acids to quinoxalinium salts that generates dihydroquinoxalines with high enantioselectivity. Functionalization of the reaction products, dihydroquinoxaline, allows the preparation of tetrahydroquinoxalines with various substitution patterns.