RESUMEN
Herein we describe the design and synthesis of a novel family of bifunctional, chiral bicyclo[2.2.1]heptadiene ligands bearing aryl and secondary amido groups, and demonstrate their usefulness in the RhI -catalyzed enantioselective addition reaction of arylboronic acids to N-diphenylphosphinyl (N-DPP)-protected aldimines. Unlike the analogous RhI -catalysts comprising diene ligands substituted with aryl and carboxylic ester groups, or only with aryl groups, the addition reaction proceeded with high stereoselectivity. The protocol tolerated a range of N-DPP-aldimines and arylboronic acids, producing the desired optically active N-DPP-protected amines with yields between 31-99 % and with ee values up to 91-99 %. The synthetic utility of the method was demonstrated by the conversion of N-DPP-protected amine 3 ae into the antifungal agent, bifonazole (13).
Asunto(s)
Aminas/química , Antifúngicos/síntesis química , Imidazoles/química , Rodio/química , Antifúngicos/química , Ácidos Borónicos , Catálisis , Cristalografía por Rayos X , Imidazoles/síntesis química , Ligandos , Conformación Molecular , Polienos/química , EstereoisomerismoRESUMEN
ß,γ-Unsaturated ketones are an important class of organic molecules. Herein, copper catalysis has been developed for the synthesis of ß-γ-unsaturated ketones through 1,2-addition of α-carbonyl iodides to alkynes. The reactions exhibit wide substrate scope and high functional group tolerance. The reaction products are versatile synthetic intermediates to complex small molecules. The method was applied for the formal synthesis of (±)-trichostatinâ A, a histone deacetylase inhibitor.