A versatile and practical methodology to access beta amino and beta-hydroxy alpha,alpha-difluoro carbonyl compounds using indium metal is described. This methodology has been successfully applied to a broad range of substrates including aldehydes, ketones, and imines, affording the corresponding and highly valuable gem-difluoto esters. The wide substrate scope highlights the chemoselectivity of the process.
The simple and selective synthesis of 3-amino-2,2-difluorocarboxylic esters and difluoro-β-lactams using ethyl bromodifluoroacetate in the presence of rhodium catalyst
Treatment of imines (5) with ethyl bromodifluoroacetate (1) and Et2Zn in the presence of RhCl(PPh3)(3) in anhydrous medium gave difluoro-beta-lactams (7) in good to excellent yields, while 3-amino-2,2-difluorocarboxylic esters (6) were obtained in good yields by adding MgSO(4)(.)7H(2)O to the reaction medium. (c) 2005 Elsevier Ltd. All rights reserved.