Cinchona Alkaloid-Catalyzed Asymmetric Trifluoromethylation of Alkynyl Ketones with Trimethylsilyl Trifluoromethane
摘要:
The first catalytic enantioselective trifluoromethylation of alkynyl ketones 1 with (trifluoromethyl)trimethylsilane is disclosed by an operationally simple procedure, based on the combination of ammonium bromide of bis-cinchona alkaloids with Me4NF to afford trifluoromethyl-substituted tertiary propargyl alcohols (up to 96% ee), which are the important chiral building blocks for pharmaceuticals. Biologically attractive aryl heteroaryl trifluoromethyl carbinols were also synthesized.
Solvent free one pot syntheses of highly substituted propargyl ethers and propargyl amines from propargyl alcohols catalyzed by recyclable alumina-sulfuric acid
develop an efficient protocol for the solvent-free synthesis of a wide variety of highlysubstituted propargyl ethers and amines using alumina-sulfuric acid as a recyclable heterogeneous solid acidcatalyst has been presented. This mild protocol tolerates a good number of acid-sensitive moieties and can be applicable to a diverse range of alcohols and amines accommodating a variety of substitution patterns