Unprecedented Catalytic Asymmetric Reduction of N−H Imines
摘要:
Addition of lithium bis(trimethylsilyl)amide to perfluorinated ketones 1a-j affords (E)-N-TMS-ketimines 2a-j that are reduced in situ to afford racemic perfluoromethylated amine hydrochloride salts 3a-j in 54-97% yields. Solvolysis of the N-Si bond in MeOH leads to formation of bench-stable, isolable N-H imine Z/E isomer mixtures along with a methanol adduct. Enantioselective reduction of these three-component mixtures provides the first catalytic asymmetric synthesis of trifluoromethylated amines in 72-95% yields and 75-98% ee.
Unprecedented Catalytic Asymmetric Reduction of N−H Imines
作者:Francis Gosselin、Paul D. O'Shea、Stéphanie Roy、Robert A. Reamer、Cheng-yi Chen、Ralph P. Volante
DOI:10.1021/ol047431x
日期:2005.1.1
Addition of lithium bis(trimethylsilyl)amide to perfluorinated ketones 1a-j affords (E)-N-TMS-ketimines 2a-j that are reduced in situ to afford racemic perfluoromethylated amine hydrochloride salts 3a-j in 54-97% yields. Solvolysis of the N-Si bond in MeOH leads to formation of bench-stable, isolable N-H imine Z/E isomer mixtures along with a methanol adduct. Enantioselective reduction of these three-component mixtures provides the first catalytic asymmetric synthesis of trifluoromethylated amines in 72-95% yields and 75-98% ee.
A Simple and Efficient Preparation of 3-Aryl-3-Trifluoromethyl-3H-Diazirinyl Sulfoxides and Sulfones
作者:John B.C. Findlay、Colin W.G. Fishwick、Ian D. Kersey、Peter Ward
DOI:10.1055/s-1995-3956
日期:1995.5
All regioisomers of 3-aryl-3-trifluoromethyl-3H-diazirinyl sulfoxides and sulfones have been prepared in five steps from the corresponding bromothioanisoles in excellent overall yields. The key step involves a simultaneous oxidation of sulfide and diaziridine moieties respectively, to yield either the diazirine sulphoxide or sulphone, depending on reaction conditions.