Selective Formal Transesterification of Fluorinated 2-(Trimethylsilyl)ethyl α-Imino Esters Mediated by TBAF
作者:Santos Fustero、María Sánchez-Roselló、Vanessa Rodrigo、Amador García、Silvia Catalán、Carlos del Pozo
DOI:10.1021/jo800567a
日期:2008.7.1
The scope of the transesterification reaction between β-fluorinated α-imino esters and various electrophiles in the presence of TBAF as fluorine source is described. The reaction is highly selective for alkyl iodides, bromides, and mesylates, while alkyl chlorides react at a significantly slower rate and tosylates do not react under the reaction conditions. This methodology represents a simple and
2-(N-arylimino)-3,3,3-trifluoropropanoic acid esters with a chiral oxazaborolidine catalyst and subsequent oxidative removal of N-aromatic moiety with retention of the configuration. Detailed optimization studies revealed that the effects of solvents, temperature, and the structural modification of the substrate were drastic on the enantioselectivity. The absolute configuration of 1 was determined to be (R) by
Homologation of trinuoroacetimidoyl iodides and the related perfluoro-compounds by palladium-catalyst under CO(1atm)-atmosphere in the presence of alcohols gives alpha-imino perfluoroatkanoates which are transformed to alpha-amino perfluoroalkanoic acids.
N-TMS-β,β-difluoroenamines: Electrochemical preparation and its transformation
作者:Kenji Uneyama、Tsuyoshi Kato
DOI:10.1016/s0040-4039(97)10613-x
日期:1998.2
The first preparation of N-trimethylsilylated beta,beta-difluoroenamines (2) from the trifluoromethyl imines (1) by electrochemical reduction and a preliminary study on alkylation of 2 for the synthesis of difluoromethylene compounds are described. (C) 1998 Elsevier Science Ltd. All rights reserved.