Selective Hydro‐ and Deuterodechlorination of Trichloroacetamides under Controlled Electrochemical Conditions To Prepare Mono‐, Di‐, and Deuterochloroacetamides
摘要:
Mono and dichloro acetamides were prepared via hydrodechlorination reaction of trichloroacetamides under controlled electrochemical conditions. The reactions were carried out in an undivided cell with constant current flow using n‐Bu4NI as supporting electrolyte and methanol as solvent and proton source. Deuterodechlorination of trichloroacetamide was also successful using methanol‐d4 as solvent under identical electrochemical conditions.
A range of 1-aryl-allylamines were prepared in moderate to excellent enantioselectivity (ee 63.5%-> 99.9%) using lipase B from a Candida antarctica catalyzed resolution of racemic amines. This is the first time that CaLB has been used for the resolution of 1-aryl-allylamines. Racemic amines were prepared starting from aromatic aldehydes with a [3,3]-sigmatropic rearrangement of the acyclic imidates as the key step followed by trichloroacetamidate hydrolysis. Aldehydes were converted into acrylic esters using Knoevenagel reaction. After reduction, the corresponding alcohols were used for the preparation of trichloroacetimidates, which were then used in an Overman rearrangement. (C) 2011 Elsevier Ltd. All rights reserved.