A novel practical cleavage of tert-butyl esters and carbonates using fluorinated alcohols
摘要:
Thermolytic cleavage of t-butyl esters and t-butyl carbonates was accomplished using TFE (2,2,2-trifluoroethanol) or HFIP (hexafluoroisopropanol) as solvent. Thus, a practical method to cleanly convert t-butyl esters and carbonates into the corresponding carboxylic acids, decarboxylated products, or alcohols in nearly quantitative yields was developed. The product is recovered by a simple solvent evaporation. The practicality of this methodology was demonstrated on alkyl, aryl, and heteroaromatic esters. (C) 2010 Elsevier Ltd. All rights reserved.
Asymmetric Construction of Quaternary Stereocenters by Direct Organocatalytic Amination of α-Substituted α-Cyanoacetates and β-Dicarbonyl Compounds
作者:Steen Saaby、Marco Bella、Karl Anker Jørgensen
DOI:10.1021/ja047704j
日期:2004.7.1
The first organocatalytic highly enantioselective reactions of substituted alpha-cyanoacetates and beta-dicarbonyl compounds with azodicarboxylates are reported. In the presence of 0.1-5 mol % of a quinidine-derived alkaloid beta-ICD, optically active quaternary hydrazine adducts are obtained in very high yields and with enantioselectivities up to >98% ee. A two-step procedure for the cleavage of the hydrazine N-N bond using SmI2 is also demonstrated.
[EN] DEPROTECTION OF BOC-PROTECTED COMPOUNDS<br/>[FR] DÉPROTECTION DE COMPOSÉS PROTÉGÉS PAR UN GROUPE BOC
申请人:HOFFMANN LA ROCHE
公开号:WO2010142616A2
公开(公告)日:2010-12-16
Organic compounds having t-butyl ester or BOC carbonate protecting groups are effectively deprotected by heating in a fluorinated alcohol solution.