Oxidation of primary alcohols to acyl fluorides using BrF3
作者:Shlomo Rozen、Iris Ben-David
DOI:10.1016/0022-1139(95)03365-3
日期:1996.2
Aliphatic and alicyclicprimary alcohols when treated with BrF3 were rapidly oxidized to the corresponding acyl fluorides. The reaction is of an ionic nature. The main by-product was found to be the symmetrical ester which originates from the reaction between the acyl fluoride and unreacted starting alcohol.
The selective displacement of formyl hydrogen (–(C=O)–H) to fluorine in aliphatic aldehydes was successfully carried out electrochemically to give acyl fluorides in base-nHF (base: pyridine or Et3N, n = 3–6) electrolyte solution with or without solvents such as acetonitrile and sulfolane.
A highly chemoselective reductive deuteration of acylfluorides to provide α,α-dideuterio alcohols with exquisite levels of deuterium incorporation was developed using SmI2 and D2O as the deuterium source. This method introduces acylfluorides as attractive radical precursors for the generation of reactive acyl-type fluoride ketyls that should find widespread application in many synthetic strategies
While many carboxylic acids could be converted directly to acyl fluorides by using BrF3, the reaction with acyl chlorides was found to be of a more general nature and yields better results. Surprisingly, reacting t-butyl esters with brominetrifluoride also resulted in acyl fluorides in reasonable yields. The reactions were completed in a few seconds at 0 °C.