Categories: C-Cl Bond Formation >
Synthesis of acyl chlorides
The conversion of carboxylic acids to their corresponding acid chlorides occurs rapidly in the presence a tertiary amine base and 3,3-dichlorocyclopropenes via aromatic cation-activated nucleophilic acyl substitution. The effect of cyclopropene substituents on the rate of conversion is examined. Conditions were developed for the preparation of acid sensitive acid chlorides.
D. J. Hardee, L. Kovalchuke, T. H. Lambert, J. Am. Chem. Soc., 2010, 132, 5002-5003.
The reaction of tert-butyl esters with SOCl2 at room temperature provides acid chlorides in very good unpurified yields, whereas benzyl, methyl, ethyl, and isopropyl esters are essentially unreactive.
J. A. Greenberg, T. Sammakia, J. Org. Chem., 2017, 82, 3245-3251.
Using an efficient visible-light photocatalysis-based method, a mixture of an aldehyde, tert-butyl hydrogen peroxide, and N-chlorosuccinimide afforded an acid chloride in the presence of Ru(bpy)3Cl2 as photocatalyst. A subsequent reaction with an amine provided the corresponding amide.
N. Iqbal, E. J. Cho, J. Org. Chem., 2016, 81, 1905-1911.