Practical Synthesis of Amides via Copper/ABNO-Catalyzed Aerobic Oxidative Coupling of Alcohols and Amines
作者:Susan L. Zultanski、Jingyi Zhao、Shannon S. Stahl
DOI:10.1021/jacs.6b03931
日期:2016.5.25
A modular Cu/ABNO catalystsystem has been identified that enables efficient aerobic oxidative coupling of alcohols and amines to amides. All four permutations of benzylic/aliphatic alcohols and primary/secondary amines are viable in this reaction, enabling broad access to secondary and tertiary amides. The reactions exhibit excellent functional group compatibility and are complete within 30 min-3
water, the industrial protease Alcalase allows selective synthesis of α-carboxylic acid methyl, ethyl, benzyl, allyl, 2-(trimethylsilyl)ethyl, and tert-butyl esters of aminoacids and peptides under mild conditions in very high yields. The purified yields range from 72% to 92%. enzymes - aminoacids - esterification - esters - protecting groups
activation for this reaction. The benzamides were directly formed from alcohols and amine hydrochloride salts in short reaction times with yields up to 84 % and TOFs (turnover frequencies) up to 33.6 h–1. Among the examined transition metals, only nontoxic and inexpensive FeCl2·4H2O together with caffeine as a stabilizing ligand provided a uniquely efficient catalyticsystem for the transformation. Natural
in the synthesis of natural products and biologically active compounds. Unfortunately, these reactions often require the use of large quantities of volatile and/or toxic solvents, either for the reaction, purification or isolation of the products. Herein we describe and discuss the possibility of completely eliminating the use of organic solvents for the synthesis, purification and isolation of products
The synthesis of various amides has been realised avoiding the use of any organic solvent from activation of carboxylic acids with CDI to isolation of the amides. Mechanochemistry was the key point of the process allowing rapid formation of the amide bond and efficient water-based purification of the final products.