Efficient conversion of acids and esters to amides and transamidation of primary amides using OSU-6
作者:Baskar Nammalwar、Nagendra Prasad Muddala、Field M. Watts、Richard A. Bunce
DOI:10.1016/j.tet.2015.10.016
日期:2015.12
with strong Bronsted acid properties, has been used to promote the high-yield conversion of carboxylic acids and esters to carboxamides as well as transamidations of primary amides in a one-pot solventless approach. A metal-free heterogeneous catalyst that promotes all of these processes has not been previously reported. OSU-6 enables these transformations to proceed in shorter times and at lower temperatures
A para-selective CH amidation of simplearenes with nitriles has been developed. By increasing the amount of arenes, a further meta-selective CH arylation of the produced amides occurred. Both steric and electronic effects are utilized to control the selectivity, resulting in only para-selectiveamidation products. The readily available nitriles as amidation reagents instead of amides makes the synthesis
Non-harmful Povidone iodine (PVP-I) was applied in the transamidation to gain N-substituted amidesfrom various primary amides and amines. Diverse aromatic, heterocyclic and aliphatic primary amides/amines were applied in our developed method and more than 45 N-substituted amides were obtained with excellent yields in most cases. Several drugs such as Melatonin and Efaproxiral were successfully acquired