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Thioamide‐Directed Cobalt(III)‐Catalyzed Selective Amidation of C(sp 3 )−H Bonds
Author(s) -
Tan Peng Wen,
Mak Adrian M.,
Sullivan Michael B.,
Dixon Darren J.,
Seayad Jayasree
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201709273
Subject(s) - chemistry , thioamide , catalysis , regioselectivity , metalation , pyridine , aryl , medicinal chemistry , deprotonation , cobalt , alkyl , combinatorial chemistry , carboxylate , stereochemistry , organic chemistry , ion
A mild, oxidant‐free, and selective Cp*Co III ‐catalyzed amidation of thioamides with robust dioxazolone amidating agents via C(sp 3 )−H bond activation to generate the desired amidated products is reported. The method is efficient and allows for the C−H amidation of a wide range of functionalized thioamides with aryl‐, heteroaryl‐, and alkyl‐substituted dioxazolones under the Cp*Co III ‐catalyzed conditions. The observed regioselectivity towards primary C(sp 3 )−H activation is supported by computational studies and the cyclometalation is proposed to proceed by means of an external carboxylate‐assisted concerted metalation/deprotonation mechanism. The reported method is a rare example of the use of a directing group other than the commonly used pyridine and quinolone classes for Cp*Co III ‐catalyzed C(sp 3 )−H functionalization and the first to exploit thioamides.