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Divergent, Stereospecific Mono‐ and Difluoromethylation of Boronic Esters
Author(s) -
Fasano Valerio,
Winter Nils,
Noble Adam,
Aggarwal Varinder K.
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202002246
Subject(s) - chemistry , stereospecificity , carbanion , decomposition , fluorine , combinatorial chemistry , organic chemistry , boronic acid , catalysis
There is considerable interest in incorporating fluorine into agrochemicals and pharmaceuticals to improve their biological properties. Whilst a number of methods have been reported for installing CH 2 F and CHF 2 groups, they are mainly limited to radical reactions, which are invariably racemic. Herein, we report the divergent, stereospecific reaction of fluoroiodomethyllithium with boronic esters to give α‐fluoro‐boronic esters. These unique intermediates can be readily transformed into the corresponding mono‐ or difluoromethylated compounds through proto‐ or fluorodeboronation, respectively. The use of the highly unstable fluoroiodomethyllithium was key to allowing rapid 1,2‐migration over competing decomposition of the carbanion. DFT calculations informed and supported the experimental findings.