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Lewis acid‐mediated defluorinative [3+2] cycloaddition/aromatization cascade of 2,2‐difluoroethanol systems with nitriles
Author(s) -
Hsieh MinTsang,
Lee KuoHsiung,
Kuo ShengChu,
Lin HuiChang
Publication year - 2018
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201701581
Subject(s) - chemistry , cycloaddition , aromatization , lewis acids and bases , bond cleavage , cascade reaction , derivatization , surface modification , ring (chemistry) , substrate (aquarium) , fluorine , combinatorial chemistry , organic chemistry , catalysis , oceanography , high performance liquid chromatography , geology
The properties of C−F bonds, including high thermal and chemical stability, make derivatization of organic fluorine‐containing compounds by the activation of the C−F bond and subsequent functionalization quite challenging. We herein report a Lewis acid‐mediated defluorinative cycloaddition/aromatization cascade of 2,2‐difluoroethanols with nitriles as a novel synthetic method for the preparation of 2,4,5‐trisubstituted oxazoles. This reaction, which involves cleavage of two C−F bonds and the consecutive formation of C−O and C−N bonds in a one‐pot fashion, features a broad substrate scope and moderate to high reaction yields. Mechanistic studies revealed that the reaction is initiated by the Lewis acid‐mediated ring closure of the 2,2‐difluoroethanol to produce the fluoroepoxide intermediate.