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Metal‐Free Directed C−H Borylation of Pyrroles
Author(s) -
Wang ZhengJun,
Chen Xiangyang,
Wu Lei,
Wong Jonathan J.,
Liang Yong,
Zhao Yue,
Houk Kendall N.,
Shi Zhuangzhi
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202016573
Subject(s) - borylation , steric effects , chemistry , selectivity , combinatorial chemistry , environmentally friendly , chelation , metal , stereochemistry , organic chemistry , catalysis , ecology , alkyl , aryl , biology
Robust strategies to enable the rapid construction of complex organoboronates in selective, practical, low‐cost, and environmentally friendly modes remain conspicuously underdeveloped. Here, we develop a general strategy for the site‐selective C−H borylation of pyrroles by using only BBr 3 directed by pivaloyl groups, avoiding the use of any metal. The site‐selectivity is generally dominated by chelation and electronic effects, thus forming diverse C2‐borylated pyrroles against the steric effect. The formed products can readily engage in downstream transformations, enabling a step‐economic process to access drugs such as Lipitor. DFT calculations (wB97X‐D) demonstrate the preferred positional selectivity of this reaction.