Boron(III)‐Catalyzed C2‐Selective C−H Borylation of Heteroarenes. Issue 45 (12th October 2018)

• Record Type: Journal Article
• Authors: Zhong, Qi; Qin, Shengxiang; Yin, Youzhi; Hu, Jiajun; Zhang, Hua
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 45(2018)
• Page Start: 14891
• Page End: 14895
• Publication Date: 2018-10-12
• Subjects: boron -- heteroarenes -- homogeneous catalysis -- reaction mechanisms -- synthetic methods; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201808590
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A BF3 ⋅Et2 O‐catalyzed C2‐selective C−H borylation of indoles with bis(pinacolato)diboron was developed to afford indole‐2‐boronic acid pinacol esters. A variety of functional groups were tolerated, and other heteroarenes like pyrrole and benzo[ b ]thiophene were also suitable substrates. An electrophilic substitution mechanism was proposed based on the preliminary mechanistic studies. This novel transformation utilizes simple and cheap BF3 ⋅Et2 O as catalyst and exhibits unusual C2 regioselectivity, providing a significant non‐transition‐metal‐catalyzed C−H borylation and an efficient method towards the synthesis of C2‐functionalized heteroarenes. Abstract : Busy B : A BF3 ⋅Et2 O‐catalyzed C2‐selective C−H borylation of indoles, as well as other heteroarenes, with bis(pinacolato)diboron was developed. An electrophilic substitution mechanism is proposed based on preliminary mechanistic studies. This transformation provides a significant non‐transition‐metal‐catalyzed C−H borylation method for the synthesis of C2‐functionalized heteroarenes.