Synthesis 2022; 54(15): 3328-3340
DOI: 10.1055/a-1816-3334
short review

Catalyst Engineering through Heterobidentate (N–X-Type) Ligand Design for Iridium-Catalyzed Borylation

Md Emdadul Hoque
,
Mirja Md Mahamudul Hassan
,
Chabush Haldar
,
Sayan Dey
,
Saikat Guria
,
Jagriti Chaturvedi
,
This work was supported by grants from the Science and Engineering Research Board – Core Research Grant (SERB-CRG; CRG/2018/000133), Science and Engineering Research Board – Scientific and Useful Profound Research Advancement (SERB-SUPRA; SPR/2019/000158), and Science and Engineering Research Board – Science and Technology Award for Research (SERB-STAR; STR/2019/000045). M.E.H. thanks SERB-SUPRA for an RA fellowship, M.M.M.H. thanks the University Grants Commission (UGC) for an SRF, C.H. thanks Council of Scientific and Industrial Research (CSIR) for an SRF, S.D. and S.G. thanks the CSIR for a JRF fellowship, J.C. thanks UGC for an SRF. B.C. thanks SERB-STAR for an award.


Abstract

Iridium-catalyzed C–H activation and borylation reactions operate under mild conditions that enable easy and atom-economical installation of the versatile boronate ester group in (het)arenes and alkanes. The standard catalytic system for iridium-catalyzed borylation uses [Ir(cod)(OMe)]2 as a precatalyst, a bipyridine type ligand, and B2pin2 or HBpin as the borylating agent. Initially, a bipyridine-ligated trisboryl–iridium complex is generated that enables the borylation reaction and the regioselectivity is mainly governed by the sterics of substituents present on the ring. As a result, monosubstituted and 1,2-disubstituted arenes give mixtures of isomers. Significant efforts by several research groups have overcome the selectivity issue for directed proximal C–H borylation by introducing a directing group and newly developed ligands. This short review aims to summarize recent elegant discoveries in directed C(sp2)–H and C(sp3)–H borylation by using heterobidentate ligand (P/N–Si, N–B, and N–C) coordinated iridium catalysts.

1 Introduction

2 Iridium-Catalyzed Directed C–H Borylation of C(sp2)–H Bonds

3 Iridium-Catalyzed Directed C–H Borylation of C(sp3)–H Bonds

4 Conclusions



Publication History

Received: 07 March 2022

Accepted after revision: 04 April 2022

Accepted Manuscript online:
04 April 2022

Article published online:
16 May 2022

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