Synthesis 2025; 57(03): 495-521
DOI: 10.1055/a-2343-0780
review

Directing-Group-Assisted Transition-Metal-Catalyzed Selective BH Functionalization of o-Carboranes

Jie Zhang
a   Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin NT, Hong Kong, P. R. of China
,
Zuowei Xie
b   Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. of China
› Author Affiliations
Financial support from the Research Grants Council of the Hong Kong Special Administration Region (Project No. 14305420 to JZ), the Shenzhen Science and Technology Program (Project No. QTD20221101093558015 to ZX), and the National Natural Science Foundation of China (Project No. 22331005 to ZX) are gratefully acknowledged.


Abstract

Carboranes are a type of molecular clusters consisting of carbon, hydrogen, and boron atoms. They possess unique characteristics, such as three-dimensional aromaticity, icosahedral geometry, and robustness. Functionalized carboranes have been utilized in various fields, including medicine, materials, and organometallic/coordination chemistry. In this context, selective functionalization of o-carboranes has received tremendous attention, specifically in the regio- and enantioselective modification of the ten chemically similar BH vertices within the carborane cage. In recent years, significant progress has been made in catalytic vertex-specific BH functionalization, as well as achieving enantioselective functionalization of the cage BH. This review provides an overview of the recent advancements in this research field.

1 Introduction

2 Carboxy-Assisted BH Functionalization

2.1 Formation of B–C Bonds

2.2 Formation of B–N Bonds

2.3 Formation of B–O Bonds

2.4 Formation of B–X Bonds

2.5 Consecutive Formation of B–C and B–Y (Y = N, O) Bonds

3 N-Based Directing-Group-Assisted B–H Functionalization

3.1 Acylamino as a Directing Group

3.2 Amide as a Directing Group

3.3 Pyridyl as a Directing Group

3.4 Imine as a Directing Group

4 Phosphinyl-Assisted Cage B–H Functionalization

5 Bidentate-Directing-Group-Assisted B–H Functionalization

6 Other Directing-Group-Assisted B–H Functionalization

7 Conclusions



Publication History

Received: 06 May 2024

Accepted after revision: 11 June 2024

Accepted Manuscript online:
11 June 2024

Article published online:
15 July 2024

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