Recent Trends in Triarylborane Chemistry: Diversification of Structures and Reactivity via meta-Substitution of the Aryl Groups

This Short Review summarizes the synthesis and applications of triarylboranes (BAr₃), including both homoleptic and heteroleptic species, with a focus on the modification of their electronic and structural properties via the introduction of meta-substituents with respect to the B atoms to their Ar groups. This approach constitutes a complementary alternative to conventional strategies for the design of BAr₃, which are usually based on a modification of their ortho- and/or para-substituents. An initial analysis revealed that CH₃ and F are the most common meta-substituents in hitherto reported BAr₃ (apart from the H atom). Thus, an extensive exploration of other substituents, e.g., heavier halogens, longer or functionalized alkyl groups, and aryl groups, will increase our knowledge of the structure and reactivity of BAr₃ and eventually lead to a range of new applications.

1 Introduction

2 Scope of this Review

2.1 The Electronic and Steric Influence of meta-Substituents

2.2 Molecular Transformations Mediated by meta-Substituted Boranes

2.3 Other Examples of meta-Functionalization of BAr₃

3 Conclusions and Perspectives