Group 13 exchange and transborylation in catalysis

Abstract

Catalysis is dominated by the use of rare and potentially toxic transition metals. The main group offers a potentially sustainable alternative for catalysis, due to the generally higher abundance and lower toxicity of these elements. Group 13 elements have a rich catalogue of stoichiometric addition reactions to unsaturated bonds but cannot undergo the redox chemistry which underpins transition-metal catalysis. Group 13 exchange reactions transfer one or more groups from one group 13 element to another, through σ-bond metathesis; where boron is both of the group 13 elements, this is termed transborylation. These redox-neutral processes are increasingly being used to render traditionally stoichiometric group 13-mediated processes catalytic and develop new catalytic processes, examples of which are the focus of this review.

Catalytic hydroboration of aldehydes and ketones with an electron-rich acyclic metallasilylene

“…12–15 In particular Al( iii )-based complexes have been investigated, and also silanes are known to hydroborate aldehydes (Scheme 1). 16–20…”