%0 Journal Article
%T Catalyst-Free Regioselective Diborylation of Aryllithium with Tetra(o-tolyl)diborane(4).
%A Mao X
%A Lu Z
%A Zhang J
%A Xie Z
%J Angew Chem Int Ed Engl
%V 63
%N 6
%D 2024 Feb 5
%M 38123525
%F 16.823
%R 10.1002/anie.202317614
%X A catalyst-free 1,2-diborylation of aryllithium with tetra(o-tolyl)diborane(4) has been achieved, giving a series of 1,2-diborylaryl lithium species in excellent yields under mild reaction conditions, which leads to 1,2-di(tolyl)borylarenes in 60-91 % yields upon treatment with the hydride-abstracting reagent. In these transformations, one sp2 C-H of arene is activated and both boryl units are utilized to build two new (sp2 )C-B bonds. This represents a new strategy for selective arene diborylation. Density functional theory (DFT) calculations suggest that an aromatic nucleophilic substitution is a key step in the formation of the products.