Li + ‐Mediated BC Cross‐Coupling

Easy as A, BC : BC cross‐coupling on [3,3′‐Co(8‐I‐1,2‐C 2 B 9 H 10 )(1′,2′‐C 2 B 9 H 11 )] − , [ 1 ] − , the best specimen of metallacarboranes, is easily produced in a reaction mediated by Li + in the absence of a transition‐metal catalyst (see figure). Pure RLi or a mixture of Li reagents ( t BuLi+RLi) is adequate to produce the BC bond. Notably, a threshold of RLi (or t BuLi+RLi)/[ 1 ] − , 2:1, is required to initiate the BC coupling, which acts, at least in part, as a source of soluble Li + .