We report herein the room temperature insertion of the carbene carbon atom of the cyclic (alkyl)(amino) carbene cAACMe into the B–B single bonds of the diboron(4) compounds B2pin2, B2cat2, B2neop2, and B2eg2 (pin = pinacolato, cat = catecholato, neop = neopentylglycolato, eg = ethyleneglycolato).
