Selective B–B bond activation in an unsymmetrical diborane(4) by [(Me3P)4Rh–X] (X = Me, OtBu): a switch of mechanism?†
Abstract
The unsymmetrical diborane(4) pinB–B((RN)2(C6H4)) (R = Me, Bn) reacts with [(Me3P)4Rh–X] (X = Me, OtBu) giving predominantly either [(Me3P)4Rh–Bpin] or [(Me3P)3Rh–B((RN)2(C6H4))] depending on X. At low temperatures in the presence of excess PMe3 the unprecedented equatorial boryl complex [(Me3P)4Rh–B((MeN)2(C6H4))] is formed.