An Ab Initio Investigation of the RhI‐Catalyzed Hydroboration of CC Bonds: Evidence for Hydrogen Migration in the Key Step

Participation of several 14-electron complexes as intermediates in the Rh(PH3)3Cl-catalyzed addition of BH3 to alkenes is suggested by results of ab initio pseudopotential computations, which also indicate a preference for migration of a hydrogen atom rather than the BH2 group to the C  C bond in the key step. The calculations also provide a rationale for the diastereoselectivity of the reaction. The structure calculated for one of the intermediates is shown on the right.