Stereochemistry of Imine Reduction by a Hydroxycyclopentadienyl Ruthenium Hydride

摘要

The stereochemistry of hydrogen transfer from [2,5-Ph_2-3,4-Tol_2(eta~5-C_4COD)]Ru(CO)_2D to N-aryl imines to give amine complexes was shown to be mostly trans stereospecific.Stereospecific hydrogen transfer is proposed to generate an amine and a coordinatively unsaturated ruthenium intermediate in close proximity.Coordination of the amine is proposed to occur faster than lone pair inversion of the amine.In contrast,hydrogen transfer to N-alkyl imines is stereorandom.It is proposed that stereochemistry is lost in part due to the reversibility of the hydrogen transfer being faster than amine coordination.