Reductive cleavage of the Csp2-Csp3 bond of secondary benzyl alcohols: rhodium catalysis directed by N-containing groups.

Cutting loose: 1,1-Biarylmethanol substrates undergo reductive cleavage of the C-C bond in the presence of a cationic Rh(III) catalyst and H(2) (see scheme; DG=directing group). Various functional groups are tolerated in the reaction system. Preliminary studies indicate that a five-membered rhodacycle intermediate, which then converts into a Rh(III) hydride species for the reduction, is involved in the catalytic cycle.