Expanding the scope of atropisomeric monodentate P-Donor ligans in asymmetric catalysis: hydrogen transfer reduction and hydrogenation of alpha,beta-unsaturated Acids Derivatives by Rhodium/Ph-binepine Catalysts

Cationic complexes of rhodium with binaphthophosphepine 1 (Ph-BINEPINE), an axially chiral binaphtalene-core monodentate P-donor ligand (Figure 1), [Rh(nbd)((S)- (Ph-BINEPINE))2]+X-, where X-= BF4-, CF3SO3-and BarF-, have been prepared. These complexes have been tested as catalyst precursors in the asymmetric reduction of α,β- unsaturated acid derivatives by both molecular hydrogen and formic acid as a hydrogen donor source.