Rhodium-BisbenzodioxanPhos complex-catalyzed homogeneous enantioselective Pauson-Khand-type cyclization in alcoholic solvents

The chiral atropisomeric diphosphane ligand (S)-BisbenzodioxanPhos was found to be highly effective in the co-operative processeses of aldehyde decarbonylation and cascaded enantioselective Pauson-Khand-type reactions. Various 1,6-enynes were transformed to the corresponding bicyclic cyclopentenones in good yields and enantiomeric excesses (up to 96% ee). The attractive feature of this new Rh-catalyzed homogeneous dual catalysis system is that the reaction can be performed in alcoholic solution.