The application of three types of chiral spiro monophosphorus ligands in rhodium-catalyzed asymmetric hydroformylation was investigated.The chiral spiro phosphoramidite ligands(SIPHOS)were found to be efficient in this reaction,and the alkyl groups on the amino moiety of SIPHOS ligands played a critical role in the control of regio-selectivity and enantioselectivity of the reaction,with i-Pr being the best choice.Under the optimized reaction conditions,styrene and its derivatives could successfully react as substrates in excellent yields and regio-selectivities,and modest level of enantioselctivities.
