New Route for Synthesis of MeO-MOP

Abstract

The axially chiral monophosphine 2-(diphenylphosphino)-2′-methoxy-1,1′-binaphthyl (MeO-MOP) is a versatile ligand. We report a shorter (four steps from chiral BINOL), more atom-economical synthetic route to MeO-MOP. (R)-BINOL is transformed into its monomethyl ether by the Mitsunobu reaction, and the latter is reacted with triflic anhydride to give its triflate. The C-P coupling of the triflate and diphenylphosphine oxide catalyzed by palladium give a phosphine oxide, the precursor of (R)-MeO-MOP, which is reduced with trichlorosilane to furnish (R)-MeO-MOP.

Keywords:

• Chiral monophosphine ligand
• 2-(diphenylphosphino)-2′-methoxy-1,1′-binaphthyl (MeO-MOP)
• 2-diphenylphosphinyl-2′-methoxy-1,1′-binaphthyl
• 2′-methoxy-l,1′-binaphthy 1-2-ol
• 1-(2-methoxynaphthalen-1-yl)naphthalen-2-yl trifluoromethanesulfonate

ACKNOWLEDGMENTS

We thank the National Science Foundation of China (Grant No. 20672088), the Science and Technology Bureau of Sichuan (Grant No. 2011HH0016), and Cultivating Programme for Excellent Innovation Team of Chengdu University of Technology (No. HY0084) for financial support.