Synthesis of aryl group-modified DIOP dioxides (Ar-DIOPOs) and their application as modular Lewis base catalysts?

Organic & Biomolecular Chemistry Pub Date: 2012-04-17 DOI: 10.1039/C2OB25338K

Abstract

Treatment of an optically pure tartaric acid-derived diiodide and various secondary phosphine oxides with LHMDS provides the corresponding aryl group-modified DIOP dioxides (Ar-DIOPOs). The activities of Ar-DIOPOs as Lewis base catalysts were investigated for several asymmetric transformations using chlorosilane reagents. The p-tolyl-substituted DIOPO (p-tolyl-DIOPO) was most effective for the reductive aldol reaction of chalcone and aldehydes with trichlorosilane, whereas the 2,8-dimethylphenoxaphosphine-derived DIOPO (DMPP-DIOPO) afforded the best enantioselectivity for the phosphonylation of conjugated aldehydes and the chlorinative aldol reaction of an ynone and benzaldehyde.

Graphical abstract: Synthesis of aryl group-modified DIOP dioxides (Ar-DIOPOs) and their application as modular Lewis base catalysts
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