New Formamide Catalyst for Ketone Reductions with Trichlorosilane

Significance

Various arylketones 2 could be reduced with trichlorosilane in the presence of a catalytic amount of formamide 1. The enantiomerically enriched alcohols 3 were generated in good yields (61-94%) and excellent enantiomeric ratios (from 96:4 to >99:1). Other reducable groups were preserved. No decrease in yield and selectivity was observed after five recovering/reusing cycles. Starting from lactone 5, which is produced by the reported method followed by cyclization, several biologically active compounds can be synthesized.