Temperature-Dependent Direct Enantioconvergent Silylation of a Racemic Cyclic Allylic Phosphate by Copper(I)-Catalyzed Allylic Substitution

Abstract

The near-quantitative transformation of a racemic cyclic allylic phosphate to a highly enantiomerically enriched allylic silane by allylic substitution with a silicon nucleophile is reported. The reaction is catalyzed by a chiral NHC–copper(I) complex. Experimental analysis revealed a rare case of a direct enantioconvergent transformation where the enantiomeric allylic phosphates converge to the same allylic silane by two distinctive S_N2′ pathways with opposite diastereofacial selectivity.

Key words

allylic substitution - copper - enantioselectivity - N-heterocyclic carbenes - silicon

• References

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