Copper(I)-Catalyzed Enantioselective Boryl Substitution of Allyl Acylals: An Efficient Approach for Enantioenriched α-Chiral γ-Acetoxyallylboronates

A novel approach has been developed for the enantioselective synthesis of α-chiral γ-acetoxyallylboronates via the copper(I)-catalyzed γ-boryl substitution of allyl acylals. This reaction proceeded with high E / Z selectivity and enantioselectivity ( E / Z = >99:1, up to 80% yield, up to 99% ee). The subsequent allylation of aldehyde with the allylboronate afforded the monoprotected anti -1,2-diol derivative with high stereoselectivity.