Copper-Catalyzed Regio-, Diastereo-, and Enantioselective Allylic Alkylation with 1,1-Diborylalkanes.

We report a copper-catalyzed regio-, diastereo-, and enantioselective allylic alkylation of allyl bromides using 1,1-diborylalkanes as prochiral nucleophiles. This methodology employs copper(I) bromide as a catalyst, an ()-BINOL-derived phosphoramidite as a ligand, and lithium benzoate as a crucial additive. The reaction affords enantioenriched homoallylic boronic esters possessing vicinal stereocenters in good yields and high diastereo- and enantioselectivity.

Anion-Mediated, Stereospecific Synthesis of Secondary and Tertiary Cyclopropylboronates from Chiral Epoxides and -Diborylalkanes.

We report a transition-metal-free deborylative cyclization approach to synthesize enantioenriched secondary and tertiary cyclopropylboronates using γ-phosphate-containing -diborylalkanes derived from chiral epoxides and -diborylalkanes. Our method enables the synthesis of a broad range of enantioenriched secondary and tertiary cyclopropylboronates in good yields with excellent stereospecificity. We demonstrate the versatility of our approach by performing a gram-scale reaction.