Stereoselective Synthesis of Unsymmetrical 1,1-Diborylalkenes

1,1-Diborylalkene, a class of important diboryl species, serves as the synthetic precursor of multisubstituted olefin, which is a prevalent building block in natural products, functional materials, and pharmaceuticals. Current methods mainly afford symmetrical 1,1-diborylalkenes, and late-stage differentiation of the two identical boryl groups is required to achieve selective difunctionalization. In comparison, stereoselective synthesis of unsymmetrical 1,1-diborylalkenes (UDBA) are less-explored. This Synpacts article provides a brief summary of the achievements in the synthesis of UDBAs. In particularly, we highlight our recent work on the unsymmetrical 1,1-diborylation of alkynes using a neutral sp2–sp3 diboron reagent to access UDBAs and their controllable stepwise derivatization.1 Introduction2 Background: Unsymmetrical 1,1-Diborylalkene Synthesis3 Stereoselective Unsymmetrical 1,1-Diborylation of Alkynes with a Neutral sp2–sp3 Diboron Reagent4 Summary and Outlook