Synthesis of a C2-Symmetric Chiral Borinic Acid and Its Application in Catalytic Desymmetrization of 2,2-Disubstituted-1,3-Propanediols

Notwithstanding the common use of boronic acids in catalysis, the design and synthesis of efficient chiral boronic acids remains a formidable challenge. Herein we disclose a rational design and a concise synthesis of a series of novel C2-symmetric disubstituted boronic acids, or borinic acids. Chiral borinic acids have been found to be excellent agents that can achieve highly enantioselective desymmetrization of 2,2-disubstituted-1,3-propanediols, providing chiral diols with a quaternary stereocenter, which has been regarded in recent years as challenging. A wide range of substrates are tolerated in this reaction, providing a series of chiral diols with high enantioselectivity. The presence of the tetracoordinate borinate in the catalytic cycle has been proven by 11B NMR studies, and a stereocontrol model has been proposed.

Automated summary

Despite the widespread use of boronic acids in catalysis, the development of efficient chiral boronic acids remains challenging. In this study, a rational design and a concise synthesis of new C2-symmetric disubstituted boronic acids, or borinic acids, were disclosed. These chiral borinic acids were found to be effective in achieving highly enantioselective desymmetrization of 2,2-disubstituted-1,3-propanediols, leading to chiral diols with a quaternary stereocenter. A range of substrates were successfully utilized in this reaction, providing chiral diols with high enantioselectivity. 11B NMR studies confirmed the presence of tetracoordinate borinate in the catalytic cycle, and a stereocontrol model was proposed.