Enantioenriched Alkylboron Synthesis Via a Chiral Diborylalkane Platform.

Developing new reagents is one efficient strategy for expanding accessible chemical space. Recently, gem-diborylalkanes have emerged as a versatile class of boron-containing reagents with broad reactivity. However, most gem-diborylalkanes are achiral due to the pair of identical boryl groups, which restricts their utility in synthesis, especially for the production of enantioenriched products. To date, only a handful of chiral analogues have been reported, with constricted structural diversity and limited stereospecific transformations. Here, we report the design of a new class of chiral gem-diborylalkane (CDBA) reagents, featuring two boryl groups with chemically distinguishable reactivities, enabling highly selective and stepwise derivatizations. Their versatility is demonstrated through diverse downstream transformations, including the construction of boron stereogenic centers, the synthesis of boron-containing pharmaceuticals, and the preparation of key intermediates for small molecule drugs. These methods offer a powerful platform for the synthesis of enantioenriched alkylboron compounds and hold potential for enhancing synthetic capabilities in drug discovery and development.