Enantioselective copper-catalyzed B-H bond insertion reaction of α-diazo phosphonates to access chiral α-boryl phosphonates.

Chiral phosphorus-containing compounds find applications across various fields, including asymmetric catalysis, medicinal chemistry, and materials science. Despite the abundance of reported highly enantioselective methods for synthesizing various chiral phosphorus compounds, the enantioselective synthesis of α-boryl phosphorus compounds still remains an unknown territory. Here, we report a method for the construction of chiral α-boryl phosphates by asymmetric B-H insertion reaction using α-diazo phosphates as carbene precursors, cheap and readily available copper salt as the catalyst and chiral oxazoline as the ligand. This method can directly afford a series of stable α-boryl phosphates with a yield up to 97% and an enantioselectivity up to 98% ee. The operating procedure of this method is straightforward, offering a broad substrate applicability, remarkable tolerance towards various functional groups, and gentle reaction conditions.