Ate Complexes of Secondary Boronic Esters as Chiral Organometallic-Type Nucleophiles for Asymmetric Synthesis

The addition of an aryllithium reagent to a secondary boronic ester leads to an intermediate boron-ate complex that behaves as a chiral nucleophile, reacting with a broad range of electrophiles with inversion of stereochemistry. Depending on the electrophile, the C–B bond can be converted into C–I, C–Br, C–Cl, C–N, C–O, and C–C, all with very high levels of stereocontrol. This discovery now adds a new, readily available, configurationally stable, chiral organometallic-type reagent to the arsenal of methods for use in asymmetric organic synthesis.