Experimental transition state for the Corey–Bakshi–Shibata reduction

Asymmetric reductions of prochiral ketones are important transformations in the syntheses of natural products, pharmaceuticals, and fine chemicals. The Corey–Bakshi–Shibata reduction is unique among hydride transfer reductions in its tremendous substrate range and catalytic nature. Here, a coordinated computational and experimental approach is taken toward understanding the origins of the high selectivity and broad substrate range, which are hallmarks of this reduction.