Transition-Metal-Free Highly Chemoselective and Stereoselective Reduction with Se/DMF/H 2 O System.

A novel metal-free reduction system, in which H ₂ Se (or HSe ^- ) produced in situ from Se/DMF/H ₂ O acts as the active reducing species, has been developed. By using water as an inexpensive, safe, and environmentally friendly surrogate as the hydrogen donor, this new reduction system incorporating Se/DMF/H ₂ O displayed high selectivity and good activity in the reduction of α,β-unsaturated ketones and alkynes. Therefore, this reduction system has great potential to be a general and practical reduction methodology in organic transformation.