Regioselective Transfer Hydrodeuteration of Alkenes with a Hydrogen Deuteride Surrogate Using B(C6F5)3 Catalysis

A regioselective hydrodeuteration of alkenes using monodeuterated cyclohexa-1,4-dienes as surrogates for hydrogen deuteride (HD) gas is reported. The metal-free process proceeds under B(C6F5)3 catalysis presumably by deuteride abstraction to form borodeuteride [DB(C6F5)3]− and highly Brønsted-acidic Wheland intermediates. Low catalyst loadings (2.5 mol %) are used, and the reaction proceeds at room temperature.