Reduction of Activated Alkenes by P^III/P^V Redox Cycling Catalysis.

Longwitz, Lars; Werner, Thomas

The carbon–carbon double bond of unsaturated carbonyl compounds was readily reduced by using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl‐substituted phosphetane oxide was employed as the catalyst. The procedure is highly selective towards activated double bonds, tolerating a variety of functional groups that are usually prone to reduction. In total, 25 alkenes and two alkynes were hydrogenated to the corresponding alkanes in excellent yields of up to 99 %. Notably, less active poly(methylhydrosiloxane) could also be utilized as the terminal reductant. Mechanistic investigations revealed the phosphane as the catalyst resting state and a protonation/deprotonation sequence as the crucial step in the catalytic cycle.

CATALYSIS; ALKENES; CARBON-carbon bonds; DOUBLE bonds; UNSATURATED compounds; CYCLING competitions

Angewandte Chemie, 2020, Vol 132, Issue 7, p2782

0044-8249

Academic Journal

10.1002/ange.201912991