Deoxygenation of Epoxides with Carbon Monoxide.

Deoxygenation of Epoxides with Carbon Monoxide. Chemistry. 2020 Jun 02;: Authors: Maulbetsch T, Jürgens E, Kunz D Abstract The use of carbon monoxide as a direct reducing agent for the deoxygenation of terminal and internal epoxides to the respective olefins is presented. This reaction is homogeneously catalyzed by a carbonyl pincer-iridium(I) complex in combination with a Lewis acid co-catalyst to achieve a pre-activation of the epoxide substrate as well as the elimination of CO 2 from a γ-2-iridabutyrolactone intermediate. Especially terminal alkyl epoxides react smoothly and without significant isomerization to the internal olefins under CO atmosphere in benzene or toluene at 80-120 °C. Detailed investigations reveal a substrate-dependent change in the mechanism for the epoxide C-O bond activation between an oxidative addition under retention of the configuration and an S N 2 reaction that leads to an inversion of the configuration. PMID: 32484953 [PubMed - as supplied by publisher]
Source: Chemistry - Category: Chemistry Authors: Tags: Chemistry Source Type: research