Anti-Markovnikov alcohols via epoxide hydrogenation through cooperative catalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31123133.
- Also identified by DOI 10.1126/science.aaw3913.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The opening of epoxides typically requires electrophilic activation, and subsequent nucleophilic (S<sub>N</sub>2) attack on the less substituted carbon leads to alcohols with Markovnikov regioselectivity. We describe a cooperative catalysis approach to anti-Markovnikov alcohols by combining titanocene-catalyzed epoxide opening with chromium-catalyzed hydrogen activation and radical reduction. The titanocene enforces the anti-Markovnikov regioselectivity by forming the more highly substituted radical. The chromium catalyst sequentially transfers a hydrogen atom, proton, and electron from molecular hydrogen, avoiding a hydride transfer to the undesired site and resulting in 100% atom economy. Each step of the interconnected catalytic cycles was confirmed separately.