Stereoselective alkoxycarbonylation of unactivated C(sp3)-H bonds with alkyl chloroformates via Pd(II)/Pd(IV) catalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27678161.
- Also identified by DOI 10.1038/ncomms12901 and PMC identifier 5052708.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Several examples on Pd-catalysed carbonylation of methyl C(sp<sup>3</sup>)-H bonds with gaseous CO via Pd(II)/Pd(0) catalysis have been reported. However, methylene C(sp<sup>3</sup>)-H carbonylation remains a great challenge, largely due to the lack of reactivity of C-H bonds and the difficulty in CO migratory insertion. Herein, we report the stereoselective alkoxycarbonylation of both methyl and methylene C(sp<sup>3</sup>)-H bonds with alkyl chloroformates through a Pd(II)/Pd(IV) catalytic cycle. A broad range of aliphatic carboxamides and alkyl chloroformates are compatible with this protocol. In addition, this process is scalable and the directing group could be easily removed under mild conditions with complete retention of configuration.