Aromatic C-H addition of ketones to imines enabled by manganese catalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29079807.
- Also identified by DOI 10.1038/s41467-017-01262-4 and PMC identifier 5660118.
- 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
Selectivity control of varied C-H bonds in a complex molecule is a long-standing goal and still a great challenge in C-H activation field. Most often, such selectivity is achieved by the innate reactivity of different C-H bonds. In this context, the classic Mannich reaction of acetophenone derivatives and imines is ascribed to the more reactive C(sp<sup>3</sup>)-H bonds α to the carbonyl, with the much less reactive aromatic C(sp<sup>2</sup>)-H bonds remaining intact. Herein we report an aromatic C(sp<sup>2</sup>)-H addition of ketones to imines enabled by manganese catalysis, which totally reverses the innate reactivity of C-H bonds α to the carbonyl and those on the aromatic ring. Diverse products of ortho-C-H aminoalkylated ketones, cyclized exo-olefinic isoindolines, and three-component methylated isoindolines can be successfully accessed under mild reaction conditions, which significantly expands the synthetic utilities of ketones as simple bulk chemicals.