The direct, site-selective alkylation of unactivated C(sp3)-H bonds in organic substrates is a long-standing goal in synthetic chemistry. General approaches to the activation of strong C-H bonds include radical-mediated processes involving highly reactive intermediates, such as heteroatom-centered radicals. Herein, we describe a catalytic, intermolecular C-H alkylation that circumvents such reactive species via a new elementary step for C-H cleavage involving multisite-proton-coupled electron transfer (multisite-PCET). Mechanistic studies indicate that the reaction is catalyzed by a noncovalent complex formed between an iridium(III) photocatalyst and a monobasic phosphate base. The C-H alkylation proceeds efficiently using diverse hydrocarbons and complex molecules as the limiting reagent and represents a new approach to the catalytic functionalization of unactivated C(sp3)-H bonds.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of the American Chemical Society|
|State||Published - Aug 21 2019|
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry