Direct C(sp<sup>2</sup>)-H alkylation of unactivated arenes enabled by photoinduced Pd catalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33077720.
- Also identified by DOI 10.1038/s41467-020-19038-8 and PMC identifier 7572399.
- 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
Despite the fundamental importance of efficient and selective synthesis of widely useful alkylarenes, the direct catalytic C(sp<sup>2</sup>)-H alkylation of unactivated arenes with a readily available alkyl halide remains elusive. Here, we report the catalytic C(sp<sup>2</sup>)-H alkylation reactions of unactivated arenes with alkyl bromides via visible-light induced Pd catalysis. The reaction proceeds smoothly under mild conditions without any skeletal rearrangement of the alkyl groups. The direct syntheses of structurally diverse linear and branched alkylarenes, including the late-stage phenylation of biologically active molecules and an orthogonal one-pot sequential Pd-catalyzed C-C bond-forming reaction, are achieved with exclusive chemoselectivity and exceptional functional group tolerance. Comprehensive mechanistic investigations through a combination of experimental and computational methods reveal a distinguishable Pd(0)/Pd(I) redox catalytic cycle and the origin of the counter-intuitive reactivity differences among alkyl halides.