p-Selective (sp)-C-H functionalization of electron rich arenes has been achieved for acylation and alkylation reactions, respectively, with acyl/alkylselenides by organic photoredox catalysis involving an interesting mechanistic pathway.
Herein, we report
Fe(III)(TPP)Cl as an effective catalyst
for promoting arene C–H amidation through intramolecular cyclization
of N-tosyloxyarylcarbamate substrates. The reaction
proceeds via nitrene (outer sphere pathway) C(sp2)–H
insertion to yield benzoxazolones under external-oxidant-free conditions
at ambient temperature. The method is operationally simple and scalable
with high-functional-group tolerance. Preliminary experimental and
computational data indicates involvement of electrophilic aromatic
substitution mechanism for this aryl C–H amidation transformation,
distinct from operating mechanism reported previously in aryl C–H
amination using azide-based substrates.
Visible light-mediated photoredox activation of 10-methyl-9,10-dihydroacridine in the presence of electron-deficient alkenes leads to selective g-sp 3 C À H alkylation whereby 4-alkyl-N,N-dimethylA C H T U N G T R E N N U N G anilines produce substituted tetrahydroquinolines by a subsequent alkylation/cyclization sequence involving interesting mechanistic pathways.
α-Arylation of ketones with electron rich arenes via sp2(C)–H has been achieved by the reaction of α-phenylselanylketones using organic photoredox catalysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.