Tert-butylamine-catalyzed free radical annulations with cyclic diaryliodoniums occur in environmentally friendly ethyl acetate and do not require transition metal, providing diversified polycyclic aromatic hydrocarbons by modulating substituents.
We report here a two-in-one strategy for the Pd(II)-catalyzed tandem C–H arylation/decarboxylative annulation between readily available cyclic diaryliodoniumsalts and benzoic acids. The carboxylic acid functionality can be used as both a directing group for the ortho-C–H arylation and the reactive group for the tandem decarboxylative annulation. By a step-economical double cross-coupling annulation
Pd-catalyzed C-H annulation reactions of halo- and aryl-heteroarenes were developed using readily available o-bromobiaryls and o-dibromoaryls, respectively. A variety of five-membered heteroarenes rapidly provided the corresponding phenanthrene-fused heteroarenes, which led to the identification of phenanthro-pyrazole and thiazole as new, stable -2 V redox couples. The flexible syntheses and tunability
Palladium-Catalyzed Synthesis of Triphenylenes via Sequential C–H Activation and Decarboxylation
作者:Yuzhong Yang、Bang Zhou、Xiaoming Zhu、Guobo Deng、Yun Liang、Yuan Yang
DOI:10.1021/acs.orglett.8b02310
日期:2018.9.7
A novel tandem intermolecular decarboxylative coupling reaction of o-bromobenzoic acids and aryl iodides has been developed. The method affords a range of unsymmetrically triphenylenes and displays unique regioselectivity and broad substrate scope. Mechanistically, palladium/norbornene-catalyzed C–H activation and subsequent double decarboxylative coupling reactions were involved. Moreover, the triphenylenes