Chen Xingyu, Yang Yudong, Han Weiguo, Huang Quan, Huang Zhenmei, You Jingsong
Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China.
Angew Chem Int Ed Engl. 2021 May 25;60(22):12371-12375. doi: 10.1002/anie.202103160. Epub 2021 Apr 23.
The pursuit of efficient synthetic route to thienoacenes represents an appealing yet challenging task in the fields of both organic synthetic chemistry and organic functional materials. In this work, we disclose a rhodium-catalyzed cascade C-H annulation of phenacyl phosphoniums with (benzo)thiophenes via a Heck-type pathway to provide a new class of planar thienoacenes, which involves the formation of three C -C bonds and one C -O bond in a single operation. The neutral S,O-heteroacenes exhibit superior stability and adopt a herringbone-like packing mode with efficient π-π stacking in the crystals, suggesting their potential in organic semiconducting materials. This work first exemplifies the superiority of cascade oxidative C-H annulation involving a Heck-type pathway in the development of concise access to heteroacenes.
