Nickel-catalysed direct alkylation of thiophenes via double C(sp3)-H/C(sp2)-H bond cleavage: the importance of KH2PO4Electronic supplementary information (ESI) available. CCDC 1529734. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7cc04252c

• Main Authors: Wang, Xie, Xie, Peipei, Qiu, Renhua, Zhu, Longzhi, Liu, Ting, Li, You, Iwasaki, Takanori, Au, Chak-Tong, Xu, Xinhua, Xia, Yuanzhi, Yin, Shuang-Feng, Kambe, Nobuaki
• Format: Article
• Language: English
• ISSN: 1359-7345; 1364-548X
• DOI: 10.1039/c7cc04252c

A Ni-catalyzed oxidative C-H/C-H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes. This method employs thiophenes and aliphatic (aromatic) amides that contain an 8-aminoquinoline as a removable directing group in the presence of a silver oxidant. The approach enables the facile one-step synthesis of substituted thiophenes with high functional group compatibility via double C-H bond cleavage without affecting C-Br and C-I bonds. DFT calculations verify the importance of KH 2 PO 4 as an additive for promoting C-H bond cleavage and support the involvement of a Ni( iii ) species in the reaction. A Ni-catalyzed C-H/C-H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes.