Rh(III)-Catalyzed Redox-Neutral C–H Activation/[3 + 2] Annulation of <i>N</i>-Phenoxy Amides with Propargylic Monofluoroalkynes
Xiuhua Zhong, Shuang Lin, Hui Gao, Fu‐Xiaomin Liu, Zhi Zhou, Wei Yi
Abstract
An efficient and redox-neutral Rh(III)-catalyzed C–H activation/[3 + 2] annulation of N-phenoxy amides with propargylic monofluoroalkynes has been realized to afford 3-alkylidene dihydrobenzofurans with an interesting α-quaternary carbon center. Combined experimental and computational mechanistic studies revealed that a Rh(III)–Rh(V)–Rh(III) catalytic pathway/uncatalyzed intramolecular [H···F] bonding-assisted SN2′-type substitution cascade might be involved in the catalytic cycle, thereby enabling an excellent site-/regioselectivity with broad substrate/functional group compatibility, including the complete retention of the highly strained cyclobutyl structure in the 3-position.