Zhong Xiuhua, Lin Shuang, Gao Hui, Liu Fu-Xiaomin, Zhou Zhi, Yi Wei
Key Laboratory of Molecular Target & Clinical Pharmacology and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences & The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 511436, China.
Org Lett. 2021 Mar 19;23(6):2285-2291. doi: 10.1021/acs.orglett.1c00418. Epub 2021 Mar 3.
An efficient and redox-neutral Rh(III)-catalyzed C-H activation/[3 + 2] annulation of -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 S2'-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.
实现了一种高效且氧化还原中性的铑（III）催化的苯氧基酰胺与炔丙基单氟炔烃的C-H活化/[3 + 2]环化反应，以得到具有有趣的α-季碳中心的3-亚烷基二氢苯并呋喃。结合实验和计算机理研究表明，催化循环中可能涉及铑（III）-铑（V）-铑（III）催化途径/未催化的分子内[H···F]键辅助的S2'-型取代级联反应，从而实现了优异的位点/区域选择性以及广泛的底物/官能团兼容性，包括在3-位完全保留高度应变的环丁基结构。
