Rh(III)-Catalyzed <i>meta</i>-C–H Olefination Directed by a Nitrile Template
作者:Hua-Jin Xu、Yi Lu、Marcus E. Farmer、Huai-Wei Wang、Dan Zhao、Yan-Shang Kang、Wei-Yin Sun、Jin-Quan Yu
DOI:10.1021/jacs.6b13269
日期:2017.2.15
have been developed; however, extension of this reactivity to remote C-H functionalizations through large-ring rhodacyclic intermediates has yet to be demonstrated. Herein we report the first example of the use of a U-shaped nitrile template to direct Rh(III)-catalyzed remote meta-C-H activation via a postulated 12-membered macrocyclic intermediate. Because the ligands used for Rh(III) catalysts are
meta-C-H olefination, arylation, and acetoxylation of indolines have been developed using nitrile-containing templates. The combination of a monoprotected amino acid ligand and the nitrile template attached at the indolinyl nitrogen via a sulfonamide linkage is crucial for the meta-selective C-H fiunctionalization of electron-rich indolines that are otherwise highly reactive toward electrophilic palladation at the para-positions. A wide range of synthetically important and advanced indoline analogues are selectively functionalized at the meta-positions.