Diastereoselective Intramolecular Aldol-Type Trapping of Zwitterionic Intermediates by Ketones for the Synthesis of Spiro[chroman-4,3'-oxindole] Derivatives

作者：Jia, Shikun; Lei, Yubing; Song, Longlong; Reddy, A. Gopi Krishna; Xing, Dong; Hu, Wenhao^*

来源：Advanced Synthesis & Catalysis, 2017, 359(1): 58-63.

DOI：10.1002/adsc.201600998

• aromatic C-H functionalization
• rhodium
• spiro[chroman-4,3'-oxindole]derivatives
• trapping
• zwitterionic intermediates

A simple, mild and efficient rhodium-catalyzed aromatic C-H functionalization of alpha-phenoxy ketones by 3-diazooxindoles for the synthesis of the spiro[chroman-4,3'-oxindole] ring system is described. A series of functionalized spiro[chroman-4,3'-oxindole] derivatives bearing two adjacent quaternary carbon centers have been attained in a highly diastereoselective manner with very good yields. Control experiments suggested the possibility of an intramolecular aldol-type trapping of zwitterionic intermediates after the C-H functionalization. Furthermore, the applicability of this method has been tested by a gram-scale synthesis. A facile treatment with base enabled the access to both synand anti-diastereomers via isomerization.

• 出版日期2017-1
• 单位华东师范大学