title: A [4+1] Cyclative Capture Approach to 3H-Indole-N-oxides at Room Temperature by Rhodium(III)-Catalyzed CH Activation.
abstract: The rhodium(III)-catalyzed [3+2] CH cyclization of aniline derivatives and internal alkynes represents a useful contribution to straightforward synthesis of indoles. However, there is no report on the more challenging synthesis of pharmaceutically important N-hydroxyindoles and 3H-indole-N-oxides. Reported herein is the first rhodium(III)-catalyzed [4+1] CH oxidative cyclization of nitrones with diazo compounds to access 3H-indole-N-oxides. More significantly, this reaction proceeds at room temperature and has been extended to the synthesis of N-hydroxyindoles and N-hydroxyindolines.
authors.affiliation: Department of Medicinal Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203 (PR China).
authors.forename: Yaxi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Medicinal Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203 (PR China).
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Medicinal Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203 (PR China).
authors.forename: Yuanchao
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Medicinal Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203 (PR China). zhoubing2012@hotmail.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhou
keywords: CH activation; cyclizations; diazo compounds; heterocycles; rhodium