Catalyst‐Controlled Switch in Chemo‐ and Diastereoselectivities: Annulations of Morita–Baylis–Hillman Carbonates from Isatins. (6th January 2016)

• Record Type: Journal Article
• Authors: Zhan, Gu; Shi, Ming‐Lin; He, Qing; Lin, Wei‐Jia; Ouyang, Qin; Du, Wei; Chen, Ying‐Chun
• Is Part Of: Angewandte Chemie. Volume 128:Number 6(2016)
• Page Start: 2187
• Page End: 2191
• Publication Date: 2016-01-06
• Subjects: Diastereoselektivität -- Dichtefunktionalrechnungen -- Heterocyclen -- Organokatalyse -- Ringschlussreaktionen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201510825
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Regulating both the chemo‐ and diastereoselectivity, divergently, of a reaction is highly attractive but extremely challenging. Presented herein is a catalyst‐controlled switch in the chemo‐ and diastereodivergent annulation reactions of Morita–Baylis–Hillman carbonates, derived from isatins and 2‐alkylidene‐1 H ‐indene‐1, 3(2 H )‐diones, in exclusive α‐regioselectivity. α‐Isocupreine efficiently catalyzed [2+1] reactions to access cyclopropane derivatives, and the diastereodivergent [3+2] annulations were accomplished by employing either a chiral phosphine or a DMAP‐type molecule. All reactions exhibited excellent chemoselectivities, and good to remarkable stereoselectivities were furnished, thus leading to a collection of compounds with skeletal and stereogenic diversity. Moreover, DFT computational calculations elucidated the catalyst‐based switch in mechanism.