Asymmetric [4 + 3] Annulations for Constructing Divergent Oxepane Frameworks via Cooperative Tertiary
Zhi Chen1, Zhi-Chao Chen1, Wei Du1
1Key Laboratory of Drug-Targeting and Drug Delivery System of the Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Abstract:
We report asymmetric [4 + 3] annulations between isatin-derived Morita-Baylis-Hillman carbonates and two types of vinyl carbonates synergistically catalyzed by tertiary amines and transition metals, through chemoselective assemblies of in situ formed allylic ylides and metal-containing 1,4-dipoles. A range of oxepane frameworks are generally constructed in moderate to good yields with high stereocontrol. Moreover, all four diastereomers for the products bearing vicinal stereocenters are accessible by tuning tertiary amine and metal catalysts.
Related Concept Videos
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation


![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)