Enantioselective intermolecular all-carbon [4+2] annulation via N-heterocyclic carbene organocatalysis. Issue 100 (30th November 2017)

• Record Type: Journal Article
• Authors: Zhang, Guoxiang; Xu, Weici; Liu, Jian; Das, Deb Kumar; Yang, Shuang; Perveen, Saima; Zhang, Hao; Li, Xinglong; Fang, Xinqiang
• Is Part Of: Chemical communications. Volume 53:Issue 100(2017)
• Page Start: 13336
• Page End: 13339
• Publication Date: 2017-11-30
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c7cc08680f
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : The challenge of asymmetric intermolecular all-carbon [4+2] annulation via α, β-unsaturated acyl azoliums was addressed with 2-acyloxy-3-butenones as suitable dienolate precursors, and a variety of highly functionalized cyclohexene products were delivered at a high level of enantioselectivity. Abstract : The highly stereoselective intermolecular all-carbon [4+2] annulation between in situ generated acyclic dienolates and α, β-unsaturated acyl azoliums is disclosed. The identification of 2-acyloxy-3-butenones as suitable diene precursors is the key to the success of this transformation. The corresponding highly functionalized cyclohexene products, which are inaccessible from Diels–Alder reactions, were delivered with high levels of diastereo- and enantioselectivities. A series of further transformations based on the product showed the potential of this reaction.