Dual-organocatalytic Michael/Michael/aldol cascade reaction for the asymmetric construction of fully-substituted cyclohexane. Issue 51 (21st December 2016)

• Record Type: Journal Article
• Authors: Sun, Qiang-Sheng; Zhu, Hua; Lin, Hua; Tan, Yu; Yang, Xiao-Di; Sun, Xing-Wen; Sun, Xun
• Is Part Of: Tetrahedron letters. Volume 57:Issue 51(2016)
• Page Start: 5768
• Page End: 5770
• Publication Date: 2016-12-21
• Subjects: Cascade reaction -- Organocatalysis -- Fully-substituted cyclohexane -- Multicomponets reaction -- Squaramide catalyst; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2016.11.033
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Enatiopure fully-substituted cyclohexanes bearing six stereocenters were synthesized. Low loading dual-organocatalysts were used. Excellent stereoselectivities (>99% ee, >20:1 dr in all cases) were obtained. Abstract: An efficient cascade reaction was developed affording fully-substituted cyclohexane bearing six contiguous stereocenters via Michael/Michael/aldol sequence. This reaction was catalyzed by low loading of dual-organocatalyst, H-bond donor squaramide (0.5 mol%) and achiral secondary amine pyrrolidine (10 mol%). Good yields (up to 81%), excellent diastereoselectivities (>20:1 in all cases) and enantioselectivities (>99% in all cases) were obtained for a wide array of Michael acceptors.