A bifunctional squaramide-catalysed enantioselective vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α, α-dicyanoalkenes. Issue 39 (22nd September 2021)

• Record Type: Journal Article
• Authors: Wang, Yu; Niu, Cheng; Xie, Dong-Hua; Du, Da-Ming
• Is Part Of: Organic & biomolecular chemistry. Volume 19:Issue 39(2021)
• Page Start: 8572
• Page End: 8577
• Publication Date: 2021-09-22
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d1ob01256h
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : An effective strategy for the stereoselective synthesis of spiro isoxazolone-cyclohexenimines was developed via a squaramide-catalysed vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α, α-dicyanoalkenes. Abstract : An effective strategy for the stereoselective synthesis of spiro isoxazolone-cyclohexenimines was developed using a bifunctional squaramide-catalysed vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α, α-dicyanoalkenes. The atom-economical cascade process can proceed smoothly under extremely low catalyst loading (1 mol%) and mild conditions, and the corresponding products were obtained in moderate to good yields (45% to 90%) and enantioselectivitites (51% to 96% ee). Meanwhile, the scale-up reaction and transformation of the products were also demonstrated.