Phosphine-catalyzed activation of cyclopropenones: a versatile C3 synthon for (3+2) annulations with unsaturated electrophiles. Issue 43 (24th October 2022)

• Record Type: Journal Article
• Authors: He, Xin; Ma, Pengchen; Tang, Yuhai; Li, Jing; Shen, Shenyu; Lear, Martin J.; Houk, K. N.; Xu, Silong
• Is Part Of: Chemical science. Volume 13:Issue 43(2022)
• Page Start: 12769
• Page End: 12775
• Publication Date: 2022-10-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2sc04092a
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : A phosphine-catalyzed (3 + 2) annulation of cyclopropenones with a wide variety of electrophilic π systems has been developed, in which an α-ketenyl phosphorous ylide is validated as the key intermediate used as a versatile C3 synthon. Abstract : We herein report a phosphine-catalyzed (3 + 2) annulation of cyclopropenones with a wide variety of electrophilic π systems, including aldehydes, ketoesters, imines, isocyanates, and carbodiimides, offering products of butenolides, butyrolactams, maleimides, and iminomaleimides, respectively, in high yields with broad substrate scope. An α-ketenyl phosphorous ylide is validated as the key intermediate, which undergoes preferential catalytic cyclization with aldehydes rather than stoichiometric Wittig olefinations. This phosphine-catalyzed activation of cyclopropenones thus supplies a versatile C3 synthon for formal cycloadditon reactions.