Phosphine-catalyzed activation of cyclopropenones: a versatile C3 synthon for (3+2) annulations with unsaturated electrophiles
Chemical Science2022Vol. 13(43), pp. 12769–12775
Citations Over TimeTop 10% of 2022 papers
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.
Related Papers
- → Ylide formal [4 + 1] annulation(2015)104 cited
- → Synthesis of Tetrahydro-2H-thiopyran 1,1-Dioxides via [1+1+1+1+1+1] Annulation: An Unconventional Usage of a Tethered C–S Synthon(2022)23 cited
- → Construction of C2‐Spirocyclopropyl‐Indolin‐3‐Ones through Base‐Promoted [2+1] Annulation Reaction of Indolin‐3‐ones with Bromosulfonium Salts(2023)10 cited
- → Anomalous Epoxide Formation Upon Wittig Olefination With 1-Iodoethyl Triphenylphosphonium Ylide(1998)25 cited