Alpha-methylene-beta-amino ketone derivatives from beta-ketoallylsilanes
M Antonietta Loreto1, Antonella Migliorini, P Antonio Tardella
1Dipartimento di Chimica, Università La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy. mariaantonietta.loreto@uniroma1.it
Abstract:
Beta-Ketoallylsilanes are synthesized by the Horner-Emmons reaction starting from novel silylated ketophosphonates and various aldehydes. The reactions of beta-ketoallylsilanes with NsONHCO2Et and CaO produce alpha-methylene-N-(ethoxycarbonyl)-beta-amino ketones through the ring opening of the intermediate aziridine, which is favored by the presence of the trimethylsilyl group. With chiral beta-ketoallylsilanes we obtained a stereoselective amination reaction with a 90% diastereomeric excess. alpha-Methylene-N-(ethoxycarbonyl)-beta-amino ketones are isolated in 39-60% yields and characterized.
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