Efficient microwave-assisted formation of functionalized 2,5-dihydropyrroles using ruthenium-catalyzed ring-closing metathesis
摘要:
A rapid method for the formation of functionalized 2,5-dihydropyrroles using ruthenium-catalyzed ring-closing metathesis under microwave irradiation is presented. The diene substrates were efficiently prepared from aza-Baylis-Hillman adducts. (C) 2004 Elsevier Ltd. All rights reserved.
Highly Enantioselective Aza-Baylis-Hillman Reactions Catalyzed by Chiral Thiourea Derivatives
作者:Izzat T. Raheem、Eric N. Jacobsen
DOI:10.1002/adsc.200505230
日期:2005.10
aza-Baylis–Hillman (ABH) reactions of N-p-nitrobenzenesulfonylimines with methyl acrylate catalyzed by chiral thiourea derivatives. A series of aromatic imines was found to undergo coupling with methyl acrylate with unprecedented levels of enantioselectivity (87–99% ee), albeit only in modest (25–49%) yields. A DABCO-acrylate-imine adduct was isolated as a key intermediate in the ABH reaction. We provide a mechanistic