Organocatalytic Kinetic Resolution of Racemic Secondary Nitroallylic Alcohols Combined with Simultaneous Desymmetrization of Prochiral Cyclic Anhydrides
摘要:
This study describes an organocatalytic kinetic resolution of racemic secondary nitroallylic alcohols (2) combined with simultaneous desymmetrization of prochiral cyclic anhydrides (1). The experimental results revealed that enantioselective alcoholysis of 3-substituted glutaric anhydrides afforded hemiesters (3) with high levels of enantioselectivities (up to 99% ee) in the presence of cinchonidine-derived thiourea catalyst (IV). The highly optical enrichment (up to 95% ee) of (S)-nitroallylic alcohols (2) was recovered.
An efficient Morita–Baylis–Hillman reaction for the synthesis of multifunctional 2-hydroxy-3-nitrobut-3-enoate derivatives
摘要:
An efficient thiourea promoted MBH reaction of various conjugated nitroalkenes with ethyl glyoxylate was developed. The desired multifunctional products, 2-hydroxy-3-nitro-4-aryl/alkylbut-3-enoate derivatives were obtained in good to high chemical yields (56-92%) with DMAP (20 mol%) under solvent-free conditions or imidazole (100 mol%) in the presence of water. (C) 2010 Elsevier Ltd. All rights reserved.
This study describes an organocatalytic kinetic resolution of racemic secondary nitroallylic alcohols (2) combined with simultaneous desymmetrization of prochiral cyclic anhydrides (1). The experimental results revealed that enantioselective alcoholysis of 3-substituted glutaric anhydrides afforded hemiesters (3) with high levels of enantioselectivities (up to 99% ee) in the presence of cinchonidine-derived thiourea catalyst (IV). The highly optical enrichment (up to 95% ee) of (S)-nitroallylic alcohols (2) was recovered.
An efficient Morita–Baylis–Hillman reaction for the synthesis of multifunctional 2-hydroxy-3-nitrobut-3-enoate derivatives
作者:Hsuan-Hao Kuan、Raju Jannapu Reddy、Kwunmin Chen
DOI:10.1016/j.tet.2010.10.061
日期:2010.12
An efficient thiourea promoted MBH reaction of various conjugated nitroalkenes with ethyl glyoxylate was developed. The desired multifunctional products, 2-hydroxy-3-nitro-4-aryl/alkylbut-3-enoate derivatives were obtained in good to high chemical yields (56-92%) with DMAP (20 mol%) under solvent-free conditions or imidazole (100 mol%) in the presence of water. (C) 2010 Elsevier Ltd. All rights reserved.