Cu-catalysed asymmetric 1,4-addition of Me3Al to nitroalkenes. Synthesis of (+)-ibuprofen
摘要:
Trimethylaluminium undergoes enantioselective (ee up to 93%) copper-catalysed Michael addition to various nitroalkenes. Copper thiophenecarboxylate (CuTC) (2 mol %) and 4 mol% of a chiral phosphoramidite ligand are sufficient for a complete and clean reaction. The synthesis of (+)-ibuprofen is described with 82% ee. (C) 2005 Elsevier Ltd. All rights reserved.
Cu-catalysed asymmetric 1,4-addition of Me3Al to nitroalkenes. Synthesis of (+)-ibuprofen
摘要:
Trimethylaluminium undergoes enantioselective (ee up to 93%) copper-catalysed Michael addition to various nitroalkenes. Copper thiophenecarboxylate (CuTC) (2 mol %) and 4 mol% of a chiral phosphoramidite ligand are sufficient for a complete and clean reaction. The synthesis of (+)-ibuprofen is described with 82% ee. (C) 2005 Elsevier Ltd. All rights reserved.
Crystallization-Enabled Stereoconvergent Michael Additions of β-Keto Esters to Nitroolefins
作者:Emily R. Sherman、William R. Cassels、Jeffrey S. Johnson
DOI:10.1021/acs.orglett.3c02799
日期:2023.9.15
nucleophiles, the successful use of configurationally unstable β-ketoesters in diastereoselective variants remains understudied. In this Letter, crystalline β-ketoesters were leveraged in a two-phase, one-pot merger of an asymmetric Michael addition with a crystallization-induced diastereomer transformation. Tuning the crystallinity of β-ketoester adducts enabled stereoconvergence of the products, which