Disulfonimide-Catalyzed Asymmetric Synthesis of δ-Amino-β-Keto Esters
摘要:
A chiral disulfonimide-catalyzed asymmetric synthesis of -amino--keto esters via a vinylogous Mukaiyama-Mannich reaction of the Chan diene with N-Boc imines has been developed. The desired products were obtained in good to excellent yields and enantioselectivities.
Asymmetric phase-transfer catalysis was first applied to the synthesis of chiral N,S-acetals by using amino acid-based bifunctional thiourea-ammonium salt catalysts. The reaction could be performed on the gram scale to give up to 93% ee and 99% yield with a catalyst loading as low as 0.1 mol % within 5 min.
Enantioselective Mannich reaction of γ-malonate-substituted α,β-unsaturated esters with N-Boc imines catalyzed by chiral bifunctional thiourea-phosphonium salts
作者:Jiaxing Zhang、Gang Zhao
DOI:10.1016/j.tet.2018.12.052
日期:2019.3
A novel enantioselective Mannichreaction of γ-malonate-substituted α, β-unsaturated esters with N-protected arylaldimines was realized by using asymmetric phase-transfer catalysis (APTC). With amino acid-derived bifunctional thiourea-phosphonium salts as a catalyst, a series of enantio-enriched Mannich products could be synthesized under very mild and simple reaction conditions with high yields and
Enantioselective Cycloaddition of Styrenes with Aldimines Catalyzed by a Chiral Magnesium Potassium Binaphthyldisulfonate Cluster as a Chiral Brønsted Acid Catalyst
A chiral magnesium potassium binaphthyldisulfonate cluster, as a chiral Brønsted acid catalyst, was shown to catalyze an enantioselective cycloaddition of styrenes with aldimines for the first time. The strong Brønsted acidity of the catalyst precursors, which might dissolve drying agents and take up the leached Mg2+ and K+, serendipitously led to good enantioselectivity. Mechanistic aspects were supported
Enantioselective Mannich Reactions with the Practical Proline Mimetic <i>N</i>-(<i>p</i>-Dodecylphenyl-sulfonyl)-2-pyrrolidinecarboxamide
作者:Hua Yang、Rich G. Carter
DOI:10.1021/jo8027938
日期:2009.3.6
highly enantioselective and diastereoselective protocol for performing Mannichreactions has been developed by using a p-dodecylphenylsulfonamide-based proline catalyst. This catalyst facilitates the use of common, nonpolar solvents and increased concentrations as compared to alternative methods. A series of syn-selective Mannichreactions is reported, including the rapid access of α- and β-amino acids surrogates
A series of new modular bifunctional chiral thiourea organocatalysts were synthesized from natural Cinchona alkaloids and amino acids, and their performance in the aza-Henry reaction of nitroalkanes to imines, the Michaeladdition of acetylacetone to nitroolefins and the Michaeladdition of acetone to nitroolefins was investigated. Under the mild conditions, the important building blocks β-nitro amines