手性硫脲叔胺催化不对称Michael加成反应合成α,α-双取代芳基氨基酸前体

Chiral Thiourea-tertiary Amine-Catalyzed Asymmetric Michael Addition for the Synthesis of α,α-Disubstituted Arylglycine Precursor

手性硫脲-叔胺催化剂(1)催化α-取代硝基乙酸酯与丙烯醛发生M ichael加成反应,合成了一系列α,α-双取代芳基氨基酸前体(4a^4 j),其结构经1H NMR,13C NMR和ESI-HR-MS表征。以合成4b为例,考察了溶剂,反应温度和反应时间等对反应的影响,结果表明,在110 mol%,甲苯为溶剂,于-60℃反应100 h的最佳反应条件下,4b的收率94%,74%e.e.。并合成了一系列4b的衍生物。

A series of α, α-disubstituted arylglycine precursors were synthesized by chiral thioureatertiary amine catalyst（1） through Michael reactions of α-substituted nitroacetates with acraldehyde. The structures were confirmed by ^1H NMR, ^13C NMR and ESI-HR-MS. The effects of solvent, reaction temperature and reaction time on the reaction were investigated for 4b. The optimal reaction conditions at -60 ℃ for 100 h were as follows： 1 was 10 mol% ; solvent was toluene. The yield of 4b was 94% with 74% e. e. under the optimal reaction conditions. A series of derivates of 4b were synthesized.