Asymmetric Strecker Synthesis of α-Amino Acids via a Crystallization-Induced Asymmetric Transformation Using (<i>R</i>)-Phenylglycine Amide as Chiral Auxiliary
作者:Wilhelmus H. J. Boesten、Jean-Paul G. Seerden、Ben de Lange、Hubertus J. A. Dielemans、Henk L. M. Elsenberg、Bernard Kaptein、Harold M. Moody、Richard M. Kellogg、Quirinus B. Broxterman
DOI:10.1021/ol007042c
日期:2001.4.1
[reaction: see text]. Diastereoselective Strecker reactions based on (R)-phenylglycine amide as chiral auxiliary are reported. The Strecker reaction is accompanied by an in situ crystallization-induced asymmetric transformation, whereby one diastereomer selectively precipitates and can be isolated in 76-93% yield and dr > 99/1. The diastereomerically pure alpha-amino nitrile obtained from pivaldehyde
[反应:请参见文字]。报道了基于(R)-苯基甘氨酸酰胺作为手性助剂的非对映选择性Strecker反应。Strecker反应伴随有原位结晶诱导的不对称转变,由此一种非对映异构体选择性沉淀,可以76-93%的产率分离,且dr> 99/1。从三元乙醛(R1 = t-Bu,R2 = H)获得的非对映异构纯α-氨基腈经三步转化为(S)-叔亮氨酸,收率73%,ee≥98%。