Asymmetric Synthesis of 2-(2-Pyridyl)aziridines from 2-Pyridineimines Bearing Stereogenic <i>N</i>-Alkyl Substituents and Regioselective Opening of the Aziridine Ring
作者:Diego Savoia、Giuseppe Alvaro、Romano Di Fabio、Andrea Gualandi、Claudio Fiorelli
DOI:10.1021/jo0614137
日期:2006.12.1
2-pyridinecarboxaldehyde and (S)-valinol, protected as its O-trimethylsilyl ether, gave the 1,2-disubstituted aziridine with good yield and diastereoselectivity. The analogous reaction performed on the imine derived from (S)-valine methyl ester gave the product containing the aziridine ring and the α-chloro ketone group coming from the attack of chloromethyllithium to the ester function. Other stereogenic
将氯甲基锂加到衍生自2-吡啶甲醛和(S)-缬氨醇的亚胺中,作为其O-三甲基甲硅烷基醚进行保护,得到的1,2-二取代的氮丙啶具有良好的收率和非对映选择性。对源自(S的亚胺)-缬氨酸甲酯得到含有氮丙啶环和α-氯酮基团的产物,该产物来自氯甲基锂对酯官能团的攻击。在氮上的其他立体烷基取代基给出的结果较不令人满意。此外,叠氮化方案不适用于其他不能二齿螯合的芳族亚胺,例如3-和4-吡啶亚胺和苯甲二胺。初步研究表明,通过内部或外部亲核试剂的攻击,可以进行2-(2-吡啶基)氮丙啶的区域和立体特异性开放反应。