An Unusual Acyliminium Cyclization and Other Drawbacks during an Attempted Synthesis of a Chiral Primary ?-Phosphinoalkanamine
作者:Jens Christoffers
DOI:10.1002/hlca.19980810506
日期:——
Studies towards the synthesis of a chiral primary α-phosphinoalkanamine 1a are reported. O-Activated. N-carbamate-protected phenylalaninol 3a did not undergo SN reaction with KPPh2: instead, after N-deprotonation, intramolecular substitution led to formation of the aziridine derivative 5a (Scheme 2). N-Phthalimido-protected, O-activated phenylalaninol 3b also underwent an intramolecular process on
报道了对手性伯α-膦烷基烷胺1a的合成的研究。O-已激活。N-氨基甲酸酯保护的苯丙氨醇3a没有与KPPh 2进行S N反应:相反,在N-去质子化之后,分子内取代导致形成氮丙啶衍生物5a(方案2)。N-邻苯二甲酰亚胺基保护的,O-激活的苯丙氨醇3b在用KPPh 2处理时也经历了分子内过程,即,这是不寻常的芳基-酰基环化反应,提供了(环氧甲氧基)异吲哚并[1,2- a ]异喹啉酮7(方案3)。与KPPh的反应2中,Ñ,Ñ二苄基保护和活化的苯丙3D最后产生的分子间小号Ñ反应产物2a中(方案4)。但是,证明不可能通过催化氢化进行脱苄基作用。