Diastereoselective synthesis of aziridines from (1R)-10-(N,N-dialkylsulfamoyl)isobornyl 2H-azirine-3-carboxylates
作者:Yolanda S. P. Álvares、M. José Alves、Nuno G. Azoia、Jamie F. Bickley、Thomas L. Gilchrist
DOI:10.1039/b202321k
日期:——
Reaction of the chiral azirine 1a with nucleophiles and dienes is described. Thiols, heteroaromatic nitrogen compounds and phenylmagnesium bromide add to the azirine 1a to give functionalised aziridines 2/3a–h. X-Ray crystal structures for the products 3e and 3g have been obtained. Diastereodifferentiation of the two faces of the azirine 1a is observed in most cases, but only thiophenol gives a single diastereomer (2a). Most mixtures of diastereomers were separated by dry flash chromatography. Benzylamine produced a dimer of the original azirine 1a,
compound 9. Representative conjugated dienes (cyclopentadiene, furan and open chain dienes) were added to the chiral azirine 1a. Only poor selectivities were observed. The selectivity was not significantly enhanced in the cycloaddition of cyclopentadiene to the more bulky azirine 1b.
介绍了手性氮丙啶 1a 与亲核物和二烯的反应。硫醇、杂芳香族氮化合物和苯基溴化镁加入到氮丙啶 1a 中,得到官能化氮丙啶 2/3a-h。产物 3e 和 3g 的 X 射线晶体结构已经获得。在大多数情况下,都能观察到氮丙啶 1a 两个面的非对映异构,但只有噻吩酚能产生单一的非对映异构体(2a)。大多数非对映异构体的混合物都是通过干闪蒸色谱法分离出来的。苄胺产生了原始氮丙啶 1a 的二聚体,即化合物 9。将代表性的共轭二烯(环戊二烯、呋喃和开链二烯)加入手性氮丙啶 1a。只观察到较差的选择性。在环戊二烯与更大体积的氮丙啶 1b 进行环加成反应时,选择性也没有明显提高。