Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas , Instituto Politécnico Nacional , Prol. Carpio y Plan de Ayala, S/N , Mexico City 11340 , Mexico.
Departamento de Química Orgánica, Facultad de Ciencias Químicas , Universidad Autónoma de Chihuahua , Circuito Universitario S/N , Chihuahua , Chih. 31125 , Mexico.
J Org Chem. 2018 May 18;83(10):5347-5364. doi: 10.1021/acs.joc.7b02344. Epub 2018 Apr 26.
An efficient and alternative synthesis of exo-imidazolidin-2-one dienes is described. A condensation reaction was carried out with bis-imino derivatives, diacetyl, and triphosgene, affording symmetrically N, N-disubstituted dienes. The use of alkyl methyl α-diketones led to the formation of nonsymmetrical dienes, which underwent isomerization to provide more stable inner-outer-ring dienes under Lewis acid conditions. Evaluation was made of the reactivity as well as regio- and stereoselectivity of these dienes in Diels-Alder reactions. They proved to be highly reactive and selective. DFT calculations of the transition states accounted for their behavior.
描述了一种高效且可替代的外-咪唑烷-2-酮二烯的合成方法。通过双亚氨基衍生物、二乙酰和三光气进行缩合反应，得到对称的 N，N-二取代二烯。使用烷基甲基α-二酮导致形成非对称二烯，这些二烯在路易斯酸条件下发生异构化，形成更稳定的内-外环二烯。评估了这些二烯在 Diels-Alder 反应中的反应性以及区域和立体选择性。结果表明它们具有高反应性和选择性。过渡态的 DFT 计算解释了它们的行为。
