D'hooghe Matthias, Buyck Christophe, Contreras Jan, De Kimpe Norbert
Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Belgium.
Org Biomol Chem. 2008 Oct 21;6(20):3667-9. doi: 10.1039/b813890g. Epub 2008 Sep 4.
N-(1-Aryl-2,2-dichloropent-4-enylidene)amines were efficiently transformed into 5-bromomethyl-1-pyrrolinium bromides via electrophile-induced bromocyclization. The latter pyrrolinium salts were converted into novel 5-alkoxymethyl-2-aryl-3-chloropyrroles by reaction with alkoxides in the corresponding alcohol or in THF. This chemistry clearly deviates from the corresponding gamma,delta-unsaturated alpha,alpha-dialkylaldimines under similar conditions. Furthermore, treatment of 5-bromomethyl-1-pyrrolinium bromides with sodium hydroxide in water afforded a new entry into 2-aroylpyrroles by an unexpected ring transformation of intermediate aziridine derivatives, which could be isolated as well.
N-(1-芳基-2,2-二氯戊-4-亚烯基)胺通过亲电试剂诱导的溴环化反应高效转化为5-溴甲基-1-吡咯啉鎓溴化物。后者的吡咯啉鎓盐通过在相应醇或四氢呋喃中与醇盐反应转化为新型的5-烷氧基甲基-2-芳基-3-氯吡咯。这种化学过程明显不同于在类似条件下相应的γ,δ-不饱和α,α-二烷基醛亚胺。此外，在水中用氢氧化钠处理5-溴甲基-1-吡咯啉鎓溴化物，通过中间体氮丙啶衍生物意外的环转化，为合成2-芳酰基吡咯提供了一条新途径，中间体氮丙啶衍生物也可以被分离出来。
