Synthesis and selected transformations of 2-unsubstituted 1-(adamantyloxy)imidazole 3-oxides: straightforward access to non-symmetric 1,3-dialkoxyimidazolium salts
作者:Grzegorz Mlostoń、Małgorzata Celeda、Katarzyna Urbaniak、Marcin Jasiński、Vladyslav Bakhonsky、Peter R Schreiner、Heinz Heimgartner
DOI:10.3762/bjoc.15.43
日期:——
Adamantyloxyamine reacts with formaldehyde to give N-(adamantyloxy)formaldimine as a room-temperature-stable compound that exists in solution in monomeric form. This product was used for reactions with α-hydroxyiminoketones leading to a new class of 2-unsubstituted imidazole 3-oxides bearing the adamantyloxy substituent at N(1). Their reactions with 2,2,4,4-tetramethylcyclobutane-1,3-dithione or with
金刚烷酰氧基胺与甲醛反应,得到N-(金刚烷氧基)甲醛甲胺,其为室温稳定的化合物,其以单体形式存在于溶液中。该产物用于与α-羟基亚氨基酮的反应,从而导致一类新的2-未取代的咪唑3-氧化物,在N(1)处带有金刚烷氧基取代基。它们与2,2,4,4-四甲基环丁烷-1,3-二硫酮或与乙酸酐的反应类似于1-烷基咪唑3-氧化物的反应,分别得到咪唑-2-硫酮和咪唑-2-酮。用阮内镍处理1-(金刚烷氧基)咪唑3-氧化物可得到相应的咪唑衍生物,而不会裂解N(1)-O键。最后,新咪唑N的O-烷基化反应1-溴戊烷或1-溴十二烷的二氧化钛可直接获得各种取代的非对称1,3-二烷氧基咪唑鎓盐。在氢溴酸存在下,金刚烷酰氧基胺与乙二醛和甲醛反应,生成对称的1,3-二(金刚烷氧基)-1 H-咪唑鎓溴化物,收率很高。后者在元素硫存在下用三乙胺脱质子化,可以原位生成相应的咪唑-2-亚基,后者捕获元素硫,最终生成1,3-二氢-2 H-咪唑-2-硫酮。