Easy access to medium rings by entropy/strain reduction, Part 3. Competition between dihydroazepine and enamine formation in reaction of tetrahalosubstituted dibromides with primary amines
作者:James G. Walsh、Declan G. Gilheany
DOI:10.1002/jhet.5570390624
日期:2002.11
of Z,Z-2,3,4,5-tetrahalo-2,4-dien-1,6-dibromides (3, R1 - R4 = Cl, Br) with primary amines in the presence of potassium carbonate leads to both the dihydroazepines 4 and secondary enamines 5. The formation of enamine is suppressed with toluene sulfonamide as nitrogen source. (2Z,4Z)-2,3,4,5-Tetrabromo-hexa-2,4-diene-1,6-diol (2, R1 - R4 = Br) is atropisomeric in solution.
Z,Z-2,3,4,5-四卤代2,4-二烯-1,6-二溴化物(3,R 1 -R 4 = Cl,Br)在碳酸钾存在下与伯胺的反应同时导致二氢a庚因4和仲烯胺5。用甲苯磺酰胺作为氮源抑制烯胺的形成。(2Z,4Z)-2,3,4,5-四溴-六-2,4-二烯-1,6-二醇(2,R 1 -R 4= Br)在溶液中为阻转异构体。