Diene-transmissive hetero Diels–Alder reaction of cross-conjugated azatrienes with ketenes: a novel and efficient, stereo-controlled synthetic method for hexahydroquinolinones
作者:Takao Saito、Satoru Kobayashi、Masato Ohgaki、Mari Wada、Chikako Nagahiro
DOI:10.1016/s0040-4039(02)00303-9
日期:2002.4
dimethylketene at room temperature to afford [2+2] cycloadducts, while the reaction with dichloroketene produced [4+2] cycloadducts. Upon heating, the [2+2] cycloadducts underwent a [1,3] sigmatropic rearrangement giving the formal [4+2] cycloadducts. The second Diels–Alder reaction of the [4+2] mono-adducts with electron-deficient dienophiles such as tetracyanoethylene, N-phenylmaleimide and methyl vinyl
交叉共轭的氮杂三烯,N-芳基-,N-烷基-或N-二甲基氨基-二β-苯乙烯基甲亚胺,在室温下与二苯基乙烯酮和二甲基乙烯酮反应,生成[2 + 2]环加合物,而与二氯乙烯酮的反应生成[4+ 2]环加合物。加热后,[2 + 2]环加合物进行了[1,3]σ重排,得到了正式的[4 + 2]环加合物。[4 + 2]单加合物的第二次狄尔斯-阿尔德反应与缺电子的亲二烯体,如四氰基乙烯,N-苯基马来酰亚胺和甲基乙烯基酮立体选择性地得到六氢喹啉酮衍生物。在β-和β'-位带有不同取代基的交叉共轭氮杂三烯也以高度位点,区域和立体选择性的方式经历了二烯可传递的杂Diels-Alder反应。