Tandem sigmatropic shifts in [4 + 2] cycloaddition reactions of 1,3-diazabuta-1,3-dienes with butadienylketene: synthesis of pyrimidinone derivatives
作者:Arun K. Sharma、S. Jayakumar、Maninder S. Hundal、Mohinder P. Mahajan
DOI:10.1039/b109922c
日期:2002.3.8
The reactions of 4-dialkylamino substituted 1,3-diazabuta-1,3-dienes 1 with butadienylketene 2, are shown to undergo [4 + 2] cycloadditions to yield 5-(buta-1′,3′-dienyl)pyrimidinone 4 and tandem [1,5]H and [1,5]SCH3 shifts are shown to accompany the [4 + 2] cycloaddition reactions of 4-dialkylamino-4-methylthio substituted 1,3-diazabuta-1,3-dienes 5 with 2. The regioselective reactions of N-arylamino-1,3-diazabuta-1,3-dienes 11 and 14 with butadienylketene 2 are reported to yield 5-(buta-1′,3′-dienyl)-2-dialkylaminopyrimidin-4(3H)-one 13
and a mixture of 5-(buta-1′,3′-dienyl)-2-methylthiopyrimidin-4(3H)-one 17, 2-methylthio-5-[1′-(N-phenylamino)but-2′-enyl]pyrimidin-4(3H)-one 19 and 2-methylthio-5-[3′-(N-phenylamino)but-1′-enyl]pyrimidin-4(3H)-one 20, respectively. Tandem [1,5]H, [1,3]NHPh and [1,5]NHPh shifts are involved in the formation of pyrimidinones 19 and 20. The Diels–Alder reactions of the 5-dienylpyrimidinones with dimethyl acetylenedicarboxylate (DMAD) and 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) yielded corresponding cycloadducts.
4- 二烷基氨基取代的 1,3-二氮杂吲哚-1,3-二烯 1 与丁二烯酮 2 发生[4 + 2]环加成反应,生成 5-(丁-1′、3′-二烯基)嘧啶酮 4,并显示 4-二烷基氨基-4-甲硫基取代的 1,3-二氮杂-1,3-二烯 5 与 2 的[4 + 2]环加成反应伴随着串联[1,5]H 和[1,5]SCH3 迁移。据报道,N-芳基氨基-1,3-二氮杂吲哚-1,3-二烯 11 和 14 与丁二烯基酮 2 发生了区域选择性反应,生成了 5-(丁-1′,3′-二烯基)-2-二烷基氨基嘧啶-4(3H)-酮 13 和 5-(丁-1′,3′-二烯基)-2-二烷基氨基嘧啶-4(3H)-酮的混合物、3′-二烯基)-2-甲硫基嘧啶-4(3H)-酮 17、2-甲硫基-5-[1′-(N-苯基氨基)丁-2′-烯基]嘧啶-4(3H)-酮 19 和 2-甲硫基-5-[3′-(N-苯基氨基)丁-1′-烯基]嘧啶-4(3H)-酮 20 的混合物。[1,5]H、[1,3]NHPh 和 [1,5]NHPh 串联转变参与了嘧啶酮 19 和 20 的形成。5-二烯基嘧啶酮与乙炔二甲酸二甲酯(DMAD)和 4-苯基-1,2,4-三唑啉-3,5-二酮(PTAD)的 Diels-Alder 反应生成了相应的环加载产物。