An efficient synthesis of 3-trifluoromethylated 8-oxabicyclo[3.2.1]octa-2,6-dienes
作者:Yanli Wang、Shizheng Zhu、Guangyu Zhu、Qichen Huang
DOI:10.1016/s0040-4020(01)00709-8
日期:2001.8
vinyldiazomethanes 3 in the presence of furans resulted in the formation of a series of 3-trifluoromethylated 8-oxabicyclo[3.2.1]octa-2,6-dienes. The 4-substituent on the vinyldiazomethanes had great effects on the product distribution and the stereo- and regiochemistry of the [3+4] annulation products. The rhodium(II) acetate catalyzed reaction of 4-carbonyl substituted vinyldiazomethanes 3a–c with furans resulted
在呋喃存在下,乙酸铑(II)催化3-三氟甲基化的乙烯基重氮甲烷3的分解导致形成一系列3-三氟甲基化的8-氧杂双环[3.2.1] octa-2,6-二烯。乙烯基重氮甲烷上的4-取代基对产物分布以及[3 + 4]环化产物的立体和区域化学有很大影响。4-羰基取代的乙烯基重氮甲烷3a - c与呋喃的乙酸铑(II)催化反应生成环丙烯和[3 + 4]环化产物,而在氰基取代的乙烯基重氮甲烷3d的情况下,仅获得环加成产物。推测该反应遵循串联环丙烷化/ Cope重排机制。