Chemoselectivity of the Reactions of Diazomethanes with 5-Benzylidene-3-phenylrhodanine
作者:Martin S. Seyfried、Anthony Linden、Grzegorz Mlostoń、Heinz Heimgartner
DOI:10.1002/hlca.200900149
日期:2009.9
The reactions of 5‐benzylidene‐3‐phenylrhodanine (2; rhodanine=2‐thioxo‐1,3‐thiazolidin‐4‐one) with diazomethane (7a) and phenyldiazomethane (7b) occurred chemoselectively at the exocyclic CC bond to give the spirocyclopropane derivatives 9 and, in the case of 7a, also the C‐methylated products 8 (Scheme 1). In contrast, diphenyldiazomethane (7c) reacted exclusively with the CS group leading to the
5-苄叉基-3-苯基若丹宁(2 ;罗丹宁= 2-硫代x-1,3-噻唑啉丁-4-酮)与重氮甲烷(7a)和苯基重氮甲烷(7b)的化学选择性发生在环外CC键上螺环丙烷衍生物9,在7a的情况下,还有C-甲基化产物8(方案1)。相反,二苯基重氮甲烷(7c)仅与CS基团反应,通过[2 + 3]环加成反应和“双向挤出反应”生成2-(二苯基亚甲基)-1,3-噻唑烷11 。治疗8或9b在室温下,在[Rh 2(OAc)4 ]的存在下,在回流CH 2 Cl 2和THF中用过量的7a分别生成1,3-噻唑烷-2,4-二酮15和20,分别,即,中间硫羰基叶立德的水解的产物。另一方面,在沸腾的甲苯中与7b和7c反应生成相应的2-亚甲基衍生物16、21a和21b。最后,11与7a的反应发生在贫电子的CC键上,该键与C groupO基团共轭。除了螺环丙烷23以外,C-甲基22也作为次要产物形成。产品(Z)-8、9a,