Ma Shengming, Yu Zhanqian
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, PR China.
Chemistry. 2004 Apr 19;10(8):2078-87. doi: 10.1002/chem.200305341.
The oxidative cyclization/dimerization reaction between two classes of allenes with different functionalities was reported to provide an efficient route to polysubstituted 4-(3'-furanyl)-2(5H)-furanones, which are not readily available from the known methods. The highly optically active butenolides could be easily formed from the optically active 2,3-allenoic acids, which was obtained conveniently through chiral resolution with optically active amines, that is, cinchonidine or alpha-methyl benzylamine. A mechanistic study showed that the reaction proceeded via a matched double oxypalladation-reductive elimination process. The Pd(II) species may be regenerated via the subsequent cyclometallation of two equivalents of 1,2-allenyl ketones with Pd(0) and protonlysis of Pd enolates formed with the in situ generated HCl.
据报道，两类具有不同官能团的丙二烯之间的氧化环化/二聚反应为多取代的4-(3'-呋喃基)-2(5H)-呋喃酮提供了一条有效途径，而这些呋喃酮通过已知方法不易获得。高光学活性的丁烯内酯可由光学活性的2,3-丙二烯酸轻松形成，该丙二烯酸可通过与光学活性胺（即辛可尼定或α-甲基苄胺）进行手性拆分方便地获得。机理研究表明，该反应通过匹配的双氧钯化-还原消除过程进行。Pd(II)物种可通过两当量的1,2-烯丙基酮与Pd(0)的后续环金属化以及与原位生成的HCl形成的Pd烯醇盐的质子解作用而再生。
