First asymmetric Diels-Alder reactions of furan and chiral acrylates. Usefulness of acid heterogenous catalysts
First asymmetric Diels-Alder reactions of furan and chiral acrylates. Usefulness of acid heterogenous catalysts
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DOI：
10.1021/jo961513k
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发表时间：
1996-12-27
影响因子：
3.6
通讯作者：
Pires, E
中科院分区：
文献类型：
--
作者：
Fraile, JM;Garcia, JI;Pires, E
硅胶负载的TiCl 4和ZnCl 2催化呋喃与丙烯酸甲酯、（1 R，2S，5 R）-薄荷酯和（1 R，2S，5 R）-8-苯基薄荷酯的反应。当反应在没有溶剂的情况下进行时获得最佳结果。内/外和非对映选择性取决于催化剂的性质和反应条件。对于（1 R，2S，5 R）-丙烯酸薄荷酯，最佳的不对称诱导率为44%de的内环加成物和20%de的外环加成物。与（1 R，2S，5 R）-8-苯基丙烯酸薄荷酯反应，得到68%de的内型环加成物和70%de的外型环加成物。
TiCl4 and ZnCl2 supported on silica gel catalyze the reactions of furan with methyl, (1R,2S,5R)-menthyl, and (1R,2S,5R)-8-phenylmenthyl acrylates. The best results are obtained when reactions are carried out without a solvent. The endo/exo and diastereofacial selectivities depend on the nature of the catalyst and on the reaction conditions. With the (1R,2S,5R)-menthyl acrylate 44% de in endo cycloadducts and 20% de in exo cycloadducts are the best asymmetric inductions. With the (1R,2S,5R)-8-phenylmenthyl acrylate 68% de in endo and 70% de in exo cycloadducts are obtained.