Cycloisomerization of Enynes via Rhodium Vinylidene-Mediated Catalysis
作者:Hahn Kim、Chulbom Lee
DOI:10.1021/ja052775j
日期:2005.7.1
A novel rhodium-catalyzed cycloisomerization has been developed which converts various acyclic enynes to their cyclic diene isomers with endoselectivity. Both [RhCl(COD)]2/P(4-FC6H4)3 and RhCl(PPh3)3 catalyst systems are effective in promoting the C-C bond-forming cyclization of enynes to furnish carbo- and heterocycles in good to excellent yield. Deuterium labeling studies suggest that the reaction
一种新型的铑催化的环异构化已被开发出来,它可以将各种无环烯炔转化为具有内选择性的环状二烯异构体。[RhCl(COD)]2/P(4-FC6H4)3 和 RhCl(PPh3)3 催化剂体系均能有效促进烯炔的 CC 键形成环化,从而以良好至极好的收率提供碳环和杂环。氘标记研究表明,该反应通过形成亚乙烯基铑,随后与烯烃进行 [2 + 2] 环加成和所得环丁烷开环来进行。这些机理研究重新评估了先前提出的反应途径,并导致发现了一种新的环异构化反应,该反应涉及环化时烯炔底物的炔烃上甲硅烷基和硒基取代基的迁移。