Hodgson David M, Fleming Matthew J, Stanway Steven J
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom.
J Org Chem. 2007 Jun 22;72(13):4763-73. doi: 10.1021/jo070291v. Epub 2007 May 26.
The scope and limitations of lithium 2,2,6,6-tetramethylpiperidide (LTMP)-modified reductive alkylation of epoxides is detailed. A variety of organolithiums are added to terminal and 2,2-disubstituted epoxides in the presence of LTMP to generate alkenes in a completely regio- and highly stereoselective manner. Arylated alkenes, dienes, allylsilanes, and enynes are accessed using this procedure. The methodology is applied in the synthesis of the roller leaf moth pheromone, (3E,5Z)-dodecadienyl acetate. The corresponding reaction without LTMP has also been examined, and a study using deuterated epoxides provides insight into the mechanism. In the presence of LTMP, Grignard reagents are also shown to produce E-alkenes directly from epoxides.
详细阐述了2,2,6,6-四甲基哌啶锂（LTMP）修饰的环氧化合物还原烷基化反应的范围和局限性。在LTMP存在下，将多种有机锂试剂加入到末端环氧化合物和2,2-二取代环氧化合物中，以完全区域选择性和高立体选择性的方式生成烯烃。通过该方法可以得到芳基化烯烃、二烯、烯丙基硅烷和烯炔。该方法应用于卷叶蛾信息素（3E,5Z）-十二碳二烯基乙酸酯的合成。还研究了无LTMP时的相应反应，并且使用氘代环氧化合物的研究为反应机理提供了深入了解。在LTMP存在下，格氏试剂也能直接从环氧化合物生成E型烯烃。
