含環丁烷及丙炔基之化合物與釕金屬錯合物反應之研究

Abstract

利用釕金屬錯合物[Ru]Cl ([Ru] = Cp(PPh3)2Ru)與含四環之有機炔類1，在甲醇溶液中反應，可得釕亞乙烯錯合物2。假若將有機物1在參鍵旁邊延伸一個亞甲基形成有機物5，在同樣條件下，則與[Ru]Cl進行分子內環化反應生成釕卡賓錯合物6。錯合物2 與乙腈反應，釋放出烯炔有機物7。釕乙腈錯合物[Ru]MeCN+也可催化1的脫水反應得到7。再將7作環氧化反應得到含四環並環氧基之有機物 8。釕錯合物[Ru]Cl與8在二氯甲烷溶液中進行四環擴環反應，可得釕錯合物10。但是相同反應在甲醇溶液中，則可進行進一步環化反應得到含兩個五環稠環釕錯合物12a。此外，10在酸性甲醇溶液中也可以經環化反應轉化為12a。但是若無酸的存在，10在甲醇溶液中會脫氫離子得到11。錯合物10在二氯甲烷和氟硼酸溶液中反應，可進行氟加成反應得到錯合物13。單晶繞射確定了兩個釕錯合物6與12a的固態結構。

Reactions of [Ru]Cl ([Ru] = Cp(PPh3)2Ru) with three alkynyl compounds 1, 5, and 8, each containing a cyclobutyl group, are explored. For 1, the reaction gives the vinylidene complex 2, with a cyclobutylidene group via a dehydration at CδH and CγOH. With an additional methylene group, 5 reacts with [Ru]Cl to afford the cyclic oxacarbene complex 6. The reaction proceeds via a vinylidene intermediate followed by an intra-molecular cyclization reaction by a nucleophilic addition of the hydroxyl group onto Cα of the vinylidene ligand. Deprotonation of 2 with NaOMe produces the acetylide complex 3 and alkylations of 3 by allyl iodide, methyl iodide and ethyl iodoacetate generate 4a-c, respectively, each with a stable cyclobutyl group. Dehydration of 1 is catalyzed by the cationic ruthenium acetonitrile complex at 70ºC to form the 1,3-enyne 7. Epoxidation reaction of the double bond of 7 yields the oxirane 8. Ring-expansion of the cyclobutyl group of 8 is readily induced by the acidic salt NH4PF6 to afford the 2-ethynyl substituted cyclopentanone 9. The same ring expansion is also seen in the reaction of [Ru]Cl with 8 in CH2Cl2 affording the vinylidene complex 10, also obtainable from 9 and [Ru]Cl. But, in MeOH, the same reaction of [Ru]Cl with 8 affords the bicyclic oxacarbene complex 12a via an additional cyclization reaction. Transformation of 10 to 12a is readily achieved in MeOH/HBF4, but, in MeOH alone, the acetylide complex 11 is produced from 10. In the absence of MeOH, cyclization of 10, induced by HBF4, is followed by a fluorination to afford complex 13. Crystal structures of 6 and 12a’ are determined by singel crystal diffraction analysis.