含釕金屬亞乙烯基錯合物之烯炔的環異構化反應

Cycloisomerization Reactions of Enynes Involving Ruthenium Vinylidene Complex

吳榮諭(Rong-Yu Wu)

指導教授 ： 林英智

國立臺灣大學/理學院/化學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.00444

摘要

第一部分
釕金屬錯合物[Ru]NCCH3+催化烯炔化合物1a-d進行環化反應，生成產物2a-d，經由烯炔的歧化反應，其中包含在反應之中的結構重排。此環異構化反應經由π配位的中間物，進而生成帶正電荷的三員環中間產物。之後，有兩個路徑可進行，皆得到相同產物。隨著催化劑濃度的不同，其中2a會更進一步行脫水反應，而當中有兩個不同位置的質子氫可脫去而形成3a和4a。在實驗進行期間，意外的發現使用布式酸或酸性鹽取代釕金屬化合物跟烯炔進行反應，會因為三級碳陽離子的生成而得到5a-d。以上的反應皆由核磁共振光譜所証實。
第二部分
鄰乙烯氧基乙炔苯6和釕金屬錯合物[Ru]Cl在不同的溶劑中進行反應將得到不同的結果。在像是醇類具有親核性的溶劑中，會有催化反應的發生而生成化合物7a-c。此反應經由釕金屬亞乙烯基錯合物作為中間體被乙烯氧基末端的碳攻擊形成七員環中間體，再被醇類攻擊形成含乙縮醛的產物。若是改成在像二氯甲烷非親核性的溶劑中，將會形成經重排過後的亞乙烯基錯合物8而不是有機化合物。此重排經由[2 + 2] 環加成形成雙環金屬碳烯和碳和碳之間的斷裂而得到產物。若將錯合物8和鹼反應將形成錯合物9，再將9更進一步和碘甲烷和碘丙烯反應形成錯合物10a和10b。化合物11是由錯合物9在甲基氰中反應而得。將錯合物8在甲醇攪拌將形成甲氧基碳烯金屬錯合物12，若是反應中含有氯化鉀，則還會形成化合物7a和釕金屬錯合物[Ru]Cl。以上的反應皆由核磁共振所鑒定而得。

關鍵字

釕 ； 催化反應 ； 結構重排 ； 烯炔歧化 ； 環異構化 ； 催化反應 ； 亞乙烯基

並列摘要

Part I
Cycloisomerization reactions of 1,6-enynes 1a-d containing propargylic alcohol and olefin groups are catalyzed by [Cp(dppe)RuNCCH3]PF6 to yield the products 2a-d by enyne metathesis involving skeletal rearrangement. The cycloisomerization proceeds via a π-coordinated complex followed by formation of a cyclopropyl carbinyl cation intermediate. Two different pathways are proposed to lead to the product. Dehydration only happens for 2a which contains phenyl substituents in 1,6-enyne. Two different pathways lead to two different products 3a and 4a. Use of the acidic salt NH4PF6 including Brønsted acids, instead of the ruthenium complex, in the reaction of enyne 1a-d causes nucleophilic cyclization to afford 5a-d. The protonation at the olefinic part is attributed to a relatively stable tertiary carbocation, which subsequently proceeds via nucleophilic attack of the cation. These reactions and their mechanism are corroborated by D-labeling and 13C-labling experiments using 1D and 2D NMR spectra analysis.
Part II
Derivative of ethynylbenzene 6 containing a vinyloxy group at ortho-positon reacts with Cp(PPh3)2RuCl in the nucleophilic or non-nucleophilic solvent to lead to such different results. In nucleophilic solvent such as alcohols, catalytic reaction takes place to afford benzoxepine derivatives 7a-c. Via the vinlyidene intermediate, it undergoes the nucleophilic attack by the terminal carbon of vinyloxy group followed by alcohols attending to form a seven-membered ring containing an acetal group, which subsequently goes through proton-induced demetallation to obtain product 7a-c. In non-nucleophilic solvent such as dichloromethane, reaction forms the cationic ruthenium vinylidene complex 8 rather than organic compound. The vinylidene intermediate via [2 + 2] cycloaddition leads to byclic carbene, which undergoes C-C bond cleavage to form the product δ, γ-unsaturated vinylidene complex 8. Use of base proceeds via the deprotonation of complex 8 affording acetylide complex 9, which is alkylated by methyl iodide and allyl iodide to form complexes 10a and 10b, respectively. Compound 11 can be obtained when stirring in acetonitrile because of forming the stable complex [Cp(PPh3)2RuNCCH3]PF6. Stirring the complex 8 in the methanol gives the complex 12, which is also obtained including compound 7a and ruthenium chloride generated in the presence of potassium chloride. All reactions and mechanism above is elucidated by D-labeling experiment and characterized by 1H NMR, 13C NMR, and 2-D NMR spectra.

並列關鍵字

ruthenium ； catalytic reaction ； skeletal rearrangement ； enyne metathesis ； cycloisomerization ； catalytic reaction ； vinylidene

參考文獻

17. (a) Campos, J.; Pineda, M. J.; Gómez, J. A.; Entrena, A.; Trujillo, M. A.; Gallo, M. Á.; Espinosa, A. Tetrahedron 1996, 52, 8907. (b) Gómez, J. A.; Trujillo, M. Á.; Campos, J.; Gallo, M. Á.; Espinosa, A. Tetrahedron 1998, 54, 13295. (c) Trujillo, M. Á.; Gómez, J. A.; Campos, J.; Espinosa, A.; Gallo, M. Á. Tetrahedron 2001, 57, 3951. (d) Campos, J.; Gómez, J. A.; Trujillo, M. Á.; Gallo, M. Á.; Espinosa, A. Il Farmaco 1997, 52, 263.

2. (a) Chung, C. P.; Chen, C. C.; Lin, Y. C.; Liu, Y. H.; Wang, Y. J. Am. Chem. Soc. 2009, 131, 18366. (b) Cheng, C. W.; Kuo, Y. C.; Chang, S. H.; Lin, Y. C.; Liu, Y. H.; Wang, Y. J. Am. Chem. Soc. 2007, 129, 14974. (c) Chang, W. C.; Cheng, C. W.; Ma, H. W.; Lin, Y. C.; Liu, Y. H. Organometallics 2011, 30, 2747.

16. (a) Bruce, M. I.; Wallis, R. C. Aust. J. Chem. 1979, 32, 1471. (b) Marco-Contelles, J.; Ruiz-Caro, J.; Mainetti, E.; Devin, P.; Fensterbank, L.; Malacria, M. Tetrahedron 2002, 58, 1147. (c) Lemière, G.; Gandon, V.; Carious, K.; Hours, A.; Fukuyama, T.; Dhimane, A. L.; Fensterbank, L.; Malacria, M. J. Am. Chem, Soc. 2009, 131, 2993.

9. Nieto-Oberhuber, C.; Muñoz, M. P.; Buñuel, E.; Nevado, C.; Cárdenas, D. J.; Echavarren, A. M. Angew. Chem., Int. Ed. 2004, 43, 2402.

1. Bruce, M. I. Chem. Rev. 1991, 91, 197.