多核釕金屬亞乙烯基錯合物的合成以及含釕金屬亞乙 烯基錯合物的Diels-Alder 反應

Preparation of Multinuclear Ruthenium Vinylidene Complexes and The Diels-Alder Reaction of Ruthenium Vinylidene Complexes

蔡玟儒(Wen-Ru Tsai)

指導教授 ： 林英智

國立臺灣大學/理學院/化學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.00715

摘要

將Cp(PEt3)2RuCl與過量之丙炔和KPF6在甲醇中反應，可得單取代之釕金屬亞乙烯基錯合物2，再藉由去質子反應可製得釕金屬炔基錯合物3。一系列具有不同官能基之雙取代陽離子釕金屬亞乙烯基錯合物4a - 4c，可藉由錯合物3和不同的一級鹵烷類在二氯甲烷中反應而得。錯合物4a和Cp(PEt3)2RuCl以一比一的比例在過量KPF¬6的存在下，可製得雙核釕金屬亞乙烯基錯合物5，錯合物5去質子產生雙核亞乙烯基炔基錯合物6。以錯合物6針對不同官能基之一級鹵烷類在二氯甲烷中進行反應，可得一系列帶二價正電荷之雙核釕金屬亞乙烯基錯合物7a - 7d。藉由錯合物7a的結構特性，運用類似的反應條件，我們成功地將系統延伸至三金屬化合物，順利的合成出三核亞乙烯基錯合物8。
Cp(PEt3)2¬RuCl與一系列的1,5-烯炔化合物反應，形成對應的亞乙烯基錯合物9a - 9c。9a - 9c在甲醇中可被甲醇鈉去質子，形成釕金屬炔基錯合物10a - 10c。錯合物10c與3-溴丙炔反應可生成陽離子釕金屬亞乙烯基錯合物11c。11aa - 11ad也是運用類似的方法，將釕金屬炔基錯合物10a加入所對應的一級鹵化物進行反應而得。值得注意的是，含兩個丙烯基的錯合物11aa在其蒽基與接在β碳原子上的丙烯基進行了分子內的Diels-Alder反應。錯合物11aa在40 oC溶液中經過了三天，完全轉變成新的錯合物12aa。推測錯合物11aa的立體阻礙與電子結構的效應造成了分子內的Diels-Alder反應發生。另一方面，錯合物11ac必須在更高的溫度下，於二氯甲烷溶液中加熱迴流兩天，才能夠完成Diels-Alder反應，使錯合物11ac轉變成12ac。
釕金屬亞丙二烯基錯合物13a和格林鈉試劑HC≡CCH2MgBr，在THF下反應，得到淡黃色的炔基錯合物14a。錯合物14a在甲醇的加入下立即進行質子化反應生成錯合物15ab。而另外一個錯合物13b在同樣的條件下，形成釕金屬亞乙烯基錯合物15be與15bf，推測其必定經過亞乙烯基錯合物的中間體14be與14bf。錯合物14a繼續與甲基碘進行甲基化反應形成亞乙烯基錯合物15aa，產率也相當的不錯。從末端含有炔基的錯合物15aa、Cp(PEt3)2Cl、KPF6的甲醇溶液攪拌反應可合成出另外一種型式的雙核亞乙烯基錯合物16aa。但不幸的，錯合物16aa無法進一步的進行去質子反應以得到單一產物，而分解形成無法鑑定的化合物。
Cp(PEt3)2RuCl與醇類有機化合物17和AgPF6，在二氯甲烷溶液中反應，生成陽離子亞丙二烯錯合物18a。而Cp(PPh3)2OsBr則是在加入了化合物17與KPF6在甲醇中反應，生成了亞乙烯基錯合物19b。推測其形成的過程，經過亞丙二烯錯合物的中間體18b，隨後甲醇再加成到γ碳上而形成。錯合物19b在加入了甲醇鈉進行去質子反應後，得到產率不錯的黃色固體炔基錯合物20b。

關鍵字

釕金屬 ； 亞乙烯基化合物 ； 炔基化合物 ； 亞丙二烯基化合物 ； Diels-Alder反應

並列摘要

Treatment of [Ru]-Cl ([Ru] = Cp(PEt3)2Ru) with propyne in the presence of KPF6 in methanol affords {[Ru]=C=C(H)Me}[PF6] (2). Deprotonation of 2 with NaOMe yields complex [Ru]-C≡C-Me (3) isolated as yellow solid in high yield. Alkylation of 3 with HC≡CCH2Br in the presence of KPF6 yields the air-stable cationic vinylidene complex {[Ru]=C=C(Me)CH2C≡CH}[PF6] (4a) in high yield. Complexes {[Ru]=C=C(Me)CH2R}[PF6] (4b, R = CH=CH2; 4c, R = CO2Et) are similarly prepared from the corresponding halides in high yield. Reaction of the terminal alkynyl group of 4a with [Ru]-Cl affords the bisvinylidene complex {[Ru]=C=C(Me)CH2C(H)=C=[Ru]}[2PF6] (5) which deprotonates to give the ruthenium vinylidene acetylide complex {[Ru]=C=C(Me)CH2C≡C-[Ru]}[PF6] (6) in the presence of base. Alkylations of complex 6 with various primary alkyl halides RCH2X afford the corresponding cationic ruthenium bis-vinylidene complexes {[Ru]=C=C(Me)CH2C(CH2R)=C=[Ru]}[2PF6], (7a, R = C≡CH; 7b, R = CH=CH2, 7c, R = CO2Et, 7d, R = CO2Me). The trinuclear tris-vinylidene complex {[Ru]=C=C(Me)CH2C(CH2CH=C=[Ru])=C=[Ru]}[3PF6] (8) was prepared by treatment of a methanol solution of 7a with [Ru]-Cl containing KPF6.
A number of 1,5-enynes have been synthesized. The reaction of [Ru]-Cl with these enynes generates the corresponding vinylidene complexes {[Ru]=C=CHCH(R)CH2CH=CH2}[PF6] (9a, R = 9-chloro-10-anthracenyl; 9b, R = p-C6H4F; 9c, R = p-C6H4OMe). Treatment of complexes 9a-9c with NaOMe in MeOH causes the formation of ruthenium acetylide complexes [Ru]-C≡CCH(R)CH2CH=CH2 (10a, R = 9-chloro-10-anthracenyl; 10b, R = p-C6H4F; 10c, R = p-C6H4OMe). Alkylation of 10c with propargyl bromide affords the cationic ruthenium vinylidene complex {[Ru]=C=C(CH2C≡CH)CH(p-C6H4OMe)CH2CH=CH2}[PF6] (11c). Conversion to the alkylation products {[Ru]=C=C(CH2R)CH(C14H8Cl)CH2CH=CH2}[PF6] (11aa, R = CH=CH2; 11ab, R = CO2Et; 11ac, R = C(CH3)=CH2) were also achieved by the reaction of 10a with the corresponding primary halides. Surprisingly complex 11aa containing two allylic groups undergoes the Diels-Alder reaction between the anthracene and the terminal vinyl group of the allylic at Cβ. In dichloromethane, the cationic complex 11aa completely transforms into complex 12aa at 40°C for three days. Complex 11ac, dissolved in CH2Cl2 at 40 oC under nitrogen for one day, was not converted to the Diels-Alder reaction product 12ac yet. Only under more forcing condition, e.g. at 60 oC for 2 days, complex 11ac will transform to complex 12ac completely. The methyl group of dienophile encumbers the approach to the diene, so it must raise the temperature for the Diels-Alder reaction.
The light yellow acetylide complex [Ru]-C≡CC(p-C6H5OMe)2CH2C≡CH (14a) was obtained from the reaction of ruthenium allenylidene complex {[Ru]=C=C=C(p-C6H5OMe)2}[PF6] (13a) with Grignard reagent HC≡CCH2MgBr in THF. Under similar reaction conditions, vinylidene complexes {[Ru]=C=CHC(C4H3O)2CH2R’}[PF6] (15be, R = C≡CH; 15bf, R = CH=CH2) were also obtained by reaction of {[Ru]=C=C=C(C4H3O)2}[PF6] (13b) with the corresponding Grignard reagents. Protonation of 14a gave the vinylidene complex [Ru]=C=C(H)CH(p-C6H5OMe)2CH2C≡CH}[PF6] (15ab) and methylation of 14a with methyliodide afforded the vinylidene complex {[Ru]=C=C(Me)CH(p-C6H5OMe)2CH2C≡CH}[PF6] (15a) in essentially quantitative yield. Another type of bis-vinylidene complex {[Ru]=C=C(Me)C(p-C6H5OMe)2CH2CH=C=[Ru]}[2PF6] (16a) has been synthesized from complex 15a, [Ru]-Cl and KPF6 in MeOH. Deprotonation of 16a with NaOMe afforded only decomposition to unidentified complexes.
Treatment of [Ru]-Cl with 1-(1-allylcyclohexyl)prop-2-yn-1-ol (17) in the presence of AgPF6 in CH2Cl2 leads to the cationic ruthenium allenylidene complex {[Ru]=C=C=CHC(C5H10)CH2CH=CH2}[PF6] (18a). Reaction of complex [Os]-Br ([Os] = Cp(PPh3)2Os) with 17 in the presence of KPF6 in methanol generates the vinylidene complex {[Os]=C=CHCH(OMe)C(C5H10)CH2CH=CH2}[PF6] (19b) possibly via the formation of allenylidene intermediate followed by methoxy group addition at Cγ. Deprotonation of the complex 19b in the presence of NaOMe leads to the acetylide complex 20b, [Os]-C≡CCH(p-PhOMe)CH2CH=CH2, isolated as yellow solid in high yield.

並列關鍵字

ruthenium ； vinylidene ； acetylide ； allenylidene ； Diels-Alder Reaction

參考文獻

2. Bruce, M. I.; Wallis, R. C. J. Organomet. Chem. 1987, 161, C1.

3. Davision, A.; Selegue, J. P. J. Am. Chem. Soc. 1978, 100, 7763.

4. Boland, B. E.; Fam. S. A. J Organomet. Chem. 1979, 172, C29.

6. King, R. B.; Saran, M. S. J. Chem. Soc. Chem. Commun. 1972, 1053.

8. Puerta, M. C.; Valerga, P. Coord. Chem, Rev. 1999, 195, 977.