Preparation of multinuclear Ruthenium Vinylidene Complexes and Their Deprotonation Reactions
Date Issued
2006
Date
2006
Author(s)
Liu, Chung-Wei
DOI
en-US
Abstract
將Cp(PEt3)2RuCl與過量之苯基乙炔和KPF6在甲醇中反應可得單取代之釕金屬亞乙烯基化合物2，藉由去質子反應可製得釕金屬炔化合物3。一系列具有不同官能基之雙取代陽離子性釕金屬亞乙烯基化合物4a~4g可藉由化合物3和不同的一級鹵烷類在二氯甲烷中反應而得。針對單核釕金屬亞乙烯基化合物4a~4g進行去質子反應成功的合成出中性釕金屬環丙烯基錯合物5a、5b、5f 和釕金屬呋喃錯合物6d、6g。
化合物4c和Cp(PR3)2RuCl以一比一的比例在過量KPF6的存在下可製得雙核釕金屬亞乙烯基化合物7w和7x，藉由去質子反應可由7w和7x得到雙核亞乙烯基炔化合物8w和8x。以化合物8w和8x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化合物9w~15w和9x~13x，15x。
針對帶二價正電荷之雙核釕金屬亞乙烯基化合物進行去質子反應發現了一個有趣的結果，依據第二個金屬上phosphine 取代基推拉電子的特性，可造成不同的環化反應，當第二個金屬上phosphine 取代基是推電子的特性時，化合物16w經由去質子反應可得新型雙金屬五員環錯合物，如是拉電子特性時，先得新型五員環錯合物16x 為中間物，最後再異構化為雙金屬三員環錯合物18x。在化合物13w 和13x 的去質子反應中，我們也發現同樣的結果。
我們也藉由化合物11w 的結構特性，運用類似的反應條件，成功地將系統延伸到三金屬化合物，順利的合成出三核亞乙烯基化合物21。
Treatment of [Ru]-Cl, [Ru] = CpRu(PEt3)2, with phenylacetylene in the presence of KPF6 in methanol affords [Ru]=C=C(H)Ph+ (2) and then deprotonation of 2 by MeONa yields complex [Ru]-C≡C-Ph (3) isolated as yellow solid in high yield. Reactions of 3 with various organic halides in the presence of KPF6 yield corresponding air stable cationic vinylidene complexes [Ru]=C=C(Ph)CH2R+ (4a, R = CH=CH2; 4b, R = CN; 4c, R = C≡CH; 4d, R = CO2Me; 4e, C≡C(SiMe3); 4f, R = Ph; 4g, R = COOEt), respectively, all in high yield. Deprotonation of mononuclear cationic vinylidene complexes of ruthenium [Ru]=C=C(Ph)CH2R (4a, R = CH=CH2, 4b, R = CN, 4f, R = Ph) yields corresponding cyclopropenyl complexes [Ru]-C=C(Ph)CHR (5a, R = CH=CH2, 5b, R = CN, 5f, R = Ph) in high yield. The neutral ruthenium furyl complexes [Ru]-C=C(Ph)CH=C(O)OR, (6d, R = Me; 6g, R = Et) are also prepared by deprotonation of corresponding ruthenium vinylidene complexes containing an ester group at Cγ.
Reaction of the terminal alkynyl group of 4c with [Ru’]-Cl in the presence of KPF6 affords the bisvinylidene complexes [Ru]=C=C(Ph)CH2C(H)=C=[Ru’], (7w, [Ru’] = CpR (PEt3)2; 7x, [Ru’] = CpRu(PPh3)2) which deprotonated to give the alkynyl,vinylidene complexes [Ru]=C=C(Ph)CH2C≡C-[Ru’], (8w, [Ru’] = CpRu(PEt3)2; 8x, [Ru’] =
CpRu(PPh3)2 in the presence of base. Alkylation of complex 8w with various primary alkyl halide affords the corresponding cationic ruthenium bisvinylidene complexes[Ru]=C=C(Ph)CH2C(CH2R)=C=[Ru’], ([Ru’] = CpRu(PEt3)2; 9w, R = CH=CH2; 10w, R = CN; 11w, R = C≡CH; 12w, R = CO2Me; 13w, R = COOEt; 14w, R = Ph; 15w, R = C≡C(SiMe3)). Complexes 9x, 10x, 11x, 12x, 13x, 15x are also successfully obtained by the same synthetic strategy. Deprotonation of the dinuclear dicationic vinylidene complex {[Ru]=C=C(Ph)CH2C(CH2CN)=C=[Ru’]}2+ (10w) by n-Bu4NOH is also followed by a cyclization process, however, yielding the distinctive stable complex 16w containing a five-membered carbocyclic ring ligand which is fully characterized by 2D-NMR analysis and single crystal X-ray diffraction analysis. Deprotonation of {[Ru]=C=C(Ph)CH2C(CH2COOEt)=C=[Ru’]}2+ (13w) similarly gave the stable product 17w containing a bridging ligand also with the same five-membered carbocyclic ring. Interestingly, analogous dinuclear complex 16x with bistriphenylphosphine ligand on one metal, which is prepared in a similar manner
from {[Ru]=C=C(Ph)CH2C(CH2CN)=C=[Ru’]}2+ (10x), however, is unstable undergoing isomerization to give the dinuclear complex 18x containing cyclopropenyl ligand.
The reaction of 11w with [Ru”]-Cl, [Ru”] = CpRu(PEt3 2, gives the trinuclear trisvinylidene complex 21 which undergoes deprotonation to give the trinuclear bisvinylidene acetylide complex 22 characterized by spectroscopic method. Treatment of complex 1 with 1,1 diphenyl-2-propyn-1-ol yields the cationic ruthenium allenylidene complex [Ru]=C=C=C(Ph)2+, (30, [Ru] = CpRu(PEt3)2), in high yield which reacts with Grignard reagent RCH2MgBr in THF affords the neutral ruthenium acetylide complexes [Ru]-C≡C-C(Ph)2CH2R, (31a, R = CH=CH2; 31b, R =
C≡CH). Complexes 30 undergo protonation reactions giving the corresponding vunylidene complexes [Ru]=C=C(H)-C(Ph)2CH2R+, (32a, R = CH=CH2; 32b, R = C≡CH). Unfortunately, no transformation of complexes 32 in solution is observed
indicating the reactivity of complexes 32a and 32b is different from that reported previously.
A number of cationic ruthenium isocyanide complexes [Ru]-CNCH2R+, ([Ru] = CpRu(PEt3)2; 41a, R = Ph; 41b, R = C≡CH) are prepared by alkylation of Ru cyano complex 40 with corresponding alkyl halide. Treatment of complex 41a with base in acetone cause the formation of ruthenium oxazolinyl complex Cp(PEt3)2RuCNCH(Ph)C(Me)2O (43). Complex 41a also reacts with benzaldehyde in CH2Cl2 to afford another ruthenium oxazolinyl complex Cp(PEt3)2RuCNCH(Ph)C(Ph)HO (44).
Subjects
釕金屬
亞乙烯基
雙核
多核
ruthenium
vinylidene
dinuclear
multinuclear
Type
thesis
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