Synthesis and Reactivity of Coordinatively Unsaturated Dinuclear Ruthenium Bridging Imido Complexes
Synthesis and Reactivity of Coordinatively Unsaturated Dinuclear Ruthenium Bridging Imido Complexes
复制标题
配位不饱和双核钌桥联亚氨基配合物的合成及反应活性
作者：
Takemoto;S.; Kobayashi;T.; Ito;T.; Inui;A.; Karitani;K.; Katagiri;S.; Masuhara;Y.; Matsuzaka;H.
[Cp*Ru(μ-NHPh)]2(Cp*=η5-C5Me5)与CO、t-BuNC、Ph_2S-CH或Me_3SiCCH反应，得到双核Ru桥联亚胺配合物[(Cp*Ru)_2(μ-nPh)(μ-L)](2a，L=CO；2b，L=t-BuNC；2c，L=CH_2；2d，L=CCH_SiMe_3)。2dWITWITT-BUOH质子化得到母体偏亚甲基配合物[(Cp*Ru)2(μ-nPh)(μ-CCH2)](2e)。2E与HOTf或MeOTf反应得到阳离子烷基配合物[(Cp*Ru)2(μ-nPh)(μ-CR)]OTf(2f，R=Me；2g，R=Et)。用Ph_3CBF_4从2c中抽提氢化物得到[(Cp*Ru)_2(μ-nPh)(μ-CH)]BF_4(2 H)。2a−Cand2自由短Ru−N距离(1.876−1.894ó)的X射线结构与Ru−N多重键一致，μ-烷基2f也具有短Ru−C键(1.929(7)和1.914(7)ó)。除了得到简单的路易斯碱加合物[(Cp*Ru)2(μ-nPh)(μ-CO)(PMe3)]和[(Cp*Ru)2(μ-nPh)(μ-CH2)(t-BuNC)2]外，这些亚胺类化合物还提供了一系列新的配体偶联反应。因此，2b经过串联的亚胺−异氰酸酯偶联和C−H活化反应，得到了一个酰胺化的络合物。用2个二烷基取代的亚胺−CO−亚甲基和亚胺−CO−亚甲基偶联，分别得到[{Cp*Ru(CO)2}2(μ-PhNCOCH2)](6)和[{Cp*Ru(CO)}2(μ-PhNCOCCH2)](7)。配合物2c还与2当量的Me3SiCCH发生选择性偶联反应，合成了μ-烯丙基亚胺配合物[(Cp*Ru)2{μ-Me3SiCHCC(SiMe3)C(Me)nPh}](8)。亚胺亚甲基配合物与2当量的炔烃偶联得到[(Cp*Ru)2{μ-HC(R1CCR2)(R2CCR1)nPh}]OTf(9a−c)，产物为Ru−N和Ru−C多键的双炔环加成产物，以及生成的Ruthena和氮杂环丁烯部分的C−C偶联.
[Cp*Ru(μ-NHPh)]2(Cp* = η5-C5Me5) reacted with CO,t-BuNC, Ph2SCH2, or Me3SiCCH to give the dinuclear ruthenium bridging imido complexes [(Cp*Ru)2(μ-NPh)(μ-L)] (2a, L = CO;2b, L =t-BuNC;2c, L = CH2;2d, L = CCHSiMe3). Protonolysis of2dwitht-BuOH produced the parent vinylidene complex [(Cp*Ru)2(μ-NPh)(μ-CCH2)] (2e). Treatment of2ewith HOTf or MeOTf afforded the cationic alkylidyne complexes [(Cp*Ru)2(μ-NPh)(μ-CR)]OTf (2f, R = Me;2g, R = Et). Hydride abstraction from2cwith Ph3CBF4gave the methylidyne complex [(Cp*Ru)2(μ-NPh)(μ-CH)]BF4(2h). X-ray structures of2a−cand2frevealed short Ru−N distances (1.876−1.894 Å) consistent with Ru−N multiple bonds, and the μ-alkylidyne2falso featured short Ru−C bonds (1.929(7) and 1.914(7) Å). In addition to giving simple Lewis base adducts such as [(Cp*Ru)2(μ-NPh)(μ-CO)(PMe3)] and [(Cp*Ru)2(μ-NPh)(μ-CH2)(t-BuNC)2], these imido complexes provided an array of novel ligand coupling reactions. Thus,2bunderwent a tandem imido−isocyanide coupling and C−H activation reaction to give an amidinate complex. Complexes2cand2emediated imido−CO−methylene and imido−CO−vinylidene coupling to give [{Cp*Ru(CO)2}2(μ-PhNCOCH2)] (6) and [{Cp*Ru(CO)}2(μ-PhNCOCCH2)] (7), respectively. Complex2calso underwent a selective coupling reaction with 2 equiv of Me3SiCCH to give the μ-allenylimine complex [(Cp*Ru)2{μ-Me3SiCHCC(SiMe3)C(Me)NPh}] (8). The imido methylidyne complex coupled with 2 equiv of alkynes to give [(Cp*Ru)2{μ-HC(R1CCR2)(R2CCR1)NPh}]OTf (9a−c), a product of double alkyne cycloaddition to the Ru−N and Ru−C multiple bonds and C−C coupling of the resulting ruthena- and azaruthenacyclobutene moieties.