Ruthenium-Catalyzed Dimerization of 1,1-Diphenylpropargyl Alcohol to a Hydroxybenzocyclobutene and Related Reactions

Nguyen, Hoang; Tashima, Naoto; Ikariya, Takao; Kuwata, Shigeki

doi:10.3390/inorganics5040080

Cited by 3 publications

(4 citation statements)

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“… 39 The formation of alkylidenebenzocyclobutenyl alcohols has also been observed. 40 Catalysts for the cycloisomerization of enynols are even more rare, 41 and as far as we know, have not been applied to diols.…”

Section: Resultsmentioning

confidence: 99%

“…In contrast to 6 , the majority of them lead to products resulting from a head-to-head ( E )-coupling and in some cases, from a head-to-tail dimerization . The formation of alkylidenebenzocyclobutenyl alcohols has also been observed . Catalysts for the cycloisomerization of enynols are even more rare, and as far as we know, have not been applied to diols.…”

Section: Resultsmentioning

confidence: 99%

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Silyl-Osmium(IV)-Trihydride Complexes Stabilized by a Pincer Ether-Diphosphine: Formation and Reactions with Alkynes

et al. 2022

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Complex OsH 4 {κ 3 -P,O,P-[xant(P i Pr 2 ) 2 ]} (1) activates the Si−H bond of triethylsilane, triphenylsilane, and 1,1,1,3,5,5,5-heptamethyltrisiloxane to give the silyl-osmium(IV)trihydride derivatives OsH 3 (SiR 3 ){κ 3 -P,O,P-[xant(P i Pr 2 ) 2 ]} [SiR 3 = SiEt 3 (2), SiPh 3 (3), SiMe(OSiMe 3 ) 2 (4)] and H 2 . The activation takes place via an unsaturated tetrahydride intermediate, resulting from the dissociation of the oxygen atom of the pincer ligand 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene (xant-(P i Pr 2 ) 2 ). This intermediate, which has been trapped to form OsH 4 {κ 2 -P,P-[xant(P i Pr 2 ) 2 ]}(P i Pr 3 ) (5), coordinates the Si−H bond of the silanes to subsequently undergo a homolytic cleavage. Kinetics of the reaction along with the observed primary isotope effect demonstrates that the Si−H rupture is the rate-determining step of the activation. Complex 2 reacts with 1,1-diphenyl-2-propyn-1-ol and 1-phenyl-1-propyne. The reaction with the former affords Os{C�CC(OH)Ph 2 } 2 {�C�CHC(OH)Ph 2 }{κ 3 -P,O,P-[xant(P i Pr 2 ) 2 ]} (6), which catalyzes the conversion of the propargylic alcohol into (E)-2-(5,5-diphenylfuran-2(5H)-ylidene)-1,1-diphenylethan-1-ol, via (Z)-enynediol. In methanol, the hydroxyvinylidene ligand of 6 dehydrates to allenylidene, generating Os{C�CC(OH)Ph 2 } 2 {�C�C�CPh 2 }{κ 3 -P,O,P-[xant(P i Pr 2 ) 2 ]} (7). The reaction of 2 with 1-phenyl-1-propyne leads to OsH{κ 1 -C,η 2 -[C 6 H 4 CH 2 CH�CH 2 ]}{κ 3 -P,O,P-[xant(P i Pr 2 ) 2 ]} (8) and PhCH 2 CH�CH(SiEt 3 ).

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Silyl-Osmium(IV)-Trihydride Complexes Stabilized by a Pincer Ether-Diphosphine: Formation and Reactions with Alkynes

et al. 2022

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“…Ruthenium complexes are known to form allenylidene complexes from propargylic alcohols [16], and these species can potentially function as intermediates for the substitution of the OH group of propargylic alcohols by nucleophiles [1,2,3]. Consequently, rutheniumcatalyzed transformations of propargylic alcohols have been intensively investigated by us [17,18,19,20] and others [1,3,14,15,21], and have resulted in a variety of catalyst systems for the transformation.…”

Section: Introductionmentioning

confidence: 99%

Ruthenium complexes of the general formula [RuCl2(PHOX)2] as precatalysts in propargylic substitution reactions

Jourabchian

Jurkowski

Bauer

2018

Catalysis Communications

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“…Nguyen, Tashima, (the late) Ikariya and Kuwata report on the room temperature dimerization of 1,1-diphenylpropargyl alcohol mediated by the organometallic Ru(II) complex [Ru(Cp*)Cl(diene)]-diene = 1,5-cyclooctadiene (cod) or isoprene, leading to the new crystalline product alkylidenebenzocyclobutenyl alcohol [28]. This product is formed via the intermediacy of facile selective aromatic C-H activation on one of the arene rings within the substrate, as revealed by labelling studies and control experiments to exclude other pathways.…”

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From Mechanisms in Homogeneous Metal Catalysis to Applications in Chemical Synthesis

2018

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Man-made homogeneous catalysis with the aid of transition metal compounds looks back on a long history of almost one hundred years. Still, more detailed insight into the underlying mechanisms is warranted. The knowledge of how transition metals with their specific/characteristic properties, such as oxidations states, redox chemistry, spin states, kinetics, and coordination preference will contribute to these processes paving the way to optimize existing processes, and to finding new exciting organic, inorganic, and organometallic transformations and to broaden the substrate scope through catalyst design. This special issue collects very recent mechanistic insight from experimental, theoretical, and mixed experimental-theoretical approaches.At the very end of the 19th century, Alfred Werner established the basis of our modern understanding of (transition) metal complexes [1]. When Otto Roelen discovered and developed the hydroformylation reaction (or Oxo Process) in the late 1930s, probably the first milestone in homogeneous catalysis, serendipity played an important role [2,3]. A deeper understanding of the specific interactions of ligands and metals came only later with the development of binding concepts such as the ligand field theory and the molecular orbital theory, e.g., the Dewar-Chatt-Duncanson model, which was developed in the 1950s for the binding of olefins to transition metals [4]. Originally dedicated to the binding situation of the complex anion of the Zeise salt [PtCl 3 (ethene)] -, it soon became clear that homogeneously metal-catalyzed transformations of olefins can be described and understood using this concept [4][5][6][7]. Probably the most prominent examples of such olefin complexes are the Pd derivatives of the Zeise anion [PdCl 3 (olefin)] − , which were the pivotal species of today's technically most important organocatalytic process, the Wacker Process (or Wacker Oxidation), which was developed starting in the 1950s [7][8][9][10].About 80 years after Roelen's hydroformylation, on a list of recently identified "holy grails" in chemistry "perfect catalysis" is prominently in the top ten [11] and homogeneous transition metal catalysis provides the basis for many desired transformations, e.g., in C-H aminations, in site-selective bond activations, for the functionalization of alkanes or in oxidative couplings yielding complex target molecules. Even since the rise of "metal-free" organo-catalysis at the beginning of our millennium and its enormous impact on organic transformations, the meanwhile established "classical" (transition) metal mediated applications reside as solid pillars in the toolbox for chemical synthesis [12][13][14]. Recent Nobel Prizes in chemistry, i.e., 2010 to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki, 2005 to Yves Chauvin, Robert H. Grubbs and Richard R. Schrock, as well as 2001 to William S. Knowles, Ryoji Noyori and K. Barry Sharpless [14,15] clearly highlight homogeneous transition metal catalysis as an outstanding discipline, crucial for various are...

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Ruthenium-Catalyzed Dimerization of 1,1-Diphenylpropargyl Alcohol to a Hydroxybenzocyclobutene and Related Reactions

Cited by 3 publications

References 38 publications

Silyl-Osmium(IV)-Trihydride Complexes Stabilized by a Pincer Ether-Diphosphine: Formation and Reactions with Alkynes

Silyl-Osmium(IV)-Trihydride Complexes Stabilized by a Pincer Ether-Diphosphine: Formation and Reactions with Alkynes

Ruthenium complexes of the general formula [RuCl2(PHOX)2] as precatalysts in propargylic substitution reactions

From Mechanisms in Homogeneous Metal Catalysis to Applications in Chemical Synthesis

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