Benzylidene ruthenium dichloride

Ring closing olefin metathesis with Bis(tricyclohexyl phosphine benzylidene ruthenium dichloride) Alkene [269, 270]... 

Second-generation ruthenium-carbene complex, (tricyclohexylphosphine-[l,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride),4e was purchased from Strem Chemicals. 

They can be handled analogous to thermosetting resins, and thus the use of highly volatile comonomers, such as ethene or prop-ene is prohibitive. Instead, other vinyl monomers are used. A heat curable formulation uses a mixture of tetracyclododecene, 2-norbomene, 5-vinyl-2-norbomene, and divinylbenzene as reactive components (41). The mixture further contains 3,5-di-ferf-butylhy-droxyanisole as antioxidant and a hybrid catalyst system containing a zirconium based metathesis catalyst and a radical catalyst. The metathesis catalyst is benzylidene (l,3-dimesitylimidazolidin-2-yl-idene)(tricyclohexylphosphine)ruthenium dichloride and the radical catalyst is di-ferf-butyl peroxide. 

Week [4] prepared photoluminescent polynorborene derivatives, (VII), by polymerizing aluminum-8-hydroxyquinoline-functionalized norborene, (VI), using benzylidene (l,3-dimesitylimidazolydin-2-ylidene)-(tricyclohexylpho-sphine)ruthenium dichloride. 

The introduction of molybdenum by R. Schrock (Nobel Prize, 2005) and ruthenium catalyst systems by R. Grubbs (Nobel Prize, 2005), especially the commercially available Grubbs catalysP [bis(tricyclohexylphosphine)benzylidene ruthenium(IV) dichloride]. A, and its second-generation variant, B, shown below, " has led to many RCM applications in organic synthesis. ... 

To a solution of the diene (2.70 g, 11.4 mmol) in CHiCli (300 mL) at reflux under argon was added bis(tricyclohexylphosphine)benzylidene ruthenium (IV) dichloride... 

A catalyst solution is prepared by weighing out benzylidene-bis(tricyclo-hexylphosphine)ruthenium dichloride (0.1 g, 0.1 mmol) in a dry-box under an... 

By monitoring the intensity of the carbonyl absorption it was observed that oxidation of methyl 4,6-0-benzylidene-2-deoxy-a-D-Zt/ ro-hexopyrano-side with chromium trioxide-pyridine at room temperature gave initially the hexopyranosid-3-ulose (2) in low concentration, but attempts to increase this yield resulted in elimination of methanol to give compound 3. However, when methyl 4,6-0-benzylidene-2-deoxy-a-D-Zt/ ro-hexo-pyranoside is oxidized by ruthenium tetroxide in either carbon tetrachloride or methylene dichloride it affords compound 2 without concomitant elimination. When compound 2 was heated for 30 minutes in pyridine which was 0.1 M in either perchloric acid or hydrochloric acid it afforded compound 3, but in pyridine alone it was recoverable unchanged (2). Another example of this type of elimination, leading to the introduction of unsaturation into a glycopyranoid ring, was observed... 

TABLE 1. Ring-opening metathesis polymerization cyclic and acyclic monomers in preparing copolymers nsing catalyst l,3-dimesityl-4,5-dihydroimidazol-2-ylidene) benzylidene-tricyclopentylphosphine ruthenium(II) dichloride. 

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