Cyclooctadienes with acetone

Into a Schlenk tube was placed Auf 1,5-cyclooctadiene)-nickeI(0) (2.6 mmol), 2,2 -bipyridyl (2.6mmol), 1,5-cyclooctadiene (0.2ml), DMF (4ml), and toluene (8 ml). The reaction mixture was heated to 80°C for 0.5 h under argon. The dibromide comonomers 623 and 634 dissolved in degassed toluene (8 ml molar ratio of dibromides to nickel complex 0.65) were added under argon to the DMF-toluene solution and the polymerization maintained at 80°C for 3 days in the dark. 2-Bromofluorene (molar ratio of dibromides to monobromide 0.1) dissolved in degassed toluene (1ml) was added and the reaction continued for 12 h. The polymers were precipitated by addition of the hot solution dropwise to an equivolume mixture of concentrated HC1, methanol, and acetone. The isolated polymers were then dissolved in toluene or dichlor-omethane and reprecipitated with methanol/acetone (1 1). The copolymers were dried at 80°C in vacuo. The isolated yields of copolymers 240a-c were 79-85%. 

The ruthenium catalysts were prepared at room temperature by reaction of [Ru(l,5-cyclooctadiene)(2-methylallyl)2] with ligand P P (1.1 equiv) in acetone (1 mL). Methanolic HBr (2.2 equiv) was added dropwise to the solution which... 

A glass reactor was charged with W-(2,6-diisopropylphenyl)-2-(2,6-diisopropyl-phenylimino)propanamide-benzyltrimethylphosphine nickel (20 pmol) in toluene, bis(l,5-cyclooctadiene)-nickel (50p,mol) in toluene, and 5-norbomen-2-ol (4.49 mmol) were dissolved in toluene, and additional toluene (18.45 g) added so that the total volume of the toluene solution was 30 ml. The glass reactor was then sealed and ethylene continuously fed into the reactor at 100 psi and the mixture stirred for 20 minutes at 20°C. Acetone was then added to quench the polymerization and die precipitated polymer isolated by filtration, dried, and 0.518 g of product isolated. The activity of the catalyst was 105 kg mol lh 1. 

Nonconjugated dienes and polyenes have triplet photochemistry which may be considered to arise from intramolecular interaction of one excited double bond with an isolated ground-state double bond. For example, the photocyclization of enrfo-dicyclopentadiene can be effected using acetone as a sensitizer.286 Other more flexible 1,5-dienes, when sensitized to triplet states, cross couple to yield bicyclo[2.1.1]-hexane structures. For instance, triplet mercury atoms convert both 1,5-hexadiene and 1,5-cyclooctadiene to such structures.267 Irradiation of the cyclooctadiene in the presence of cuprous chloride produces the tricyclo derivative in good yield266 but recent evidence again indicates that this latter reaction may proceed via free-radical intermediates.269... 

A number of compounds have been proposed as useful intermediates for the synthesis of ruthenium(II) complexes. Singleton and co-workers have investigated [Ru(diene) (N2H4)4]2+ in this respect. Reaction of the cyclooctadiene compound with bpy in acetone yields [Ru(cod)(bpy)2]2+ u8. With some ligands complete substitution resulted119. They later claimed120 [Ru(H)(cod)(NH2NMe2)3]+ to be the most versatile precursor known at that time. 

The previously reported4 procedure, which is a technique of general utility, involves the reaction of dichloro(l,5-cycloocta-diene)palladium(II) with a solution of sodium bromide in acetone. The following procedure gives comparable yields and eliminates the need for the preparation of the dichloro intermediate. Bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene) may be substituted in the following procedure for the 1,5-cyclooctadiene to yield (bicyclo[2.2.1]hepta-2,5-diene)dibromopalladium(II). 

The complexes (l,5-cyclooctadiene)(2,4-pentanedionato)-palladium(II) and platinum(II) tetrafluoroborate are air-stable solids, soluble in polar organic solvents such as chloroform, methylene chloride, acetonitrile, acetone, or methanol but insoluble in nonpolar solvents such as alkanes, benzene, or ether. Their solutions in acetone have conductivities typical of 1 1 electrolytes. Their proton magnetic resonance spectra (in CDC13 solutions, internal tetramethylsilane reference at 60 MHz.) show peaks due to coordinated cyclooctadiene at 3.78 and 6.7-7.4r (Pd) and at 4.25 and 6.9-7.6r (Pt) and due to the chelated /3-diketone at 4.39 and 7.88r (Pd) and at 4.15 and 7.81r (Pt) with the expected area ratios. In the spectrum of the platinum compound coupling with the 95Pt isotope (33 %... 

Chloro(l,5-cyclooctadiene) (triphenylarsine)platinum(II) tetrafluoroborate is a white, air-stable solid. It is sparingly soluble in polar organic solvents and insoluble in nonpolar ones. A 10-3 M solution in acetone shows a conductivity characteristic of a 1 1 electrolyte.1 Its proton magnetic resonance spectrum (in liquid sulfur dioxide solution, at 60 MHz., with internal tetramethylsilane reference) shows bands due to the coordinated olefin at 3.59 [two protons 55 Hz.], 5.01 [two... 

The oligomerization and cooligomerization of conjugated dienes are representative reactions that proceed via transition-metal Jt-allyl intermediates. When (CsMesjRuCljt/ -butadiene) in dichloromethane was treated with an acetone solution of an equimolar amount of silver trifluoromethanesulfonate (AgOTf) in the presence of excess butadiene at ambient temperature, after which the mixture was allowed to react with carbon monoxide (1 atm), a cationic 1,5-cyclooctadiene carbonyl complex, [(C5Me5)Ru(CO)( -l,5-C8Hi2)]OTf, was isolated in 95% yield (Eq. 

The diolefin complexes are much more stable than monoolefin complexes and can be prepared by the direct reaction of olefin with Na2PdCl4 in various solvents. The 1,5-cyclooctadiene (COD) complex is prepared by treating COD with Na2PdCl4 in acetone, acetic acid, water, or ethanol 34, 87) ... 

Rhodium trichloride trihydrate (1.0 g, 3.8 mmol) and 1,5-cyclooctadiene (2 ml, ca. 16 mmol) are added to ethanol (30 ml), and the mixture is stirred and refluxed for 3 h. After the mixture is cooled to room temperature, the orange solid is filtered, washed with ethanol, dried, and recrystallized from acetic acid. The crystals are dried under vacuum. Yield 0.56 g (60 %). The crystals are stable under air. Soluble in dichloromethane, chloroform, acetic acid, and acetone, slightly soluble in ether, methanol, ethanol, and benzene, and insoluble in water. 

Iridium trichloride (2.0 g, 5.7 mmol) is added to a mixture of 95 % ethanol (34 ml), water (17 ml), and 1,5-cyclooctadiene (6 ml). L nder nitrogen atmosphere the solution is stirred and refluxed for 24 h, during which lime the product separates as brick-red solid. After the mixture is cooled to room temperature, the solid is filtered and washed with ice-cold methanol. The orange-red solid is dried under vacuum. Yield 1.5 g (72 %). The compound is air-stable. Soluble in chloroform and benzene, sparingly soluble in acetone, and insoluble in ether. 

A. (1a,2tt,Sa,6a)-2,6-Dichloro-9-thiabicyclo[3.3.1]nonane (1). (Caution Preparation A should be carried out in a well-ventilated hood). A dry, 2-L, four-necked, round-bottomed flask is equipped with a sealed mechanical stirrer (Note 1), 1-L pressure-equalizing tunnel fitted with a drying tube, low temperature thermometer, and a nitrogen inlet. The flask is charged with 125 mL (1.02 mol) of 1,5-cyclooctadiene (Note 2) and 1 L of reagent dichloromethane, cooled to -50 to -60 C using an external acetone-dry ice bath, and the solution placed under a slow stream of dry nitrogen. To... 

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