1,5-Cyclooctadiene halogenation

Electrophylic halogenation of 9-oxabicyclo[3.3.l]nona-2,6-diene (139), a heteroanalog of 39, in the presence of water and its epoxidation with performic acid results in ring closure to 4,8-disubstituted 2,6-dioxaada-mantane derivatives.168 4,8-Dibromo-2,6-dioxaadamantane is also prepared from the syn-dibromide of 1,5-cyclooctadiene.169... 

The presence of halogen atoms appears to exert little, if any, effect on catalyst activity, but it can influence the course of the metathesis reaction. Vinylic halides are unreactive, as exemplified by the ring-opening polymerization of l-chloro-l,5-cyclooctadiene, which afforded a perfectly alternating copolymer of butadiene and chloroprene (7/2) via polymerization exclusively through the unsubstituted double bond. 

Dienes such as norbomadiene, 1,5-cyclooctadiene and Dewar hexamethylbenzene will form mononuclear chelate complexes such as PtX2(diene) (X = halogen).645 Alkene isomerization may occur. Thus whereas complexes of 1,4- and 1,5-cyclooctadiene have been obtained which involve no isomerization,646,647 under different experimental conditions phosphine complexes of... 

Successive treatment with either SC12 or S2CI2 and SOCl2 converts 1,5-cyclooctadiene into 2,6-dichloro-9-thiabicyclo-[3.3.1]nonane 466. Both halogen atoms can be replaced by a wide variety of nucleophiles <2001JOC4386>. Following hydrolysis to the 2,6-diol, Swern oxidation affords the 2,6-dione (Scheme 160) < 19980SC692>. 

Coordination catalysts of formula (I), where M is Pd, Q is an alkyl, S is a halogen, R1 is H or an alkyl (1-4 carbon atoms), preferably a methyl group, and R2 is a hydrocarbyl (1-4 carbon atoms), preferably a methyl group, may be made by the reaction of the corresponding 1,5-cyclooctadiene (COD) Pd complex with the appropriate diimine. When M is Ni, (I) can be made by the displacement of another ligand, such as a dialkylether or a polyether such as 1,2-dimethoxyethane, by an appropriate diimine ... 

Carbene carbon. Carbonyl carbon. COD = 1.5-cyclooctadiene. CioHja = cyclopen tad iene dimer. Carbon trans to phosphorus or arsenic. Carbon trans to halogen or methyl. Phenyl carbon. Cyanide carbon. 

Fluoro complexes of Rh(i)-containing cyclooctadiene were reported and the reactivity of the Rh-F bond studied, showing significant differences from other Rh-halogen bonds. ... 

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