Copper norbornadiene

As well as [2-H]-addition products, in copper-catalyzed reactions with norbornadiene and bicyclo[2.2.1]heptene (norbornene) as reactive alkenes, [2 + 2] products are also formed. The selectivity of the reaction depends on the reaction temperature. At — 20°C a 90-95% selectivity for the [2 + 2] addition can usually be obtained with copper(I) chloride/triphenyl-phosphane or triphenyl phosphite als catalyst.At higher reaction temperatures, products... 

A mixture of trans-3,5- and exo-cw-3,5-dichloro-tricyclo[2.2.1.0 ]heptanes 26 and 27 was obtained in excellent total yields on chlorination of norbornadiene with copper(II) chloride, thal-lium(III) chloride tetrahydrate and antimony(IV) chloride. The use of other halogenating agents such as thionyl chloride, chlorine and phosphorus(V) chloride leads to appreciable amounts of exo-5-.iyn-l- and ex o-cw-S.b-dichloronorbornenes in addition to 26 and 27. ... 

The chlorination of norbornadiene with copper(II) chloride, " " chlorine, phenyliodonium dichloride, gold(III) chloride, and molybdenum(V) chloride have been reported to yield predominantly 3,5-dichlorobicyclo[2.2.1.0 ]heptanes 11 and The results of the reaction with other chlorinating agents are summarized in Table 3. 

A detailed study of the photochemical cyclization of norbornadiene to quadricyclane using aryl phosphine copper(I) halides has been reported. The quadricyclane (144) is formed on irradiation of the norbornadiene (145) at 366 nm. The quantum yield (0.68) for the process is high. The influence of triplet sensitizers ( metal complexes, biacetyl and acetophenone) were found to be less efficient ( ct> = 0.1). The authors suggest that the lowest singlet state of norbornadiene is much more reactive than the triplet state. ... 

For olefin Ti-complexes, copper(II) halides as fine powders react with butadiene, norbornadiene, cyclooctadiene or dicyclopentadiene to give the corresponding olefin complex (2-4). Some olefins readily form silver nitrate complexes (2-5) in an aqueous or alcoholic solution. 

Franceschi, F., Guardigli, M., Solari, E., Floriani, C., Chiesi-ViUa, A., and Rizzoli, C., Designing copper(I) photosensitizers for the norbornadiene-quadricyclane transformation using visible light an improved solar energy storage system, Inorg. Chem., 36,4099—4107, 1997. 

Onishi, M. and Hiraki, K., Phosphine steric effects on the catalytic activities of a few chloro(tertiary phosphine) copper(I) oligomers in photoisomerizations of norbornadiene and tra s-stilbene, Inorg. Chim. Acta, 202, 27-30, 1992. 

Basu, A., Saple, A.R., and Sapre, N.Y., Di-2-pyridil ketone complexes of copper (I) efficient photocatalysts for norbornadiene-quadricyclane conversion, /. Chem. Soc., Dalton Trans., 1797-1799, 1987. 

Rosi, M., Sgamelotti, A., Francheschi, F., and Floriani, C., Use of norbomadiene in solar energy storage theoretical study of a copper(l) photosensitizer for the norbornadiene-quadricyclane transformation, fnorg. Chem., 38,1520-1522,1999. 

---