Polymerization of cyclobutene

Surprisingly there have been no reports of late transition metal-catalyzed addition polymerization of cyclobutenes. Since the homopoiymerization of cyclobutene using metallocene catalysts is exemplified in the literature [16] it is only a matter of time before a report of a cationic palladium or nickel catalyst for the polymerization appears in the literature. 

Under similar conditions as those described by Rinehart for butadiene polymerization, Natta et al. investigated the polymerization of cyclobutene. With low conver-... 

Most V-based catalysts of the Ziegler-Natta type cause double-bond opening (addition polymerization) rather than ROMP of cycloalkenes. For example, V(acac)3/Et2AlCl causes only Ziegler-Natta-type addition polymerization of cyclobutene (Natta 1963) and its copolymerization with ethene (Natta 1962). 

Natta, G DaH Asta, G Mazzanti, G Molroni, G Stereospecific polymerization of cyclobutene. Maktomol. Chem. 1963, 69, 163-179. 

Natta, G Dall Asta, G Porri, L. Polymerization of cyclobutene and 3-methylcyclobutene by RUCI3 in polar protic solvents. Makromol. Chem. 1965, 81, 253-257. 

Cyclic alkenes such as cyclobutene, cyclopentene, and norbornene can be polymerized by double-bond opening with metallocene/methylalumoxane or late transition catalysts [548-551]. The activities for the polymerization of cyclobutene and cyclopentene are high, whereas the activity of norbornene is significantly lower. The melting points are... 

For the polymerization of cyclobutene, Natta and coworkers [37] reported binary catalytic systems containing titanium, vanadium, chromium, and tungsten to be the most active, those of molybdenum less active, and systems derived from cobalt, iron, manganese, and uranium totally inactive. Catalysts based on vanadium and chromium yield preferentially polycyclobutylene by addition polymerization, those with molybdenum and tungsten give polybutenamer by ring-opening... 

Polymerization of cyclobutene has been carried out using a wide range of catalytic systems based on transition metal salts and organometallic compounds. Depending on the catalytic system employed, polycyclobutylene or polybutenamer or both types of polymers have been obtained [Eq. (5)]. 

Relatively few data are published concerning the polymerization of cyclobutene, cyclopentene, cyclohexene, or cyclooctene and their substituted derivatives in the presence of cationic initiators [1], Cyclopentene and cyclohexene proved to be unreactive toward AICI3 at low temperatures (—20°C) in ethyl chloride, but they give dimers, trimers, and tetramers as well as higher polymers with BF3 and hydrogen fluoride [9, 10]. On the other hand, copolymerization of cyclohexene with styrene and a-methylstyrene in the presence of AICI3... 

Wu, Z., Wheeler, D.R., and Grubbs, R.H. (1992) Living ring-opening metathesis polymerization of cyclobutene The thermodynamic effect of a reversibly binding ligand. Journal of the American Chemical Society, 114,146-151. 

Polyacetylene itself is not processible. A precursor route (the Durham route) overcomes this drawback. Ring-opening metathesis polymerization of cyclobutene... 

Durham" polyacetylene and involves the ring-opening metathesis polymerization of cyclobutene derivatives followed by a thermal retro-Diels Alder reaction to perform the... 

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