Cooligomers

R. Bacskai and A. H. Schroeder. Alkylaniline/formaldehyde cooligomers as corrosion inhibitors. Patent US 4778654,1988. 

S. Huang, J. M. Tour. Rapid solid-phase synthesis of conjugated homooligomers and [AB] alternating block cooligomers of precise length and constitution, J. Org. Chem. 1999, 64, 8898-8906. 

However, this is not always the case. Excess of K - K has been found to occur during the initial stage of the copolymerisation when the cooligomer chain bound to the metal is still soluble and catalysis occurs in the homogeneous phase [36]. This may also occur when protonolysis involves H20 in place of MeOH, with formation of a Pd - OH+ species, which regenerates Pd - H+ by insertion of CO to Pd - COOH+ followed by C02 evolution. Thus in each catalytic cycle one molecule of CO is not incorporated into the polymer chain, but is consumed as C02 ... 

Sen A (ed.) (2003) Catalytic Synthesis of Alkene-Carbon Monoxide Copolymers and Cooligomers. Kluwer Academic, Dordrecht... 

Nozaki, K. In Catalytic Synthesis of Alkene-Carbon Monoxide Copolymerrs and Cooligomers, Chap. 7, Sen, A. (Ed.), Kluwer Academic Publishers, Dordrecht, 2003. 

Irregular oligomer, the molecules of which are derived from only one species of monomer but which display a variety of structural features more appropriate for description in cooligomer terms. 

Air-stable silole-thiophene alternating 1 1 cooligomers (up to a seven-ring system) have been prepared by nickel(0)-promoted intramolecular cyclization of the corresponding thiophene-(l,6-heptadiyne) alternating cooligomers with hydrodisilanes54b173, as illustrated in Scheme 27. 

Functional siloles have found applications in the elaboration of silole-containing tt-conjugated systems. Because of its unique electronic properties, the introduction of a silole component or a silole cooligomer into an unsaturated chain should be a promising route to novel --electronic materials and, in this connection, the preparation of new heterocyclopentadiene monomeric precursors remains a current challenge. 

Three isomers of the substituted cyclobutanes 33, 34 and 35 are obtained by the [2+2] cycloaddition of isoprene, and separated at low temperature from other cooligomers without undergoing Cope rearrangement. When the mixture was subjected to hydroboration and oxidation, the alcohol 37 was obtained from the isomer 34, and easily separated from 35 and the diol 36. The alcohol 37 is a pheromone called grandisol [11]. Although overall yield was 15%, this is the shortest synthetic route to this pheromone. 

Several linear cooligomers of butadiene are prepared with alkenes and alkynes. Commercially important 1,4-hexadiene (103) is prepared by the reaction of ethylene and butadiene catalysed by Ni [40], Fe [41] and Rh [42], The experiment carried out using deuterated ethylene (100) supports the mechanism that the insertion of butadiene to M—H forms the 7i-allyl complex 99. Insertion of ethylene (100) to 99 gives 101, and its -elimination affords the cooligomer 102, tetradeuterated at C-1,1,2,6 of 103. 

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