Regiospecific oligomerization

The reaction is also utilized for cross-linking between vinyl-substituted siloxanes and oligomeric hydrosilanes in the production of room-temperature vulcanizable sihcone rubber. Reaction can be carried out without solvents, but common solvents such as benzene, toluene, dichloromethane, THF, and acetonitrile can be employed as well. A wide variety of 1-alkenes are hydrosilated regiospecifically to give... 

Chitin was prepared by the catalysis of chitinase. Incubation of a chitobiose oxazoline monomer with chitinase form bacillus sp. in phosphate buffer afforded chitin in quantitative yield (122). Using regiospecific 3-0- and/ or 3 -0-methylated derivatives of a chitobiose oxazoline as new substrate monomers, 3-0-methylated chitin oligomers were produced by enzymatic oligomerization using chitinase (123). 

It was found that 16 exhibited regiospecific oligomerization of propene, 1-butene, and 1-pentene to yield linear atactic polymers as head-to-tail coupling of monomer units is favored by this catalyst [33]. The polymer chain grows by a P-hydride elimination mechanism, which competes with phosphine coordination, leading to a relatively... 

---