Ge-Branched and Connectivity

Suzuki et al.[57 explored the Pd-catalyzed ring-opening of the monomer 5,5-dimethyl-6-ethenylperhydro-l,3-oxazin-2-one to give a hyperbranched polyamine. The polymerization was conducted at ambient temperature in THF and catalyzed with Pd2(dba)3-2 dppe, affording after the evolution of carbon dioxide, the desired hyperbranched polyamine. NMR spectroscopy confirmed the high yield conversion of the monomer. The degree of branching was ascertained (from NMR data) as the ratio of tertiary amine units to the total of secondary and tertiary moieties. 

Mathias et al. also reported the preparation of a rigid four-directional core for the construction of dendrimers possessing sterically dispersed functionality. Pathways for 

Muzafarov, Golly and Moller 646 have prepared similar poly(alkoxysilanes) that are easily hydrolyzed under acidic conditions and are thus biodegradable. Additional branched organosilicon polymers of interest include those of Ishikawa et al. fi4c  

Saunders, K. C. Frisch, Polyurethanes Chemistry and Technology, Wiley, New York, 1962, pp. 118-121. 

Percec, J. Heck, G. Johansson, D. Tomazos, M. Kawasumi, J. Macromol. Sci., PureAppl. Chem. 1994, A31, 1031. 

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