Borazine reactions with olefins

Borazine and its derivatives are also possible educts to synthesize precursors for Si-B-N-C ceramics. Sneddon and co-workers prepared Si-B-N-C preceramic precursors via the thermal dehydrocoupling of polysilazanes and borazines [7]. A further synthesis route is the hydroboration of borazines. The work group of Sneddon found that definite transition metal reagents catalyze hydroboration reactions with olefins and alkynes to give 5-substituted borazines [8]. Recently, Jeon et al. reported the synthesis of polymer-derived Si-B-N-C ceramics even by uncatalyzed hydroboration reactions from borazines and dimethyldivinylsilane [9]. 

Regents which are active upon irradiation with benzene are olefins and dienes None of these react photochemically with borazine. Recently, the photolysis of benzene at X = 184.9 run with D2 has been shown to produce a small amount of CgHsD (4> = 0.01) This is contrast to the very efficient deuteration at the boron site of borazine (4 = 0.90). Hexafluoroacetone as the absorbing species reacts with borazine to produce a B-alkoxyborazine substitution product. Reaction of this reagent with benzene, on the other hand, involves the CF3 radicals and the products are addition rather than substitution products ss)... 

Transition-metal-catalyzed reactions of borazine with a series of olefins is an alternative method of turning polyborazylenes into processable materials (Eq. 14.2) [17-20]. 

Elemental analyses and the spectroscopic data are consistent with the styrene-co-B-vinylborazine formulations. By adjusting the monomer feed ratios and the initiator concentrations, copolymers ranging in composition from 10 to 90% styrene and molecular weights from -1,000 to >1,000,000 can be producted. The use of these AIBN initiated olefin copolymerization reactions are now being explored as routes to a wide variety of borazine-containing hybrid organic polymers. 

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