Divinyl-1,1,3,3-tetramethyldisiloxane

Divinyl-1,1,3,3-tetramethyldisiloxane sym-Divinyltetramethyldisiloxane Tetramethyl-1,3-divinyldisiloxane sym-Tetramethyldivinyldisiloxane... 

The TFB-catalyzed dehydrogenative coupling did not occur, nor any transformation whereas the reaction in the presence of platinum 1,3-divinyl-1,1,3,3-tetramethyldisiloxane [Pt(dvs)] resulted in formation of the coupling product in very low yield (<2%) as well as unidentified compounds. 

Step-growth copolymerization of aromatic ketones and 1,3-divinyl-tetramethyldisiloxane is found to be catalyzed by (Ph3p)3RuH2CO. Polymerization occurs by the anti-Markovnikov addition of the C-H bonds, which are ortho to the carbonyl group of the aromatic ketone, across the C-C double bonds of 1,3-divinyltetramethyldisiloxane. 

Bu3P-Pt(0) complex was prepared by the literature procedure 2 FBu3P (32 mg, 0.158 mmol) (Strem Chemicals) was dissolved in platinum(0)-l,3-divinyl-l,l,3,3-tetramethyldisiloxane complex (1.5 mL of xylene solution obtained from Aldrich Chemical Company, Inc., catalog number 47-951-9). The mixture was stirred at 65°C (oil bath) for 5 min and then was slowly cooled to room temperature. This solution could be stored under N2 in the freezer indefinitely. 

Figure 4.3. Stereoregularity of polymers obtained from 1-methyl-l-(naphthyl)-2,3-benzosi-lacyclobut-2-ene (a) racemic, by Pt-l,3-divinyl-l,l,3,3-tetramethyldisiloxane, (b) optically...

CAS 2627-95-4 EINECS/ELINCS 220-099-6 Synonyms Bis (ethenyidimethylsilyl) ether 1,3-Diethenyl-1,1,3,3-tetramethyldisiloxane Disiloxane, 1,3-diethenyl-1,1,3,3-tetramethyl- Disiloxane, 1,1,3,3-tetramethyl-1,3-divinyl- 1,3-Divinyltetramethyldisiloxane... 

While siloxanes are also amenable to ADMET polymerization, they display trends similar to silanes, in that the steric bulk near the reacting olefin prevents productive metathesis [107]. Specifically, l,l,3,3-tetramethyl-l,3-divinyl-disiloxane proved unreactive, while l,3-diallyl-l,l,3,3-tetramethyldisiloxane almost exclusively cyclized. Still, longer di- and tri-siloxane monomers have been shown to polymerize via ADMET. Ring-chain equilibria are well known for polysiloxanes, and some of these polymers degrade over time via intrachain siloxane exchange reactions to form cyclic oligomers [108]. 

Scheme 12 CAChe representation of model poly(tetramethyldisiloxane-divinyl benzene) segment.

Platmum(0)-l,3-divinyl-l,l,3,3-tetramethyldisiloxane (Karstedt catalyst) in xylene and hexachloroplatinic acid (40wt% Pt) as a 1% solution in THF was purchased from Aldrich chemical. 1,1,3,3-Tetramethyldisiloxane (Aldrich) was used without further purification. Divinylbenzene 960 (DVB), which is a mixture of 96% divinylbenzene (meta and para isomers) was purified from the phenolic inhibitor by stirring with 5% by weight basic alumina rmtil the TLC showed the complete removal of inhibitor. The alumina was filtered using Whatman GF/F (0.7 pm). THF was distilled using benzophenone ketyl rmder a nitrogen atmosphere. 

Figure 4. GPC of the product obtained by Ru-catalyzed reaction of acetophenone with 1 J-divinyl-1.1.3 J-tetramethyldisiloxan...

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