反応 #456106

反応方程式

norbornene

isobutylene

methylene chloride

THF

methylene chloride

methylene chloride

methanol

norbornene

→

5-norbornene-carboxylic acid

反応条件

後処理

1. 1
   その他the solution was degassed under argon atmosphere
2. 2
   その他A 10 ml glass vial equipped with a Teflon® coated stir bar
3. 3
   その他The catalyst solution was prepared
4. 4
   その他Immediate precipitation of the silver chloride salt
5. 5
   ろ過which was filtered
6. 6
   その他to obtain a clear yellow solution
7. 7
   workup.ADDITIONThe active yellow catalyst solution was added to the monomer solution via a syringe at 50° C.
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   温度No appreciable increase in viscosity
9. 9
   ろ過the solution was filtered through a 0.5 μ
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    ろ過filter
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    濃縮concentrated
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    workup.DISSOLUTIONThe resulting viscous solution was dissolved in methanol
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    その他precipitated into methanol/water mixture
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    その他to obtain a white solid
15. 15
    その他yield (23%)
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    その他to be thermally stable to about 155° C.
17. 17
    その他by 290° C.

実験手順

To a 25 ml glass vial equipped with a Teflon® coated stir bar was added 3.06 g (12.8 mmole) of pure of bicyclo[2.2.1]hept-5-ene-exo,exo-2,3-dicarboxylic acid diethyl ester, 2.5 g (12.8 mmole) of t-butylester of norbornene, followed by 15 ml of freshly distilled methylene chloride and 10 ml of methanol, and the solution was degassed under argon atmosphere. A 10 ml glass vial equipped with a Teflon® coated stir bar was charged with 0.0188 g (0.052 mmol) of allylpalladium chloride dimer (to give a monomer to catalyst ratio of 500/1) and 2 ml of methylene chloride. Into another 10 ml glass vial was charged with 0.0357 g (0.104 mmol) of silver hexafluoroantimonate and 2 ml of methylene chloride. The catalyst solution was prepared by mixing the allylpalladium chloride dimer solution with silver hexafluoroantimonate solution inside the dry box. Immediate precipitation of the silver chloride salt was observed, which was filtered, to obtain a clear yellow solution. The active yellow catalyst solution was added to the monomer solution via a syringe at 50° C. and the reaction mixture was allowed to stir for 16 hours at room temperature. No appreciable increase in viscosity was observed and the solution was filtered through a 0.5 μ filter, concentrated using a rotovap. The resulting viscous solution was dissolved in methanol and precipitated into methanol/water mixture to obtain a white solid yield (23%). The molecular weight was observed to be Mn=15,700 g/mole and Mw=32,100 g/mole (GPC in THF, polystyrene standards). 1H NMR indicates the presence of both methyl and t-butyl ester of norbornene. Thermogravimetric analysis (TGA) under nitrogen (heating rate 10° C./min.) showed the polymer to be thermally stable to about 155° C. and then to exhibit approximately 20 wt. % loss by 290° C. (indicating clean loss of the t-butyl groups as isobutylene to afford the homopolymer of 5-norbornene-carboxylic acid) and then degradation of the polymer at around 450° C.

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