Background and overview of the preparation method of bis(1,5-cyclooctadiene)rhodium(I) tetrafluoroborate
Thienopyridine bis(1,5- Rhodium(I)tetrafluoroborate (cyclooctadiene) is a rhodium compound. As a noble metal homogeneous catalyst, rhodium compounds are widely used in important chemical production processes such as hydroformylation, hydrogenation, and oxo synthesis. For example: tris(triphenylphosphine)rhodium chloride is used in industry as an efficient olefin hydrogenation catalyst, dimethylaminopyridine, rhodium acetylacetonate carbonyl, triphenylphosphine rhodium acetylacetone carbonyl, tris(triphenylphosphine)carbonyl Rhodium hydrogen and the like are used as efficient olefin hydroformylation catalysts in olefin hydroformylation industrial units.
Preparation method of di(1,5-cyclooctadiene)rhodium(I) tetrafluoroborate
Preparation method report 1 of di(1,5-cyclooctadiene)rhodium(I) tetrafluoroborate,
10 grams Dissolve rhodium trichloride trihydrate in 100 ml of absolute ethanol and 20 ml of water. Measure 37.4 ml of 1,5-cyclooctadiene in a constant pressure funnel. Under nitrogen replacement protection, start adding 1,5-cyclooctadiene dropwise. After the dropwise addition, the temperature was raised to 82°C and kept stirring for 18 hours. The reaction liquid was concentrated by rotary evaporation, cooled and filtered to obtain 1,5-cyclooctadiene rhodium chloride dimer. Then dissolve all the above solids in 240 ml of methylene chloride and 17.7 ml of 1,5 cyclooctadiene, under nitrogen protection, and slowly add 60 ml of acetone solution containing 7.5 g of silver tetrafluoroborate at 20°C. The temperature was raised to 35°C and reacted for 24 hours, filtered, concentrated by rotary evaporation, filtered, rinsed with methyl tert-butyl ether, and dried under vacuum at room temperature to obtain di(1,5-cyclooctadiene) rhodium (I) tetrafluoroborate 13.8 Gram, the measured metal Rh content is 24.92%, and the theoretical Rh content is 25.30%.
Preparation method report 2 of di(1,5-cyclooctadiene)rhodium(I) tetrafluoroborate,
[Rh(COD) Synthesis of Cl]2: Add 1.0g RhCl3.3H2O to a 100mL two-necked flask equipped with a reflux condenser, vacuum, add 2.0mL COD (1,5-cyclooctadiene) and 30mL EtOH under N2 protection, and heat to reflux 4h. After the reaction was completed, it was naturally cooled to room temperature, and the yellow solid was obtained by suction filtration. After rinsing with anhydrous ether, it was dried under vacuum at room temperature. The product yield was 78%.
Synthesis of bis(1,5-cyclooctadiene)rhodium (I) tetrafluoroborate: Under N2 protection, add 275mg (0.56 mmol) [Rh(COD)Cl]2, 0.17mL (1.38mmol) COD and 5mL CH2Cl2; dissolve another 250mg (1.28mmol) AgBF4 in 5mL acetone and transfer it to a constant pressure dropping funnel. Add the silver fluoroborate solution dropwise to the two-necked bottle within 5 minutes at room temperature, and continue stirring for 15 minutes. A large amount of white silver chloride precipitates will form, and the solution will turn dark red. After the reaction, the reaction solution was left to stand. After the precipitation dropped, the resulting clear liquid was transferred to about 50 mL of anhydrous and oxygen-free ether under stirring. An orange-yellow precipitate immediately formed. Leave it to stand overnight, filter it, and dry it under vacuum to obtain a brown color. Red powdery solid, product yield 80%, melting point 206-208 ℃.
References
[1] From Faming Zhuanli Shenqing, 105585596, 18 May 2016
[2] From Faming Zhuanli Shenqing, 103214520, 24 Jul 2013
