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Drug Discovery

Palladium Catalysts

Sigma-Aldrich offers a range of polymer-supported palladium catalysts for Suzuki and Heck reactions. Just like the traditional palladium catalysts that are used in solution phase, these polymer-supported catalysts produce pure compounds with high yields. Unlike the traditional catalysts, there is no need to add metal scavengers to remove the palladium from the final product. The polymer-supported palladium catalysts can be removed from the final product by simple column chromatography.


 

Application Data

 

Tetrakis(triphenylphosphine) Palladium(0), polymer-bound
Aldrich Catalog # 51157-9


1.  Test Reaction for PS-Pd(0)



Styrene (0.229 ml, 2 mmol), 2-iodoanisole (0.390 ml, 3 mmol), PS-Pd(0) (10 mg, 0.0089 mmol) and triethylamine (0.418 ml, 3 mmol) were mixed in DMF (3 ml). The reaction mixture was stirred at 120°C (oil bath) for 4 hr, cooled to room temperature and evaporated. Water (10 ml) was added and extracted with ether (3x 15 ml). The combined ether phase was evaporated, the residue was purified by flash chromatography ( hexane as eluent) to afford a white solid product (0.391g, 94%).

2.  Test mini-library for Pd(0) Polymer Bound



The following test library of 8 compounds was run using substituted styrene (2 mmol), substituted iodobenzenes (3 mmol), PS-Pd(0) (10 mg, 0.0089 mmol) and Et3N (3 mmol) in 3 ml DMF as described above. The result is listed in the following table.



Yield and purity were obtained based on the column separation and proton NMR.


Product Name Loading Mesh Size Polymer Matrix Product # 
Bis[(diphenylphosphanyl)methyl]amine palladium(II) dichloride, polymer-bound 0.5-1.5 mmol N/g 70-90 PS cross-linked with 2% DVB 64,655-5
Bis(diphenylphosphanyl)methylamine palladium(II) acetate, polymer-bound 0.5-1.0 mmol/g Pd     65,415-9
Dichlorobis(triphenylphosphine)palladium(0), polymer-bound 1.0-2.0 mmol/g 100-200 PS cross-linked with 1% DVB 59,693-0
Palladium(II) acetate triphenylphosphine, polymer-bound 1.0-1.5 mmol/g Pd 200-400 PS cross-linked with 1% DVB 65,416-7
Tetrakis(triphenylphosphine)palladium polymer-bound 0.5-0.9 mmol/g 100-200 PS cross-linked with 2 % DVB 51,157-9

References:

J.M.Pollino and M Weck, Org Lett., 4, 753(2002)
M.Terasawa, K.Kaneda, T.Imanaka and S.Teranishi, J Organomet. Chem., 162, 403(1978)