2-Dicyclohexylphosphino-2',4',6'-triisoprophylbiphenyl → HCID 54591522, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 500 mg (1.01 mmol) of the compound from Example 10A, 514 mg (1.51 mmol) of the compound from Example 9A, 92 mg (0.101 mmol) of tris(dibenzylideneacetone)dipalladium(0), 96 mg (0.202 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-Phos) and 194 mg (2.02 mmol) of sodium tert-butoxide in 10 ml of toluene was heated to 80° C. under argon in a microwave oven (Biotage Initiator, dynamic control of the incident power) for 3 h. After cooling to RT, 100 ml of water were added to the reaction mixture, which was extracted three times with approx. 100 ml each time of ethyl acetate. The combined organic extracts were washed successively with water and saturated sodium chloride solution, dried over anhydrous magnesium sulphate, filtered and finally freed of the solvent on a rotary evaporator. The resulting crude product, which was the corresponding silyl-protected intermediate, was purified by means of MPLC (approx. 70 g of silica gel, eluent: cyclohexane→5:1 cyclohexane/ethyl acetate). Subsequently, this product was dissolved in 3.5 ml of THF, and 3.5 ml (3.5 mmol) of a 1 M solution of tetra-n-butylammonium fluoride (TBAF) in THF were added. After this mixture had been stirred at RT for 20 min, it was concentrated on a rotary evaporator. The title compound was isolated by means of MPLC (approx. 20 g of silica gel, eluent: 2:1→1:3 cyclohexane/ethyl acetate). After concentration and drying, the product was once again stirred with pentane/diethyl ether. 65 mg (12% of theory) of the title compound were thus obtained.

Provenance & Evidence