Réaction #58002

Équation de réaction

triflate

4,5-dimethyl-2-propionylphenyl trifluoromethanesulfonate

sodium carbonate

tert-butyl 4(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)carboxylate

→

84

tert-butyl 4-(4,5-dimethyl-2-propionylphenyl)-3,6-dihydropyridine-1(2H)-carboxylate

Solvants

ethanol toluene

Conditions de réaction

Traitement

1. 1
   Extractionextracted three times with EtOAc
2. 2
   LavageThe combined organic extracts were washed with brine
3. 3
   Séchagedried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Concentrationthe filtrate concentrated in vacuo
6. 6
   AutrePurification of the crude residue by flash chromatography on silica gel (gradient elution; 0%-25% EtOAc/hexanes as eluent)

Mode opératoire

A vigorously stirred solution of triflate 83 (10.5 g, 33.8 mmol), aqueous sodium carbonate (50.8 mL of a 2.0 M solution, 102 mmol), tert-butyl 4(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)carboxylate (10.45 g, 33.8 mmol), and tetrakis(triphenylphosphine)palladium(0) (3.91 g, 3.38 mmol) in ethanol/toluene (1:1, 100 mL) was degassed via three vacuum/nitrogen ingress cycles and heated to 75° C. for 30 min. The reaction mixture was poured into ice water and extracted three times with EtOAc. The combined organic extracts were washed with brine, dried (MgSO4), filtered, and the filtrate concentrated in vacuo. Purification of the crude residue by flash chromatography on silica gel (gradient elution; 0%-25% EtOAc/hexanes as eluent) afforded 84 as a colorless oil.

Source