Reaction #1509650

Reaction equation

2-(2-(2-bromo-5-(trimethylstannyl)thiophen-3-yl)ethyl)-4,5-dihydro-4,4-dimethyloxazol

triphenylphosphine

→

3-(2-(4,5-dihydro-4,4 dimethyl-2-oxazolyl)ethyl)thiophene

Solvents

DMF

Conditions

Workup

1. 1
   Otherthen purged with nitrogen for 15 min
2. 2
   OtherThe greenish-brown suspension solution was purged with nitrogen for 15 min
3. 3
   FiltrationThe reaction mixture was filtered thru celite
4. 4
   Extractionthe purple precipitate was extracted with chloroform
5. 5
   ExtractionThe chloroform extract
6. 6
   Concentrationwas concentrated
7. 7
   Extractionthe resulting solid was soxhlet-extracted with hexanes
8. 8
   Extractionthen extracted with chloroform
9. 9
   OtherThe solvent was removed
10. 10
    Otherto afford
11. 11
    Othera purple solid (2.1 g, 66% S5 yield)

Procedure

2-(2-(2-bromo-5-(trimethylstannyl)thiophen-3-yl)ethyl)-4,5-dihydro-4,4-dimethyloxazol (7.0 g, 15.5 mmol) was weighed in 100 mL Schlenk flask followed by the addition of 30 mL dry DMF then purged with nitrogen for 15 min. To this mixture, copper (II) oxide (1.24 g, 15.5 mmol, 1 eq.), triphenylphosphine (814 mg, 0.031 mmol, 0.20 eq.) and bis(dibenzylidene acetone)palladium(0) (446 mg, 0.776 mmol, 0.05 eq) was added all at once. The greenish-brown suspension solution was purged with nitrogen for 15 min then heated to 100° C. and stirred for 18 hrs under argon atmosphere. The reaction mixture was filtered thru celite and the purple precipitate was extracted with chloroform. The chloroform extract was concentrated and the resulting solid was soxhlet-extracted with hexanes then extracted with chloroform. The solvent was removed to afford a purple solid (2.1 g, 66% S5 yield). 1H NMR (300 MHz, CDCl3): δ=7.06 (s, 1H), 3.94 (s, 2H), 3.14 (d, 2H), 2.66 (d, 2H), 1.28 (s, 6H); 13C NMR (75 MHz, CDCl3): δ=166.7, 138.4, 134.4, 132.4, 129.8, 80.0, 68.0, 29.6, 29.2, 26.4. CDCl3

Source