Reaction #2161245

Reaction equation

1,1′-(azo dicarbonyl)dipiperidine

diisopropylamine

BuLi

hexane

Bu3SnCH(OH)Ph

→

Bu3SnC(O)Ph

Yield 36.2%

Solvents

THF

THF

Conditions

Workup

1. 1
   workup.ADDITIONIn a nitrogen-filled glove box, a 250 mL three-neck round bottom flask
2. 2
   Temperatureto warm to room temperature
3. 3
   Othera nitrogen inlet, and a glass stopper were attached to the round bottom flask
4. 4
   OtherThe apparatus was removed from the glove box
5. 5
   workup.ADDITIONfilled Schlenk line
6. 6
   TemperatureThe reaction mixture was cooled to about −78° C.
7. 7
   workup.ADDITIONthe Bu3SnCH(OH)Ph/THF solution was added dropwise
8. 8
   workup.ADDITIONAfter the addition
9. 9
   OtherThe glass stopper was then removed
10. 10
    OtherThe resulting reaction mixture
11. 11
    workup.STIRRINGto stir for 20-30 min at −78° C., during which time the reaction mixture
12. 12
    Temperatureto warm to about 0° C.
13. 13
    workup.STIRRINGstirred for approximately 30 min at that temperature
14. 14
    OtherThe reaction was quenched at 0° C. by the addition of approximately 14 mL saturated ammonium chloride
15. 15
    Othersolids formed in the reaction mixture
16. 16
    workup.ADDITIONfilled glove-box
17. 17
    Filtrationfiltered
18. 18
    Dryingdried (MgSO4)
19. 19
    Concentrationconcentrated
20. 20
    Otherto afford an orange oil

Procedure

This example demonstrates the synthesis and purification of the acylstannane complex Bu3SnC(O)Ph. In a nitrogen-filled glove box, a 250 mL three-neck round bottom flask was charged with diisopropylamine (1.31 g, 13.0 mmol) and 40 mL dry THF. The solution was cooled to about −30° C. and 2.5 M BuLi in hexane (5.2 mL, 13.0 mmol) was added slowly by syringe. The reaction mixture was allowed to warm to room temperature. A dropping funnel containing Bu3SnCH(OH)Ph (5.00 g, 12.6 mmol) dissolved in 20 mL dry THF, a nitrogen inlet, and a glass stopper were attached to the round bottom flask. The apparatus was removed from the glove box. The reaction setup was connected to a nitrogen-filled Schlenk line. The reaction mixture was cooled to about −78° C., and the Bu3SnCH(OH)Ph/THF solution was added dropwise. After the addition, the reaction mixture was allowed to stir for 15-20 min at −78° C., during which time the color changed from yellow to light orange. The glass stopper was then removed, and 1,1′-(azo dicarbonyl)dipiperidine (3.18 g, 12.6 mmol) was quickly added as a solid. The resulting reaction mixture was allowed to stir for 20-30 min at −78° C., during which time the reaction mixture turned dark orange. The reaction mixture was allowed to warm to about 0° C., and stirred for approximately 30 min at that temperature. The reaction was quenched at 0° C. by the addition of approximately 14 mL saturated ammonium chloride; solids formed in the reaction mixture. The reaction mixture was brought into a nitrogen-filled glove-box, filtered, dried (MgSO4), and concentrated to afford an orange oil. Chromatography on silica gel using 95/5 hexane/ethyl acetate as the eluent afforded 1.80 g of Bu3SnC(O)Ph as a yellow-orange oil. 1H NMR(C6D6) δ7.9 (2H, d, Hortho), 7.3 (3H, mult, Hmeta & Hpara), 1.8-0.9 (27H, Bu's); 119Sn NMR (CDCl3) δ 87.4 relative to SnMe4; 13C NMR (CDCl3) δ244.8 (CO), 142.9, 132.8, 128.8, 127.7 (Caromatic), 29.1, 27.3, 13.6, 11.5 (Cbutyl).

Source