Reaktion #166146

Reaktionsgleichung

hexyllithium

hexyllithium

2′-iodo-2,4,6-triisopropylbiphenyl

Diethyl chlorophosphite

n-hexyllithium

diethyl chlorophosphite

hydrochloric acid

→

Ethyl 2′,4′,6′-triisopropylbiphenyl-2-ylphosphinate

Ausbeute 94.0%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 1-L 3-neck round-bottom flask was fitted with an addition funnel
2. 2
   Sonstigethe atmosphere was purged with nitrogen
3. 3
   SonstigeAnhydrous, degassed THF (170 mL)
4. 4
   workup.ADDITIONwas added to the 1-L flask
5. 5
   Temperaturmaintaining the temperature below −40° C
6. 6
   TemperaturThe solution was re-cooled to −60° C. (internal temperature)
7. 7
   Temperaturwhile maintaining the temperature below −40° C
8. 8
   workup.ADDITIONAfter addition
9. 9
   Temperaturwhile maintaining the temperature below −40° C
10. 10
    workup.WAITto proceed at −60° C. for an additional 30 min
11. 11
    SonstigeThe flask was removed from the cold bath
12. 12
    Temperaturto warm to 22° C
13. 13
    workup.ADDITIONThe resultant solution was diluted with heptane (340 mL)
14. 14
    Sonstigetransferred to a separatory funnel
15. 15
    SonstigeThe layers were separated
16. 16
    EinengenThe organic layer was concentrated under reduced pressure
17. 17
    Sonstigeto give an oil which
18. 18
    Sonstigewas used in the next reaction without further purification

Vorschrift

A 1-L 3-neck round-bottom flask was fitted with an addition funnel and the atmosphere was purged with nitrogen. Anhydrous, degassed THF (170 mL) was added to the 1-L flask and cooled to −60° C. (internal temperature). The addition funnel was charged with hexyllithium (2.38 M in hexanes, 57 mL, 135 mmol, 2.0 equiv). The hexyllithium was transferred into the cold THF over 20 min, maintaining the temperature below −40° C. The solution was re-cooled to −60° C. (internal temperature). A solution of 2′-iodo-2,4,6-triisopropylbiphenyl (27.5 g, 67.7 mmol, 1.0 equiv) in 170 mL of anhydrous, degassed THF was transferred, via cannula, drop wise to the n-hexyllithium solution. This was done over 25 min while maintaining the temperature below −40° C. After addition, the reaction mixture was allowed to stir at −60° C. for 30 min. Diethyl chlorophosphite (19.62 mL, 135 mmol, 2.0 equiv) was added to the reaction mixture, over 10 min while maintaining the temperature below −40° C. After addition of diethyl chlorophosphite, the reaction was allowed to proceed at −60° C. for an additional 30 min. Aqueous hydrochloric acid (1 M, 338 mL, 338 mmol) was added at −60° C. The flask was removed from the cold bath and the reaction was allowed to warm to 22° C. The resultant solution was diluted with heptane (340 mL) and transferred to a separatory funnel The layers were separated and the organic layer was assayed for product by quantitative HPLC (94% yield). The organic layer was concentrated under reduced pressure to give an oil which was used in the next reaction without further purification.

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