Di-tert-butylchlorophosphine → 6-((di-tert-Butylphosphino)methyl)-2,2'-bipyridine

Participants

Reaction Conditions

Reaction Steps

An oven-dried 500 mL three-necked round bottom flask equipped with an argon inlet, a stirring bar, dropping funnel and one rubber septum was cooled under a stream of argon. The flask was then charged with 6-methyl-2,2′-bipyridine (3.40 g, 20 mmol) in 80 mL dry ether. The solution was cooled to 0° C. and 13.4 mL of a 1.8 M solution of commercial lithium diisopropylamide (LDA) in heptane/THF/ethylbenzene (24 mmol) was added dropwise via syringe during 15 minutes. The resulting brown colored mixture was stirred for 1 hr at 0° C. and then cooled to −78° C. and a solution of di-tert-butylchlorophosphine (4.34 g, 24 mmol) in 30 mL dry ether was added dropwise (˜30 min) to it. The stirring was continued for a further 1 hr at −78° C. and the mixture was allowed to slowly warm up to room temperature and stirred overnight. To this reaction mixture was added 40 mL of degassed water and the ether phase was separated under N2 atmosphere. The aqueous phase was extracted with ether (2×50 mL). The combined ether solutions were dried over anhydrous Na2SO4, filtered under N2 pressure, and the solvent was removed under vacuum to get brownish-white solid. This was purified by column chromatography in the nitrogen glove box (basic alumina; hexane:ether (10:1) as eluent) to yield 4.46 g (71%) of 6-di-tert-butylphosphinomethyl-2,2′-bipyridine (BPy-tPNN) as a white solid.

Provenance & Evidence