Tributyltin Chloride → Tert-butyl 2-tributylstannanylethynylpyrrolidine-1-carboxylate

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Reaction Conditions

Reaction Steps

n-Butyllithium (1.6M in hexanes, 12.3 mL) was added over 2 minutes to a stirred solution of tert-butyl 2-ethynylpyrrolidine-1-carboxylate (3.65 g) in anhydrous THF (80 mL) at −78° C. under nitrogen and then the mixture was allowed to warm to −30° C. over one hour. Tributyltin chloride (6.41 g) was then added dropwise at −30° C. and the mixture was allowed to warm to −10° C. and quenched by addition of saturated sodium bicarbonate solution. The layers were separated and the organic layer was dried (Na2SO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-5% to give tert-butyl 2-tributylstannanylethynylpyrrolidine-1-carboxylate (5.54 g) as a colourless oil.

Provenance & Evidence