Lithium Bromide → 1-Acetyl-6'-benzyl-1',2'-dihydrospiro[azetidine-3,3'-indole]-1'-yl-carboxylic acid tert-butyl ester

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Reaction Steps

(1,3-Diisopropylimidazol-2-ylidene)(3-chloropyridyl)palladium (II) dichloride (2 mg, 10 mol %) and LiBr (41 mg, 0.47 mmol) were dissolved in dry NMP and the solution was degassed with N2 for 5 minutes. Then 1-acetyl-6′-chloro-1′,2′-dihydrospiro[azetidine-3,3′-indole]-1′-yl-carboxylic acid tert-butyl ester (100 mg, 0.29 mmol) and benzylzinc bromide (0.5M solution in toluene, 950 μL, 0.475 mmol) were added. The reaction mixture was stirred under N2 for 4 h. A second aliquot of catalyst (2 mg) and benzylzinc bromide (950 μL) were added and stirring maintained for 4 h. The reaction was quenched with water and extracted with EtOAc. The organic phase was dried (MgSO4), filtered and concentrated. The crude material was purified by column chromatography (EtOAc:petrol 1:1 to EtOAc 100%) to give the title compound (200 mg) as a pale yellow oil (ca. 50% pure by NMR, contaminated with NMP), used without further purification. MS: [M+H]+=393.

Provenance & Evidence