Lithium diisopropylamide → tert-butyl 3-methyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 462 mg 3-methyl-indole-1-carboxylic acid tert-butyl ester in 2.5 ml anhydrous tetrahydrofuran at −78° C. under argon is 1.2 ml of a 2M LDA (Li-diisopropylamine) solution in THF/hexane and stirred at 0° C. for 30 min to complete the deprotonation. The reaction mixture is cooled to −78° C., 0.6 ml 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane and stirred at 0° C. for 60 min. The reaction is quenched by the addition of 2 ml MeOH/water (1:1), diluted into water and extracted with ethylacetate. After evaporation of the solvent and purification on silica gel 385 mg of 3-methyl-2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-indole-1-carboxylic acid tert-butyl ester are obtained.

Provenance & Evidence