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

HRID 1786670Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:10]([CH3:17])=[CH:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Li+].CC([N-]C(C)C)C.C(O[B:30]1[O:34][C:33]([CH3:36])([CH3:35])[C:32]([CH3:38])([CH3:37])[O:31]1)(C)C>O1CCCC1.C1COCC1.CCCCCC>[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:10]([CH3:17])=[C:9]1[B:30]1[O:34][C:33]([CH3:36])([CH3:35])[C:32]([CH3:38])([CH3:37])[O:31]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: 0 °C

Procedure

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 added 1.2 ml of a 2M LDA 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 are added, 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-carb-oxylic acid tert-butyl ester are obtained.

Workup

temperatureThe reaction mixture is cooled to −78° C.
stirringstirred at 0° C. for 60 min
customThe reaction is quenched by the addition of 2 ml MeOH/water (1:1)
additiondiluted into water
extractionextracted with ethylacetate
customAfter 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-carb-oxylic acid tert-butyl ester
customare obtained

Sources & evidence

ORD record: ord-47393936c874421891c1b4b0bc535d00
Source dataset: uspto-grants-2009_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07507734B2

Reaction notes

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