4,4,5,5-Tetramethyl[1,3,2]dioxaborolane → 5-methoxy-1-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole

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Reaction Conditions

Reaction Steps

The 3-iodo-5-methoxy-1-methyl-1H-indole (9.90 g, 34.5 mmol) in 1,4-dioxane (200 mL) was treated with PdCl2(dppf)-CH2Cl2 (1.41 g, 1.72 mmol), TEA (33.6 mL, 241 mmol) and 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (28.7 g, 224 mmol). The mixture was heated to about 100° C. for about 40 min. The mixture was cooled to rt and concentrated under reduced pressure. The material was stirred with EtOAc (300 mL) at rt for about 30 min and then filtered. The filtrate was concentrated under reduced pressure and the residue was purified by silica gel chromatography eluting with 100% DCM to give 5-methoxy-1-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole (3.7 g, 37%): LC/MS (Table 2, Method a) Rt=2.68 min; MS m/z 288 (M+H)+.

Provenance & Evidence