Dicyclohexylamine → 1-(3-Tert-butyl-phenyl)-3-methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester

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Reaction Steps

A 1.6 M solution of n-butyllithium (12.0 mL, 19.2 mmol) was added to a solution of dicyclohexylamine (3.7 mL, 18.6 mmol) in toluene (40 mL). After stirring for 5 min, 3-methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester (3.45 g, 14.4 mmol) was added. After stirring for 30 min, 1-bromo-3-tert-butyl-benzene (3.16 g, 14.8 mmol) was added followed by the simultaneous addition of tri-tert-butylphosphonium tetrafluoroborate (220 mg, 758 mmol) and tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (380 mg, 367 mmol). The solution was placed into a preheated oil bath at 60° C. After stirring for 16 h, the solution was directly flash chromatographed with 99:1, 49:1, 24:1, and 23:2 hexanes:ethyl acetate as the eluant to yield 4.31 g (81% yield) of 1-(3-tert-butyl-phenyl)-3-methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester as a light yellow oil.

Provenance & Evidence