Réaction #219282

Équation de réaction

3-methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester

n-butyllithium

dicyclohexylamine

tri-tert-butylphosphonium tetrafluoroborate

1-bromo-3-tert-butyl-benzene

→

1-(3-tert-butyl-phenyl)-3-methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester

Rendement 81.0%

Solvants

toluene

ethyl acetate

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGAfter stirring for 30 min
2. 2
   AutreThe solution was placed into a preheated oil bath at 60° C
3. 3
   workup.STIRRINGAfter stirring for 16 h
4. 4
   Autrechromatographed with 99:1, 49:1, 24:1, and 23:2 hexanes

Mode opératoire

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.

Source