Tris(propan-2-yl)silanethiol → Methyl-(2-triisopropylsilanylsulfanyl-benzyl)-carbamic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

(2-Iodo-benzyl)-methyl-carbamic acid tert-butyl ester (5.0 g, 14.4 mmol) in dry toluene (30 mL) was placed in two Emrys Optimizer EXP 20 mL tubes. To each tube tris(dibenzylideneacetone)dipalladium (66 mg, 0.072 mmol), bis(2-diphenylphosphinophenyl)ether (78 mg, 0.14 mmol), triisopropylsilanethiol (1.44 g, 7.56 mmol) and sodium tert-butoxide (900 mg, 9.36 mmol) were added sequentially. The tubes were sealed and subjected to microwave heating at 160° C. for 15 minutes. After cooling the mixture, the product was eluted through a plug of silica with ethyl acetate-heptane (1:10) to give 5.2 g (88%) of methyl-(2-triisopropylsilanylsulfanyl-benzyl)-carbamic acid tert-butyl ester. This product was dissolved in THF (70 mL) and cooled to 0° C. Tetrabutylammonium fluoride trihydrate (4.21 g, 13.3 mmol) dissolved in THF (40 mL) was added dropwise at 0° C. and the mixture was stirred at this temperature for 15 minutes. The crude mixture was poured onto a plug of silica gel and the product was eluted with ethyl acetate-heptane (1:2) to give 3.2 g (100%) of (2-mercapto-benzyl)-methyl-carbamic acid tert-butyl ester contaminated with traces of triisopropylsilane fluoride.

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