Triisopropylsilyl trifluoromethanesulfonate → 9-Benzyl-3,6-bis(triisopropylsilyl)-9H-carbazole

Participants

Reaction Conditions

Reaction Steps

A 2 L dry round bottom flask was charged with N-benzyl-3,6-dibromocarbazole 3 (49 g, 0.118 mol) and 1 L of dry THF was added. The mixture was stirred until N-benzyl-3,6-dibromocarbazole 3 was dissolved. The mixture was then cooled to −78° C. and 2.5 M n-BuLi in hexanes (104 ml, 0.26 mol) was added dropwise. The mixture was stirred at −78° C. for 15 min and triisopropylsilyl-trifluoromethyl sulfonate (66 ml, 0.26 mol) was added. The mixture was left to warm up to room temperature overnight. The mixture was then quenched with sat. NH4Cl, extracted with methyl-t-butyl ether, dried over Na2SO4, filtered, concentrated, and purified over a 330 g SiO2 column to yield 9-benzyl-3,6-bis-triisopropylsilanyl-9H-carbazole 4 23.0 g (35%) as a transparent oil.

Provenance & Evidence