Trimethyl-silylacetylene

Mayor et al. [13g] prepared the iodide 2 via substitution of the fluoride 18 by using sodium fcrt-butylthiolate (Scheme 10.5). A cross-coupling reaction with trimethyl silylacetylene generated the alkyne 19 that was desilylated by tetrabutylam-monium fluoride finally to provide 5. 

In a cross-coupling reaction of 3- or 4-chloropyridazines and trimethyl-silylacetylene in the presence of Pd(PPh3)2Cl2-CuI as catalyst, the tri-methylsilyl derivatives were obtained (82S312). The same transformation with monosubstituted acetylenes afforded 3-alkynylpyridazines or their... 

Trimethylsilyl-3-rnethylthio-l-propyne, 54 - (32) Trimethyl-silylacetylene, 55 - (32) Bis(trimethylsilyl)acetylene, 56 - (33) 1--Ethoxy-2-trimethylsilylacetylene, 57 - (34) 3-Trimethylsilyl-2 -propyn--l-ol, 58 - (35) 2-Butynoic acid, 59 - (3S) Methyl-1-propynyl sulfoxide,... 

Further work from Vollhardt s group on cobalt-catalysed cycloadditions of olefins and acetylenes has led to a synthesis of cyclohexadiene derivatives (188 n = 0—2) by addition of tricyclic compounds. The novel tricyclic compound (189) has been obtained from naphthoquinone by a [2 + 2]addition of l,l-bis(silylmethyl)ethylene followed by treatment with a Lewis acid. A key step in the first total synthesis of a decipiene diterpene is the formation of tricyclic ketone (190) by an intramolecular aldol condensation, which required the use of methanolic barium oxide. ... 

In a Schlenk. flask, a solution of 1.03 g (2.70 mmol) terpyridinetriflate in 30-mL abs. tetrahydrofuran under argon atmosphere, 0.758 mL (0.531 g, 5.40 mmol) trimethyl-silylacetylene, 57.0 mg (81.0 mmol, 3 mol%) bis(triphenylphosphine)palladium(II) chloride, 51.0 mg (0.270 mmol, 10 mol%) copper(I) iodide, and 13.4 mL of diisopropylamine was added. The black mixture was stirred for 2.5 h at ambient temperature. Subsequently, 125 mg of activated charcoal was added, stirred for 15 min, and filtered then, the solvent was removed under reduced pressure. The black crude product was purified by column chromatography (flash silica gel, 4.5 x 25 cm, CH2Cl2/MeOH 19 1). This gave 0.874 g (2.65 mmol, 98%) of the alkyne as a red-brown solid mp 163 °C 0.05 (CH2Cl2/MeOH 19 1). ... 

N-methylmethoxyamine (Scheme 23). The method appears to be the only one which allows direct conversion of an organolithium reagent into a secondary amine, usually isolated as the benzamide. 5-Amino-2-cyano-4-silylpyrroles can be prepared by the palladium or nickel catalysed condensation of silylacetylenes with trimethyl silyl cyanide (Scheme 24).60... 

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