Silylacetylenes synthesis

By contrast, the isomerization of silyl olefins and addition of silylacetylenes =C—H bond into imines catalyzed by iridium complexes appears to serve as a suitable route for the synthesis of silylfunctionahzed organic compounds. Hence, the acquisition of experimental data on catalysis by iridium complexes in silicon chemistry may be regarded as an initial stage in the quest for catalytic processes leading to the synthesis of other p-block (e.g. B, Ge, Sn, P)-carbon bond-containing compounds. 

An unexpected rearrangement was observed during studies directed towards the synthesis of bicyclic keto silanes by the thermal rearrangement of cycloalkanones bearing an co-silylacetylenic chain P to the carbonyl group. Thus, the bicyclic enol silyl ether 2 was formed in 60-65% yield when the ketone 1 was heated neat at 300°C for 2 hours. 

ShaCK, Jean TS, Wang DC (1990) Intramolecular Radical Cyclization of Silylacetylenic or Olefinic a-Iodo Ketones Application to the Total Synthesis of ( )-Modhephene. Tetrahedron Lett 31 3745... 

Kamijo S, Jin T, Yamamoto Y (2004) Four-component coupling reactions of silylacetylenes, allylcarbonates, and trimethylsilyl azide catalyzed by a Pd(0)-Cu(I) bimetallic catalyst. Fully substitued triazole synthesis from seemingly internal alkynes. Tetrahedron Lett 45 689-691... 

Scheme 24 depicts a synthesis of functionalized trisubstituted olefins from [(trimethylsilyl)acetyl] trimethylsilane " this intermediate and other related acylsilanes can be prepared from silylacetylenes via a hydroboration-oxidation sequence. A stereoselective synthesis of /8-nitro- (and subsequently /3-amino-) alcohols reported this year proceeds as shown in Scheme 25, although the same O-silylated nitroalcohol intermediates can be obtained by the addition of aldehydes R CHO to silyl nitronates R CH=N02SiR3. These latter com-... 

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 trimethyl silylacetylenes the reactions can also be carried out in an intramolecular sense, leading to 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. ... 

Synthesis of Silylacetylenes via Ene Reaction. (TMS)allene undergoes ene reactions with 4-phenyl-1,2,4-triazoline-3,5-dione and other reactive enophiles to give silylacetylenes. ... 

Cuprous iodide n-butyllithium Geospecific synthesis of enesilanes from silylacetylenes... 

Propargyltrimethylsilanes can be readily prepared from halomethyltrimethyl-silane and the 1-yne anion. They have been extensively used in organic synthesis of furanones and allenes, and like silylacetylenes, as terminator groups for biomimetic polyene cyclizations and the generation of steroids. ... 

Scheme 5 Rapid stereoselective synthesis of trisustituted alkenes from silylacetylenes...

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