Acetylene ethylidene compounds

With a,j -acetylenic nitriles, acetylenic organomagnesium compounds produce only the ketones resulting from 1,2-addition [4], Recently, the 1,4-addition of RMgX (R = saturated, vinylic, or allylic groups) and other organometallics to the conjugated structure of a-ethylidene-(Z)-1//-indole-2-acetonitrile has been observed [38] ... 

Problem 8.38 Show reagents and reactions needed to prepare the following compounds from the indicated starting compounds, (a) Acetylene to ethylidene iodide (1.1-diiodoethane). b) Propyne to isopropyl bromide,... 

Problem 8.33 Show reagents and reactions needed to prepare the following compounds from the indicated starting compounds, (a) Acetylene to ethylidene iodide (1,1-diiodoethane). (b) Propyne to isopropyl bromide, (c) 2-Butyne to racemic 2,3-dibromobutane. (d) 2-Bromobutane to trans-2-butene. (e) n-Propyl bromide to 2-hexyne. (/) 1 -Pentene to 2-pentyne. ... 

One example of C-vinylation of an aromatic compound is the reaction of /7-tert-butyl-phenol and acetylene [47] to give ethylidene-bridged oligomers (eq. (21)), which are formed by dual attack of the aromatic compound on acetylene. The catalyst employed is zinc naphthenate. These products are used, inter alia, as vulcanizing auxiliaries in the tire industry. 

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