Lithium-phenylethynyl complexes

Finally some homoleptic alkyne complexes of scandium and some rare earths are known. Tris(phenylethynyl) scandium is formed as a dark brown product after treatment of phenylethyne with butyl lithium at — 78°C in hexane, followed by the addition of scandium trichloride at room temperature. The compound is inflammable in air (Hart and Saran, 1968 Hart et al., 1970). The reaction of the anionic... 

Alkoxy-substituted Tj -cyclohexadienyliumiron complexes are less frequently applied to nucleophilic substitution. Reaction of the T -l-ethoxycyclohexadienyliumiron complex salt with lithium phenylacetylide leads to ipso substitution. Treatment of the resulting (r] -cyclohexadiene)iron complex with acid affords the 1-phenylethynyl-substi-tuted Tj -cyclohexadienyliumiron complex salt by elimination of ethanol (Scheme 4-174). 

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