1,2-Diphenylacetylene, addition lithium

Activation of organolithium compounds. n-Butyllithium and phenyllithium react very slowly with diphenylacetylene. However, the 1 1 complex of either lithium compound and TMEDA reacts with diphenylacetylene at room temperature. For example, the reaction of /-butyllithium under these conditions followed by carbonation gives cis-4,4-dimethyl-2,3-diphenyl-2-pentenoic acid (1) and a trace of 2-phenyl-3-f-butylindone (2). Thus addition takes place as well as metallation.1... 

Af,Af-diethylgeranyIamjne, a precursor to (—)-menthol is achieved via the hydroamination of this substrate with lithium catalysts on an industrial scale [98]. A single example of intermolecular alkyne hydroamination also exists. Thus, piperidene undergoes addition to diphenylacetylene in the presence of 10 mol% [Sr CH(SiMe3)2 2(THF)2] at 60 °C in CgDe solution over a period of 17 h a 10 1 mixture of syn- and antf-addition products are isolated consistent with an isomerization event occurring under the reaction conditions [98]. 

Polar metal-carbon bonds, such as are found in the organometallic compounds of the most electropositive elements, can add to olefins and acetylenes, especially when the latter bear electron-withdrawing substituents, which either increase the polarity of the C=C or C=C bond or can stabilize a negative charge in the transition state. Thus butyl-lithium adds to diphenylacetylene in diethyl ether, thought not in pentane, and trans-butylstilbene may be isolated after hydrolysis, showing that cis- addition occurs ... 

The first record of an intramolecular organometallic addition onto an arene deals with the lithium-mediated conversion of tolane (diphenylacetylene) into 1,2,3-triphenylnaphthalene (186, M = Obviously (Z,Z)-l,2,3,4-tetraphenyl-l,3-... 

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