A new one-pot arylacetylene synthesis: 4-RC6H4C-≡C(TMS) from 4- RC6H4CN and LiC(TMS)3(THF)2 via Li[N(TMS)C(C6H4R-4)C(TMS)2](THF) (TMS = SiMe3, R = H, F, Br, OMe or Bu(t))

Article abstract of DOI:10.1016/S0040-4039(98)00933-2

Treatment of LiC(TMS)₃(THF)₂ with the nitrile 4-RC₆H₄CN in Et₂O at ambient temperature yields the new lithium 1-aza-allyl Li[N(TMS)C(C₆H₄R- 4)C(TMS)₂](THF) which readily eliminates LiN(TMS)₂ upon heating in refluxing benzene yielding the acetylene 4-RC₆H₄C≡C(TMS) in quantitative (TMS = SiMe₃; R = H, Br, OMe or Bu(t)) or low (R = F) yield.