Heterosubstituted acetylene

The direction of primary intermolecular nucleophilic attack at heterosubstituted acetylenes of type HC —X, where X = R2N, RO, RS, is governed by the nature of heteroatom and can be different. 

Allylmetallation of y-heterosubstituted acetylenic lithium derivatives and reaction with different electrophiles preparation of (Z)-2-allyl-3-(terf-butoxy)-1 -chloro-1 -iodohex-1 -ene... 

Ynamines from other Heterosubstituted Acetylenes via Nucleophilic... 

More specifically, propargylic substrates may rearrange upon treatment with bases to give the corresponding heterosubstituted acetylenes via allene intermediates (61). 

The direction of the long-wavelength maximum shift caused by the heterosubstitution or the introduction of substituents is deterrnined by the Forster-Dewar-Knott rule (40—42). Spatial hindrances within the symmetrical PMDs cause bathochromic effects (39,43), whereas the introduction of an acetylenic bond is accompanied by the maximum shift to the short-wavelength spectral region (44). 

Selective heterosubstitution of phenylacetylene at the acetylenic carbon or at ortho position was achieved through different organometallic intermediates (Scheme 10.3). 

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