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Tantalum complexes acetylene

An intermolecular cyclotrimerization of an acetylenic nitrile was reported to proceed via the same alkyne-tantalum complex. The resultant pyridine derivative was obtained in 73% yield (Scheme 56).210... [Pg.430]

Acetylenes 191 (R1 = C5H11, Me3Si or MeS R2 = C5H11 or C10H21) react with tantalum ) chloride and zinc to form tantalum complexes. Addition of the imine... [Pg.570]

In 1982, Cotton et al prepared the first phosphinocarbene tantalum complex 99 from the reaction of Ta2Cl6(SMe2)3 with bis(diphenylphosphi-no)acetylene. The most remarkable feature of this reaction is the formal dimerization of the alkyne moiety.91... [Pg.210]

Acetylenes yield acrylanilides by insertion of aryl isocyanate into an intermediate tantalum complex, as shown in reaction 9. ... [Pg.199]

A number of metal complexes catalyses specific alkyne polymerizations, giving rise to four-, six- or eight-membered carbocyclic rings. The first work in this area was the nickel-catalysed formation of cyclooctatetraene (40) from acetylene by the group of Reppe ", but since then formation of cyclic systems from acetylenes has been found to be also catalysed by molybdenum, cobalt, iridium and tantalum. ... [Pg.498]

See other pages where Tantalum complexes acetylene is mentioned: [Pg.172]    [Pg.172]    [Pg.354]    [Pg.438]    [Pg.21]    [Pg.88]    [Pg.311]    [Pg.43]    [Pg.120]    [Pg.215]    [Pg.184]    [Pg.316]    [Pg.30]   
See also in sourсe #XX -- [ Pg.399 , Pg.402 ]



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