METALLOCYCLE SYNTHESIS ACCELERATED BY HIGH-PRESSURE

Reaction of cis-[FeH2(dmpe)(2)] (1) with diphenylbutadiyne results in an insertion into both of the iron-hydride bonds to form an iron metal locycle. Spectroscopic and crystallographic data of [Fe(PhHCC2CHPh)(dm pe)(2)] (3) show 1,4-diphenylbutatriene is symmetrically bound to the metal via the central double bond. The reaction to form the metallocyc lic complex is greatly accelerated by application of external pressure . A 41% yield of (3) is isolated after two days at atmospheric pressur e or after approximately 75 min at 800 MPa. (C) 1997 Elsevier Science S.A.