Trimerisierung von Propiolsäuremethylester an Dicarbonylbis(phosphordonor)eisen-Komplexen

Abstract

The dinitrogen complex (CO) 2L 2FeNNFeL 2(CO) 2 (L  P(OMe) 3 ( 1a), P(OMe) 3 ( 1a), P(O iPr) 3 ( 1b), PEt 3 ( 1c)) reacts with methyl propiolate under elimination of N 2 to yield the corresponding acetylene substitution products [(CO) 2L 2Fe(η 2-HCCCOOMe)] ( 2) and the prototropic vinylidine complexes [(CO) 2 L 2FeCC(H)COOMe)] ( 3). In a subsequent reaction 2,3 inserts two equivalents of methyl propiolate and results in the formation of carbonyl-2,4,6-tris(methoxycarbonyl)hexa-1,3,5-triene-1,5-diyl-bis(phosphorus-donor)iron compounds ( 4,5a) and a carbonyl-1,3,6-tris(methoxycarbonyl)fulvenebis(triisopropylphosphite)iron complex ( 6). The complexes 5a,6 were determined by X-ray diffraction analyses.