Ein einfacher Syntheseweg fuer Cyclobutenylidenwolfram-Komplexe-Struktur von Pentacarbonyl(phenylacetylen)wolfram

Article abstract of DOI:10.1016/0022-328X(94)05256-B

A convenient method for the preparation of cyclobutenylidene complexes is presented.Photolysis of W(CO)6 in CH2Cl2 gives (CO)5W (2).Substitution of coordinated CH2Cl2 in 2 by terminal alkynes, HC<*>CR, gives thermolabile alkyne(pentacarbonyl)tungsten complexes (CO)5WCR> (3) a), ^tBu (b), c-Hex (c), COOMe (d), C(=CH2)Me (e), CH=C(OMe)H (f)>. <2 + 2>-Cycloaddition of the C<*>C bond of N,N-diethylaminoprop-1-yne to that of the coordinated terminal alkyne and subsequent tautomerization afford the cyclobutenylidene complexes (6).Analogously, the successive reactions of 2 with 1-ethynylcyclohexene and N,N-dimethylaminoprop-1-yne give (7).In addition to the compounds 6 and 7 the thermolabile complexes 3a and 3d could also be isolated.The structure of 3a has been established by an X-ray structure analysis.Keywords: Tungsten; Cyclobutenylidene complexes; Synthesis; X-ray structure; Alkyne complexes