Ein neuer Weg zu cyclopentadienyl-substituierten Diethylaminocarbin-Komplexen des Wolframs

We have developed a new, large scale, high yield synthesis of cyclopentadienyl-substituted tungsten diethylaminocarbyne complexes. Il the first step an almost quantitative conversion of (η 5 -C 5 H 5 )W(CO) 3 I and (η 5 -C 5 Me 5 )W(CO) 3 I using EtNC and Me 3 NO occurs to give an isomeric mixture of cis and trans (η 5 -C 5 H 5 )W(CO) 2 (EtNC)I and cis and trans (η 5 -C 5 Me 5 )W(CO) 2 (EtNC)I, respectively. Advantages of this route to low-and high-valent tugsten diethylaminocarbyne complexes are discussed in comparison to the classical Fischer procedure