Ein Beitrag zum Mechanismus der Entstehung von Cyclobutadien-Metall-Komplexen aus 3.4-Dihalogencyclobutenen

Abstract

The reaction between diironenneacarbonyl and three with respect to the positions of the methyl groups isomeric £rarcs-3,4-dichloro-dimethyl-cyclobut-l-enes is studied. Two of these isomers yield the expected 1,2-dimethyl-cyclobutadiene-irontricarbonyl; from the reaction of the third isomer a new iron-organic compound is obtained, the structure of which is determined by spectroscopic and chemical methods.

(Cyclobutadiene)iron TricarbonylA Case of Theory before Experiment

“…However, A is still used.) Once it was known that (cyclobutadiene)iron tricarbonyl was stable and that it could be prepared by halogen elimination from vicinal dihalocyclobutenes with Fe 2 (CO) 9 , others used this procedure to prepare diverse alkyl-substituted cyclobutadiene−iron carbonyl complexes: 1,2-dimethyl-3,4-diethyl-, trimethylethyl-, 1-ethyl-2,3-dimethyl-, isopropyl-2,3-dimethyl-, 1,2-dimethyl-3,4-diisopropyl-, trimethylisopropyl-, 1,2-dimethyl-, tetramethyl-, trimethyl-, and 1,3-dimethylcyclobutadiene−iron tricarbonyl, as well as 23 and 24 6 Rowland Pettit (reproduced by permission of Prof. J.…”