Studies on the cyclometallation of ferrocenylimines

This review describes the cyclometallation reaction, including cyclomercura tion, cyclopalladation and cycloplatination of Schiff base type of ferrocen ylimines as well as the transmetallation reaction of cyclometallated ferroc enylimines and the stereochemistry associated with these reactions. The app lications of cyclopalladated ferrocenylimines in several fields are also de monstrated in this review. The molecular and crystal structures of the prod ucts as well as the absolute configurations of optically active products we re established by X-ray diffraction, NMR techniques, IR, UV-vis, etc. The g eneral features of these reactions, especially the regio selectivity and th e reaction mechanisms, are discussed. In addition, the structure -property relationships are discussed throughout this investigation. The transmetalla tion of optically pure cyclometallated ferrocenylimines with other metals s uch as mercury, tin and tellurium was found to proceed with complete retent ion of stereochemistry. This discovery led to a convenient method for the s ynthesis of optically pure cyclometallated organic compounds that are diffi cult to prepare by using conventional methods. Accordingly, a number of cyc lometallated ferrocenylimines have been prepared in optically pure forms, w hich display surprisingly high angles of rotation. (C) 2001 Elsevier Scienc e BN. All rights reserved.