Abstract
Treatment of a variety of bis(alkynyl)metallocenes Cp 2M(–CC–R) 2 (M=Ti, Zr, Hf; R=CH 3, n-C 3H 7, n-C 4H 10, cyclo-C 6H 11) with tris(pentafluorophenyl)borane yields the metallocene(μ-RC 4R)borate betaines 3. These seem to be in an endothermic equilibrium with their methylenecyclopropene derived isomers—by means of an intramolecular alkyne insertion reaction—which are very effectively trapped by the reaction with tert-butylisocyanide to yield the complexes 6 that exhibit a methylenecyclopropene derived σ-ligand framework. The zirconocene compounds 6a (R=CH 3), 6c (R= n-C 3H 7), 6d (R= n-C 4H 9), and 6e (R=cyclo-C 6H 11) were characterized by X-ray crystal structure analyses. The hydrolysis of 6a, 6c and 6d gave the respective metal free systems 7 that exhibit a pronounced cyclopropenylium–borate–betaine character.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
