Cp₂ZrCl₂-Mischmetall as a New ‘Cp₂Zr’ Equivalent

Significance

This work describes a simple and practical preparation of well-known ‘Cp₂Zr’ species, which have been applied to a large variety of useful synthetic transformations. Mischmetall is a cheap, easy-to-handle and selective reducing agent. The reactions proceed smoothly at ambient temperature. The mild nature of the reducing agent allowed performing of previously unknown reactions of terminal alkynes with zirconocenes. Also, novel intramolecular reactions of ene- and yne-imines became possible using this elegant method.