From Box to Bench: Air-Stable Molybdenum Catalyst Tablets for Everyday Use in Olefin Metathesis

Abstract

Molybdenum- and tungsten-based olefin metathesis catalysts have demonstrated excellent results in the control of cis (Z-) selectivity as well as enantioselectivity. However, their air and moisture sensitivity, which requires the use of a glovebox, has prevented their more widespread use by organic chemists. Now we report on developed, preweighed Mo catalysts formulated in paraffin tablets. The significantly improved air stability, high homogeneity, and uniformity of the pellets allow researchers to carry out reactions on the bench avoiding the need of a glovebox. The two different Mo-based complexes which were packed into tablets are XiMoPac-Mo001 (1) that can be used to achieve endo-selective enyne ring-closing metathesis (RCM) reactions, inter alia; and XiMoPac-Mo003 (2) which was reported among the best catalysts to promote Z-selective cross-metathesis. For the evaluation of the wax-protected catalysts commonly used, highly reproducible robust model reactions were chosen: homo cross-metathesis (HCM) of...