Kinetically controlled E -selective catalytic olefin metathesis

Abstract

EZ catalyst control in olefin metathesis A decade has passed since the partner-swapping chemical dance known as olefin metathesis garnered a Nobel Prize, and distinct routines continue to emerge. In general, olefins are most stable in an E configuration, with the two largest substituents diametrically opposed. However, chlorine and fluorine substituents often invert this trend, favoring the alternate Z geometry. Nguyen et al. report a molybdenum metathesis catalyst with ligands carefully optimized to produce Cl- and F-substituted E olefins more quickly than the more stable Z isomers. Science , this issue p. 569