Synthesis and catalysis of a Z-stereoretentive ruthenium carbene catalyst chelated by 2,4,5,7-tetrachloro-1,8-dimercaptonaphthalene for olefin metathesis†
Abstract
In this work, a 2,4,5,7-tetrachloro-1,8-dimercaptonaphthalene ligand-chelated ruthenium-based carbene olefin metathesis catalyst was synthesized. The synthesized catalyst catalyzed the ring-opening cross-metathesis reactions of norbornene/exo,exo-5-norbornene-2,3-dimethanol with styrene/4-fluorostyrene to obtain high Z-products (97 : 3–99 : 1 Z/E). The cross-metathesis reactions of (Z)-2-butene-1,4-diol with terminal alkenes using the synthesized catalyst gave high Z-stereoretentive products (91 : 9–98 : 2 Z/E). Compared to the previously reported Ru catalysts with naphthalene-1,8-dithiolate and 1,2-dicarbadodecaborane (12)-1,2-dithiolate, the prepared Ru complex exhibited higher catalytic activity under similar catalytic conditions. In addition, the new catalyst tolerates various olefin substrates containing different functional groups.