A stable ruthenium complex bearing a 1,2-dicarbadodecaborane(12)-1,2-dithiolate ligand and its activation for olefin metathesis

In this article, a new ruthenium carbene catalyst containing a N-heterocyclic carbene, a pyridine-appended benzylidene carbene, and a 1,2-dicarbadodecab-orane(12)-1,2-dithiolate ligand was synthesized. The ruthenium complex is very stable in air or in solution owing to the large steric hindrance and strong coordination effect of the ligands. The ruthenium complex is almost inert for olefin metathesis reactions. When combined with a Lewis acid or a p-toluene sulfonic acid, the ruthenium complex could catalyze the cross metathesis reactions of terminal alkenes and (Z)-but-2-ene-1,4-diol to give high yields of desired products. The E-products were obtained predominantly in these reactions. Similar to other ruthenium-based catalysts, this new ruthenium complex can tolerate many different functional groups. (C) 2018 Elsevier B.V. All rights reserved.