Development of a new method for the in-situ formation of an active olefin metathesis catalyst

A straightforward one-step method was developed to generate a new olefin metathesis catalyst in-situ. The new method is based on two commercial materials (Ru(pcymene) Cb and tricyclohexylphosphine) and an easily prepared derivative of propargyl alcohol. The catalyst solution obtained by our method is free of inhibiting by-products and can therefore be used to promote olefin metathesis reactions without further treatment. Furthermore, the method requires only one equivalent of the expensive tricyclohexylphosphine ligand, while other methods to prepare similar catalysts (e.g., first-generation Grubbs and first-generation Hoveyda catalysts) involve two equivalents oftricyclohexylphosphine. The new catalyst possesses catalytic activity similar to that of the first-generation Hoveyda catalyst in RCM, CM, and ROMP and shows excellent stability in solution. This new method may well be the most convenient and least costly synthesis of a highly active olefin metathesis catalyst. This work is of great significance, considering that olefin metathesis is widely used in synthetic organic, medicinal, and polymer chemistry in academic and industrial research laboratories and in manufacturing