Functionalised alkenylcarbene metal complexes (M=Ru, W, Cr) by activation of propargyl alcohol derivatives

The reaction of arene ruthenium(II) complexes [Ru(η6-C6Me4R2)(PMe3)Cl2] (1, R=Me; 1′, R=H) with propargyl alcohol derivatives HCC(H)(OH)(p-C6H4X) (a, X=HCC(H)(OH); c, X=CHO; d, X=CHCH2; e, X=CHCHCHCH2) and methanol gives the (methoxy)-alkenylcarbene ruthenium complexes [Ru(η6-C6Me4R2)(PMe3)(Cl) (C(OMe)(CHCH-p-C6H4X)][PF6] (2a) and (2′c–e). Similarly, the half-sandwich carbene complexes [Ru(η5-C5H5)(CO)(PPh3)(C(OMe)(CHCH-p-C6H4X)][BF4] (4a and 4d) are obtained from [Ru(η5-C5H5)(CO)(PPh3)(Cl)] (3) and propargyl alcohol derivatives a and d, respectively. Treatment of M(CO)5(THF) (M=W, Cr) with a and HCC(H)(OH)C4H2S(OH)(H)CCH (b) yields the monometallic complexes (CO)5MC(OMe)(C(OMe)(CHCHAr(OH)(H)CCH)] (5a) (M=W; Ar=C6H4), 5b (M=W; Ar=C4H2S), and 7a (M=Cr; Ar=C6H4) as the major products, and the bimetallic complexes (CO)5WC(OMe)CHCHArCHCH(OMe)CW(CO)5 (6a) and (6b) as the minor products. Finally, the reaction of 5a and 5b with amines (iPrNH2, Me2NH, Et2NH), and diamines such as ethylene diamine and piperazine produces the expected amino alkenyl–tungsten complexes 9a–13a and 9b in high yields.