Heterobimetallic Complexes with a Propynylidene C3‐Bridge: General Synthetic Routes to Bimetallic Ethynylcarbene Complexes

Abstract

AbstractSequential reaction of the dimethylamino(trimethylsilylethylnyl)carbene complexes [(CO)5M'C(NMe2)CCSiMe3] [M' = W (1a)] with KF/THFMeOH, nBuLi and transition metal halides, [XMLn], affords heterobimetallic propynyliden complexes of the type [(CO)5M'C(N‐Me2)CCMLn] [MLn = Ni(PPh3) Cp (4a, b). Ni(PMe2Ph)2‐ {Mes) (Mes=2,4,6‐C6H2Me3) (5a), Rh(CO)(PPh3)2 (6a), Fe(CO)2Cp (7a,b)]. In contrast, reaction of 1a with MeLi · LiBr and [IFe(CO)2Cp] yields the novel N‐metallated complex [(CO)5WC{N(ME)Fe(CO)2Cp}CCSiMe3] (8a). The complexes [(CO)5M'C(NMe2)CCMLnFe(CO)2Cp (7a, b), Ru(CO)2Cp (10a,b), Ru(CO)(PPh3)Cp (11a), Mn(CO)5 (12a), Re(CO)5 (13a)] are accessible by Pd‐catalyzed coupling of the C‐stannylated carbene complexes [(CO)5M'C‐(NMe2)CCSnBu3] (9a, b) with [XMLn]. The related monomethylaminocarbene complexes [(CO)5M'C(NHMe)C CSnBu3] (16a, b), obtained by stannylation of [(C))5M'C(NHMe)CCH] (15a, B) with Bu3SnNEt2, react with [IFe(CO)2Cp] to give the bimetallic complexes [(CO)5M'C(NHMe)CCFe(CO)2Cp] (17a, b). The complexes 4a, 5a, 7a and 10a were characterized by X‐ray structural analysis. The spectroscopic and structural data suggest that the two metal centers in 4–7, 10–13, and 17 interact only weakly.