Synthesis and Reaction Chemistry of Heterodi‐ and Heterotrimetallic Transition‐Metal Complexes Based on 1‐(Diphenylphosphanyl)‐1′‐terpyridylferrocene

The reaction of [Fe(η 5 -C 2 H 4 PPh 2 )(η 5 -C 5 H 4 terpy)] (5; terpy = 2,2':6',2"-terpyridin-4'-yl) with diverse transition-metal compounds including [PtCl 2 (Et 2 S) 2 ], [Pd(cod)X 2 ], [AuCl(tht)], [CuBr], [Mo(CO) 4 (nbd)], and [{RhCl(cod)} 2 ] (X = Cl, Br; tht = tetrahydrothiophene; nbd = norbornadiene; cod = cyclooctadiene) to afford heterobi- and trimetallic complexes and a coordination polymer is reported. The following compounds were prepared: [Fe(η 5 -C 2 H 4 PPh 2 (PtCl 2 (SEt 2 )})(η 5 -C 5 H 4 terpy)] (7), trans-[PtCl 2 {(Ph 2 P-η 5 -C 2 H 4 )(η 5 -C 5 H 4 terpy)-Fe} 2 ] (9), [Fe(η 5 -C 2 H 4 PPh 2 PdCl 2 )(η 5 -C 5 H 4 terpy)] (12), [Fe{η 5 -C 5 H 4 PPh 2 (Cl 3 Pd - )}(η 5 -C 5 H 4 terpy{(dmso) 2 ClNi + })] (14), trans-[PdX 2 {(Ph 2 P-η 5 -C 5 H 4 )(η 5 -C 5 H 4 terpy)Fe} 2 ] (16a, X = Cl; 16b, X = Br), [Mo(CO) 4 {(η 5 -C 5 H 4 PPh 2 )(η 5 -C 5 H 4 terpy)Fe} 2 ] (17), [Fe{η 5 -C 5 H 4 Ph 2 P(CuBr)}(η 5 -C 5 H 4 terpy)] n (19), [Fe(η 5 -C 5 H 4 Ph 2 P(AuCl)}(η 5 -C 5 H 4 terpy)] (22), [Fe(η 5 -C 5 H 4 Ph 2 P-(Rh(cod)Cl})(η 5 -C 5 H 4 terpy)] (23), [Ru({η 5 -C 5 H 4 Ph 2 P(AuCl)}-(η 5 -C 5 H 4 terpy)Fe) 2 ]Cl 2 (25), and [Fe{η 5 -C 5 H 4 PPh 2 -(PdCl 2 )}{η 5 -C 5 H 4 -CH=CHC(O)(py)}] (26). The molecular structures of 5, 9, 12, 14, 16b, 22, and 26 in the solid state are reported. They show typical features of related phosphanyl-ferrocenes and terpyridylferrocenes. Characteristic of 12 is a C-H activation as a result of the close distance of palladium to the terpyridyl moiety. Complexes 12, 26, and [PdCl 2 (dppf)] [dppf = 1,1'-bis(diphenylphosphanyl)ferrocene], for comparison, were used in preliminary studies as catalysts in the carbon-carbon coupling of iodobenzene with tert-butyl acrylate to give (E)-tert-butyl cinnamate. The conversion amounts to 80 % with a turnover number of 160 and turnover frequency of 48 h -1 .