The chemistry of cyclopentadienyl-ruthenium and -osmium complexes. 1. The preparation and substitution reactions of (.eta.4-cycloocta-1,5-diene)(.eta.5-cyclopentadienyl)haloruthenium(II) complexes. Versatile new synthetic precursors to open-face cyclopentadienylruthenium(II) chemistry

Abstract

Treatment of [(v4-CsHlz)RuH(NH2NMe2)3]PF6 (C8HlZ = cycloocta-1,5-diene) with cyclopentadienylthallium in refluxing acetone affords the novel cyclopentadienyl-ruthenium(I1) complex [ (q5-C5H5)Ru-(v4-CsHlz)H] (1). Reaction of 1 with halogenating agents (CC14, CH2Brz, CH31) in pentane gives the halo complexes [(v5-C5H5)Ru(v4-C8Hl2)X] (2-4; X = C1, Br, I), while halide metathesis on 2 using either NaBr or NaI in methanol provides alternative routes to 3 and 4, respectively. The substitution of the cycloocta-1,5-diene and/or chloro ligands in 2 in a range of solvents and under mild reaction conditions is a rapid and facile process. Mono-and bidentate ligands [CO, PPh3, PMe3, 1,2-bis(diphenylphosphino)ethane, P(OMe)3, PPhzH, MeNC, t-BuNC, 2,6-MezC6H3NC, CN(CH2)6NC, 3,4,7,8-Me4-1,lO-phenanthroline] and the dienes (buta-1,3-diene, 2,3-dimethylbuta-1,3-diene, 1-methyl-4-(methoxycarbonyl)buta-l,3-diene, bicyclo[2.2.l]hepta-2,5-diene) substitute the cycloocta-1,5-diene ligand in 2, in ethanol, acetone, or tetrahydrofuran solutions to give neutral products of the general type [ (v5-C5H5)RuL2C1]. Polyolefins (cyclohepta-173,5-triene, cycloocta-l,3,5-triene, cyclooctatetraene) and aromatics (benzene, hexamethylbenzene, indene, benzyl chloride, triphenylamine) react with 2 in refluxing ethanol solution to give, following anion exchange with NH4PF6, salts of the general formulation [ (v5-C5H5)RuL ]PF& Sodium tetraphenylborate C6H5BPh3)]. Cyclopentadienylsodium reacts with 2 in tetrahydrofuran at room temperature giving ruthenocene, while sodium hydrotris( 1-pyrazoly1)borate (NaHBpz3) with 2 in ethanol yields the unusual "metallocene" [ (v5-C5H5)Ru(HBpz3)]. These compounds are all obtained in high yield and have been characterized by a combination of elemental analysis and spectroscopic methods (IR and 'H and 13C NMR spectroscopy).reacts directly with 2 in refluxing ethanol to give the zwitterionic 7 1 -arene complex [(v5-C5H,)Ru(v6-

Ruthenium-based bioconjugates: Synthesis and X-ray structure of the mixed ligand sandwich compound RuCpiPr(p-(CO2H)C6H4Tp) and labelling of amino acids and the neuropeptide enkephalin

“…While CpRuCl(cod) (cod = 1,5-cyclooctadiene) is kinetically labile and is known to undergo reaction with Tp transfer agents giving CpRuTp species [11,12], the Tp analogue TpRuCl(cod) is known to be quite inert to ligand substitution [20,21]. As outlined in Scheme 1, compounds 3, 4 and 6 were obtained by modifying the parent syntheses of CpRuTp from species containing a [RuCp R ] synthon [22], while 5 was synthesized starting from {Cp * RuCl 4 } [23].…”

“…Modifying the literature preparation of CpRuCl(cod) [12], we synthesized Cp iPr RuCl(cod) (2) by substituting TlCp with NaCp iPr in comparable yield as a golden yellow solid. Reaction of 2 and Tp 0 Li gave Cp iPr Ru(p-BrC 6 H 4 Tp) (6).…”

“…1-Hydroxy-1H-benzotriazole (HOBt) and benzotriazol-1-yl-N-tetramethyl-uroniumtetrafluoroborate (TBTU) were purchased from Iris Biotech (Germany). The reagents p-BrC 6 H 4 BBr 2 , (p-BrC 6 H 4 )TpLi [8,9,36], [Ru(H)(cod)(NH 2 NMe 2 ) 3 ][PF 6 ] [37], CpRuCl(cod) [12] and {Cp * RuCl} 4 [38] were prepared by literature procedures. NMR spectra were recorded at ambient temperature on Bruker DPX 200, DPX 250 and DRX 600 spectrometers.…”

“…For example, the synthesis of mixed ligand ferrocene analogues like CpFeTp is reported to be complicated [11], whereas a rather rich chemistry is found for analogue ruthenium compounds [11][12][13]. Further it has to be noticed, that the readily available FeTp 2 is known for temperature dependent spin-crossover behaviour [14], and that this behaviour can be triggered by small changes to the substituent on the boron, as reported for example for Fe(p-IC 6 H 4 Tp) 2 [15].…”

Ruthenium-catalysed synthesis of o-phthalates by highly chemoselective intermolecular [2 + 2 + 2] cycloaddition of terminal alkynes and dimethyl acetylenedicarboxylate

“…CpRuCl(cod) [11], Cp * RuCl(cod) (Cp * : pentamethylcyclopentadienyl, cod: 1,5-cyclooctadiene) [12], RuCl 2 (PPh 3 ) 3 [13], RuHCl(CO)(PPh 3 ) 3 [14], Ru(cod)(cot) [15], Ru(cot) (dmfm) 2 [16], RhH(CO)(PPh 3 ) 3 [17] and Pd(dba) 2 [18] were synthesised as described in the literature. Other complexes and substrates were commercially available and were used without further purification.…”