Cationic palladium(II) complexes have been found to be highly reactive towards aromatic C-H activation of arylureas at room temperature. A commercially available catalyst [Pd(MeCN)4](BF4)2 or a nitrile-free cationic palladium(II) complex generated in situ from the reaction of Pd(OAc)2 and HBF4, effectively catalyzes C-H activation/cross-coupling reactions between aryl iodides, arylboronic acids...

A series of structural models of the Ni centre in [NiFeSe] hydrogenases has been developed which exhibits key structural features of the Ni site in the H2 cycling enzyme. Specifically, two complexes with a hydrogenase-analogous four-coordinate 'NiS3Se' primary coordination sphere and complexes with a 'NiS2Se2' and a 'NiS4' core are reported. The reactivity of the complexes towards oxygen and pr...

Two ruthenium acetylide complexes [Ru]CtC(C5H3RN) (1a, R ) H; 1b, R ) Me; [Ru] ) Cp(PPh3)2Ru) containing 2-pyridyl groups are prepared and their chemical reactivities are explored. Protonation of the ruthenium acetylide complex 1a with HBF4 takes place at both the nitrogen atom and C , giving the dicationic pyridiniumvinylidene complex {[Ru]dCdC(H)(C5H4NH)}(BF4)2 (3a). Addition of BF3 to 1a yie...

Reaction of the complex [CpRe(NO)(CO)2]BF4 with triisopropylphosphine gives the chiral CO substitution product [CpRe(NO){P(/-Pr)3}(CO)]BF4. The corresponding triphenylphosphite complex [CpRe(NO){P(OPh)3}(CO)]BF4 may be obtained by oxidative CO removal. Reduction of the remaining CO ligand with NaBH4 furnishes the corresponding methyl com­ plexes [CpRe(NO)(L)(CH3)]. The structure of [CpRe(NO){P(...

The pentacoordinate [PtH{P(OEt)3}4]BF4 (1) hydride complex was prepared by allowing the tetrakis(phosphite) Pt{P(OEt)3}4 to react with HBF4.Et2O at -80 degrees C. Depending on the nature of the acid used, however, the protonation of the related Pt{PPh(OEt)2}4 complex yielded the pentacoordinate [PtH{PPh(OEt)2}4]BF4 (3) or the tetracoordinate [PtH{PPh(OEt)2}3]Y (4) [Y = BF4- (a), CF3SO3- (b), Cl...

The title compounds are accessed by sequences starting with racemic and enantiomerically pure [(eta5-C5H5)Re(NO)(PPh3)(CH3)]. Reactions with chlorobenzene/HBF4, PPh2H, and tBuOK give the phosphido complex [(eta5-C5H5)Re(NO)(PPh3)(PPh2)] (3). Reactions with Ph3C+ BF4-, PPh2H, and tBuOK give the methylene homologue [(eta5-C5H5)Re(NO)(PPh3)(CH2PPh2)] (9). Treatment of 3 or 9 with nBuLi or tBuLi an...

The one-step synthesis (33 % isolated yield) of a novel bicyclic diphosphane, [P(CH2)2NC6H4(4-NMe2)]2, P−P(NMe2), from the reaction [P(CH2OH)4]Cl and H2NC6H4(4-NMe2) in methanol is described. Surprisingly, P−P(NMe2) displays excellent air/solution stability (towards H2O, CH3OH) can also function efficiently as bridging ligand. Hence with [Pd(μ−Cl)(η3-allyl)]2 (η3-allyl=C3H5, C4H7) or [Pd(μ−Cl)(...

Selective functionalization reactions of aromatic and heteroaromatic halides with carbon, oxygen, and nitrogen nucleophiles have attracted much attention in the last decades. In addition to typical metal-catalyzed coupling reactions, direct functionalization of aryl halides through the formation of Grignard reagents offer new ways for the efficient construction of biologically interesting carbo...