Selective Transfer Semihydrogenation of Alkynes Catalyzed by an Iron PCP Pincer Alkyl Complex.

Two bench-stable Fe(II) alkyl complexes [Fe(κPCP-PCP-Pr)(CO)(R)] (R = CHCHCH, CH) were obtained by the treatment of [Fe(κPCP-PCP-Pr)(CO)(H)] with NaNH and subsequent addition of CHCHCHBr and CHI, respectively. The reaction proceeds via the anionic Fe(0) intermediate Na[Fe(κPCP-PCP-Pr)(CO)]. The catalytic performance of both alkyl complexes was investigated for the transfer hydrogenation of terminal and internal alkynes utilizing PhSiH and PrOH as a hydrogen source.

Solvothermal synthesis of cobalt PCP pincer complexes from [Co(CO)].

Unlabelled: Treatment of [Co(CO)] with the -substituted P(C-X)P ligands (X = Br, Cl; R = Pr, Bu) bearing Y = NH and CH linkers under solvothermal conditions affords the five-coordinate Co(I) and Co(III) complexes [Co(PCP-R)(CO)] and [Co(PCP-R)X]. The later are paramagnetic exhibiting a solution magnetic moment in the range of 3.0-3.

Base metal complexes featuring a new pyrazole-derived PCP pincer ligand.

A new pyrazole-derived PCP pincer ligand featuring a 1-methylpyrazole backbone tethered to two di(isopropyl)phosphine moieties phenylene spacers (P(CH)P-iPr) was prepared. When reacting the ligand with group six carbonyl complexes [M(CO)] (M = Cr, Mo, W) at 130 °C, complexes of the type [M(κ-PCP-iPr)(CO)] were obtained featuring a κ,-bound ligand with a pendant phosphine arm. Upon an increase of the reaction temperature to 150 °C, in the case of molybdenum, the formation of the complex [Mo(κ-PCP-iPr)(CO)] was observed featuring a weak Mo-C bond.