Selective dehydrogenation of ammonia borane to polycondensated BN rings catalysed by ruthenium olefin complexes.

Dehydrogenation of ammonia borane to well-defined products is an important but challenging reaction. A dinuclear ruthenium complex with a Ru-Ru bond bearing a diazadiene (dad) unit and olefins as non-innocent ligands catalyzes the highly selective formation of conjugated polycondensed borazine oligomers (BNH), predominantly BNH, the BN analogue of superbenzene.

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.

No Transition Metals Required - Oxygen Promoted Synthesis of Imines from Primary Alcohols and Amines under Ambient Conditions.

The synthesis of imines denotes a cornerstone in organic chemistry. The use of alcohols as renewable substituents for carbonyl-functionality represents an attractive opportunity. Consequently, carbonyl moieties can be in situ generated from alcohols upon transition-metal catalysis under inert atmosphere.

Manganese and iron PCP pincer complexes - the influence of sterics on structure and reactivity.

The syntheses of various manganese and iron PCP pincer complexes a solvothermal oxidative addition methodology is described. Upon reacting [Mn(CO)] with the ligands (P(C-Br)P-iPr) (1a) and (P(C-Br)P-iPr) (1b), Mn(I) PCP pincer complexes [Mn(PCP-iPr)(CO)] (2a) and [Mn(-PCP-iPr)(CO)] (2b) were obtained. Protonation of 2a with HBF·EtO led to the formation of [Mn(κ,,-P(CH)P-iPr)(CO)]BF (3) featuring an η-C-H agostic bond.

Iron PCP Pincer Complexes in Three Oxidation States: Reversible Ligand Protonation To Afford an Fe(0) Complex with an Agostic C-H Arene Bond.

In the current investigation, the reaction of Fe(CO) with the ligand precursor 2-chloro-N,N-bis(diisopropylphosphanyl)-N,N-diethylbenzene-1,3-diamine (P(C-Cl)P- iPr) (1) was investigated. When a suspension of Fe(CO) and 1 in CHCN was transferred in a sealed microwave glass vial and stirred for 18 h at 110 °C the complex [Fe(PCP- iPr)(CO)Cl] (2) was obtained. In an attempt to prepare the hydride Fe(II) complex [Fe(PCP- iPr)(CO)H] (3), 2 was reacted with 1 equiv of Li[HBEt] in THF.

Chemoselective Hydrogenation of Aldehydes under Mild, Base-Free Conditions: Manganese Outperforms Rhenium.

Several hydride Mn(I) and Re(I) PNP pincer complexes were applied as catalysts for the homogeneous chemoselective hydrogenation of aldehydes. Among these, [Mn(PNP-Pr)(CO)(H)] was found to be one of the most efficient base metal catalysts for this process and represents a rare example which permits the selective hydrogenation of aldehydes in the presence of ketones and other reducible functionalities, such as C=C double bonds, esters, or nitriles. The reaction proceeds at room temperature under base-free conditions with catalyst loadings between 0.