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A well-defined lithiated hydrazone derivative has been synthesized and fully characterized through various analytical platforms, including multinuclear (1H, 13C, 15N, 7Li) and two-dimensional NMR, high-resolution MS spectrometry, IR, and X-ray diffraction crystallography. It behaves as a binuclear species in the solid state and as a monomeric contact ion pair in solution. It has also been tested as a catalyst in hydrosilylation reactions, being the first lithium hydrazone reported to catalyze the full conversion of carbonyls of different nature into alcohols in short reaction times, at room temperature, and with catalyst loadings equal to or below 0.5 mol %. Kinetic studies have proven fractional order dependences with respect to ketone and silane and first order dependence in the case of the catalyst. The proposed reaction mechanism is characterized by the nucleophilic addition of the lithium hydrazonide to the silicon atom of the silane to give a five-coordinate silicon species.

A new iron complex based on a noninnocent anthraquinonic ligand has been synthesized and fully characterized through multiple techniques, including NMR, X-ray crystallography, mass spectrometry, and cyclic voltammetry. Exposure of ketone to that complex in the presence of (EtO)2MeSiH affords the corresponding silylated alcohol. Loadings as low as 0.25 mol % afford excellent yields at room temperature. Quantum–chemical analysis of the catalytic mechanism supports activation of the precatalyst to form a Fe–hydride intermediate, followed by ketone reduction and σ-bond metathesis.

2-Aminopyridines (H2NC5H3RN) react with [IrH2{(PPh2(o-C6H4CO))2H}] (1) in refluxing methanol to afford [IrH(PPh2(o-C6H4CO))(PPh2(o-C6H4CHNHC5H3RN))] (R = H (2), R = CH3 (3)) containing new terdentate PCN ligands in a facial disposition with the phosphorus atom trans to H and the new alkyl fragment trans to the other phosphorus atom. The formation of 2 and 3 requires imination of the hydroxycarbene moiety in 1, iridium to carbon hydrogen transfer, and coordination of the nitrogen atom of pyridine to iridium. In refluxing methanol the reaction of 1 with the N-substituted 2-(methylamino)pyridine leads to [IrH(PPh2(o-C6H4CO))(PPh2(o-C6H4C(OH)N(CH3)C5H4N))] (4), containing a PCN ligand with a hydroxyalkyl moiety trans to phosphorus and the nitrogen atom of pyridine trans to hydride. By performing this reaction in the presence of KOH, complex [IrH(PPh2(o-C6H4CO))(PPh2(o-C6H4C(OCH3)N(CH3)C5H4N))] (5), with a methoxyalkyl moiety in the PCN ligand and similar stereochemistry to that of 2 and 3, is obtained. In chl...

The reaction of [RhCl(COD)]2 (COD = 1,5-cyclooctadiene) with PPh2(o-C6H4CHO) (Rh/P = 1:1) in the presence of 4-methylpyridine (4-pic) or isoquinoline (iquin) leads to hydridoacyl complexes [RhHCl(PPh2(o-C6H4CO))L2] (L = 4-pic, 1; iquin, 2). Their reaction with diphenylphosphine oxide affords neutral complexes [RhHCl{(PPh2(o-C6H4CO))(PPh2O)H}L] (L = pyridine (py), 4; 4-pic, 5; iquin, 6) with trans P-ligands belonging to a formally PCP pincer ligand due to the formation of a O---H---O hydrogen bond between the oxygen atom of the diphenylphosphinous acid and the oxygen atom of the coordinated acyl. The reaction of 4 with chelating N-donors (LL) leads to displacement of pyridine and chloride to afford cationic [RhH{(PPh2(o-C6H4CO))(PPh2O)H}(LL)]BPh4 (LL = 2,2′-bipyridine, 7; biacetyldihydrazone, 8; biacetyloximehydrazone, 9; 2-aminomethylpyridine, 10), which undergo cleavage of the O---H---O hydrogen bond in solution. Complex 9, containing a nonsymmetric ligand, exists in solution as an equimolar mixture of t...

Triferrocenylsilane 2 was synthesized. Hydrosilylation reactions employing allyltriethoxysilane and diferrocenylmethylsilane (1) and triferrocenylsilane (2) yielded new ferrocenyltriethoxysilane co...