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Selective and quantitative reductive elimination (RE) of C[H.sub.3]I or C[H.sub.3]CN is seen at ambient temperature from the complex [(PNP)Rh(CN)(C[H.sub.3])] upon reaction in aprotic or protic solvents. The reductively eliminated C[H.sub.3]I have undergone selective electrophilic attack on the cyano ligand of the Rh complex in an aprotic solvent to give the corresponding alkyl isonitrole complex.

Pincer-type PSiP silanol Pt(II) complexes were prepared to generate a silanone intramolecularly bound to platinum. The intramolecular binding to transition metals in pincer-type complexes provide new pathways for the construction of more stable silanones and related transients by using additional protection against nucleophilic attack.

Paramagnetic monomeric Rh(II) PNP-type complexes were synthesized by oxidation of Rh(I) complexes with silver salts. The structure and reactivity was studied using x-ray diffraction, EPR, cyclic voltammetry and dipole moment measurement.

The importance of [Gd.sup.3+] complexes as the potential spin labels for high field (HF) pulsed EPR measurements is demonstrated. The complexes are found to be perfect for the job because of their high sensitivity and magnetic field values.

Generation, stabilization, and characterization of a methylene arenium cation, an extreme resonance form of a benzyl cation, are presented. It is found to exhibit reactivity patterns resulting, from the positively charged ring, such as facile ether C-O bond hydrolysis to the corresponding alcohol, and deprotonation to form a p-quinone methide complex.

A number of unusual reactions in which the PNP ligand takes an active role in the activation of [H.sub.2] and benzene, via facile aromatization/dearomatization processes of the ligand are reported. Results reveal that the new, dearomatized electron-rich PNP-based IR(I) complex 2 activates benzene to form an Ir(I)-Ph complex, which upon treatment with CO undergoes an oxidation process to form the Ir(III) complex involving proton migration from the arm to the metal with consistent dearomatization.

The reductive elimination of methyl iodide from a methyl Rh(III) pincer complex at room temperature is reported. It is shown that steric effects can have a major impact on the overall reductive elimination process, and might override electronic effects.

The selective [sp.sup.3] C-H activation of alkyl ketones at the B position by Ir(1) is reported. Calculations reveal that the selectivity is both kinetically and thermodynamically controlled, the latter as a result of carbonyl oxygen coordination in the product and that water has a strong influence on the regioselectivity.

The synthesis of aryl radical anion sigma-bound to a transition metal is reported. The electron is proven to be localized in the naphthyl unit, but reactivity is entirely different from that of the naphthide radical anion, as exemplified by water reduction to dihydrogen, rather than the expected ring protonation.

The design of novel ruthenium complexes, which efficiently and selectively catalyze dehydrogentation of primary alcohols to esters and H2 in high turnover numbers under relatively mild, neutral conditions, is reported. It is found to be an outstanding catalyst for the acceptorless dehydrogenation of primary alcohols to esters under mild, neutral conditions.

The first example of a phenoxonium cation stabilized by an unprecedented n (super 2) metal coordination to the quinonoid C=O double bond is presented. Phenoxonium cations are key intermediates in the oxidation of phenols and in biological oxidative coupling reactions.

An experimental and computational study of carbene complex formation from phenyl diazomethane in PCN and PCP-Rh system is reported. The results show that end -on Nu1-N complex formation proceeds the formation of the carbene complex in both the cases. Coordination of PhCHN2 to the metal centers in PCP and PCN system was found to be reversible both experimentally and computationally.

Research has been conducted on mono- and bimetallic complexes. The authors describe the synthesis of the ligand system for these complexes based on a calixarene.

The authors review the publications on cyclometalated phosphine-based pincer complexes. The topics of interest include the developments in transition metal chemistry with PCP ligands and derivatives, the mechanistic aspects of catalysis, ligand activation and coordination of different organic substrates, and bond activation.

We report here the activation of CO2 using two Mn-PNN pincer complexes that can exhibit different modes of metal–ligand cooperation amido/amino mode that involves [1,2]-activation of CO2 and dearomatization/aromatization mode that involves [1,3]-activation of CO2. We also compare their catalytic activity for CO2 hydrogenation. [ABSTRACT FROM AUTHOR]

We report a C−C bond‐forming reaction between benzyl alcohols and alkynes in the presence of a catalytic amount of KOtBu to form α‐alkylated ketones in which the C=O group is located on the side derived from the alcohol. The reaction proceeds under thermal conditions (125 °C) and produces no waste, making the reaction highly atom efficient, environmentally benign, and sustainable. Based on our mechanistic investigations, we propose that the reaction proceeds through radical pathways. Waste not, want not: Benzyl alcohols underwent C−C bond formation with alkynes under thermal conditions in the presence of a catalytic amount of KOtBu to provide α‐alkylated ketones with 100 % atom economy (see scheme). The reaction showed unusual regioselectivity to give products in which the C=O group was located on the side of the molecule derived from the alcohol. [ABSTRACT FROM AUTHOR]

Oxidative addition of aliphatic alcohols to (C(sub 8)H(sub 14))IrCl(Pme(sub 3))(sub 3) in benzene yields the cis-hydridoalkoxo products mer-cis-Hlr(OR)Cl(PM(sub 3))(sub 3) (R = Me, Et, 1-pentyl, 2-propyl). The analogous hydroxo complex is prepared by oxidative addition of water in THF and the addition rate depends on the nature of the alcohol (methanol > 1-pentanol >> 2-propanol and methanol > water).