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Thereaction of transient [MeP-W(CO)5] with norbornene givesthe two corresponding exophosphiranes with W synor antito the norbornane bridge. The syncomplex is selectively decomplexed by carbon monoxideat 120 °C under 50 bar. Both complexes are easily cleaved byPd(OAc)2at room temperature to give [MeP(OAc)2)]W(CO)5. [ABSTRACT FROM AUTHOR]

A 1,2‐dihydrophosphination of bis(phenylphosphino)ethane with a wide range of activated olefins was achieved in a catalytic manner with enantiomeric and diastereomeric excess of up to >99% and 44% respectively. The protocol can be extended to selected substrates leading to free P‐ and C‐chiral 1,2‐diphosphines. The synthesized ligands can also undergo direct complexation onto palladium affording complexes with complete retention of stereo‐integrity. [ABSTRACT FROM AUTHOR]

A metal-free tandem double hydrophosphination of extended conjugated indandiones has been established. Mechanistic investigations confirmed the consecutive manner of the nucleophilic addition reaction. Complexation of the generated keto-diphosphine resulted in the formation of an unexpected tridentate bridging ligand with an anionic P,O-bidentate and a neutral P-monodentate coordination mode on two palladium units. In the presence of an external chiral auxiliary, the coordinated diphosphines could be separated into their enantiomeric forms. [ABSTRACT FROM AUTHOR]

Given the periodic relationship of phosphines and arsines, is remodeling the catalytic asymmetric hydrophosphination reaction an efficient manner to develop the corresponding hydroarsination reaction? Herein, a chiral PCP-Pd(ii) pincer complex adept at generating enantioenriched phosphines was examined in the asymmetric hydroarsination reaction. Under distinct conditions, tertiary phosphines and arsines were generated in excellent yields (P: 96%, As: 91%) and ees (P: 90%, As: 85%). While secondary arsine reagents were not direct substitutes for the analogous phosphines, important parameters were identified which increased yield and ee of the hydroarsination reaction. Unlike the PCP-PdOAc pincer complex commonly used for hydrophosphinations, hydroarsination reactions involved a PCP-PdCl catalyst with 10 equiv. of CsF for optimal performance. Notable differences between the two reactions and their workup procedures were highlighted to guide further developments in the field. Lastly, respective mechanisms were proposed and contrasted for the activation of HEPh2 (E = P, As). [ABSTRACT FROM AUTHOR]

The palladacycle-catalyzed asymmetric PH addition of 4- oxo-enamides has been developed, which provides efficient access to phosphinocarboxamides and their analogues. Solvent-mediated reversal of stereoselectivity ( ee from +96 % to −92 %) was observed, and the underlying mechanism that allows facile access to both enantiomers of the product by judicious choice of solvents is revealed. [ABSTRACT FROM AUTHOR]

An organopalladium complex containing ortho-metalated (R)-(1-(dimethylamino) ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric hydrophosphination reaction between diphenylphosphine and phenyldi[(Z)-prop-1-enyl]phosphine in high regio- and stereoselectivity under mild conditions. The hydrophosphination reaction generated only two diastereomers in a ratio of 1:1. The two hydrophosphination products contained both phosphorus and carbon stereogenic centers and were subsequently isolated by fractional crystallization. Their absolute stereochemistries were analyied by X-ray crystallography. The naphthylamine auxiliary could be removed chemoselectively from the template products by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral dichloro complexes. Subsequently, the dichioro complexes underwent ligand displacement with aqueous cyanide to generate the optically pure diphosphine ligands in high yields. [ABSTRACT FROM AUTHOR]

Understanding the electrocatalytic activity at single nanoparticles/nanoclusters level is extremely important. In this work, a method for the electro‐deposition of single Pt–Pd nanoparticles (NPs) is described using a single nanopore electrode as a template. The electro‐deposition process was investigated carefully and the results show that the process is controlled by diffusion and electro‐crystallization process, simultaneously, and the glass sheath property around the nanopore has a large impact on the formation of single Pt–Pd NPs due to the "edge effect". The prepared single Pt–Pd NPs exhibit excellent electrocatalytic activity in the methanol oxidation reaction, which can be used to screen electrocatalysts with high efficiency for utility in the energy field. Living on the edge: Single Pt–Pd nanoparticle (NPs) electrode was fabricated by an electro‐deposition method using a single nanopore electrode as a template, which was controlled by the "edge effect." The prepared single Pt–Pd NPs exhibit excellent electrocatalytic activity towards methanol oxidation reaction, which can be used to screen electrocatalysts with high efficiency for utility in the energy field. [ABSTRACT FROM AUTHOR]

The catalytic hydrophosphination reaction is one of the most sustainable chemical transformations today. Here, the palladium-catalyzed asymmetric PH addition of diarylphosphines with N-enoylbenzotriazoles and analogues is described. Chiral phosphine products are obtained in 100% atom economy and without cumbersome protection-deprotection manipulations. The obtained products can be subsequently transformed to bear various functionalities, including phosphino-carboxylic esters which play critical roles in catalysis and as synthetic aids. Anti-tumour activities of the corresponding gold-phosphine complexes have been explored, contributing to existing chemotherapeutic research in cancer treatment. [ABSTRACT FROM AUTHOR]

Two structurally isomeric substituted N, N-dimethylethanamines have been prepared. Treatment of the 2,4-di- tert-butylphenyl isomer with PdII ions generated the ortho-metalated complexes. On the other hand, treatment of the 2,5-di- tert-butylphenyl-substituted amine resulted in the unexpected chemoselective cleavage of one of the three N-C bonds, thus generating the corresponding secondary amine. The N-demethylation process could be catalyzed at room temperature by palladium(II) catalysts such as PdCl2 or Pd(OAc)2. Furthermore, treatment with a stoichiometric amount of PdII ions gave a metal complex in which both secondary amines were bound to Pd in an N-monodentate fashion. When triethylamine was introduced, one of the N-ethyl groups in NEt3 was cleaved, and an unexpected heteroamine complex was produced. The products generated were isolated and characterized by X-ray crystallography. Mechanistic insights into the cyclometalation and C-N cleavage observed are discussed. [ABSTRACT FROM AUTHOR]

Phenylbis(phenylethynyl)phosphane PhP(C≡CPh)2 coordinates regiospecifically to the α-methyl-chiral ortho-platinated and -palladated naphthylamine units at the positions trans to the nitrogen donors. The P→Pt coordination bond is kinetically inert, whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd-C bond insertion reaction with an external ortho-palladated naphthylamine ring. No intramolecular insertion reaction occurred. In contrast to its palladium analogue, the ortho-platinated ring is not reactive towards coordinated PhP(C≡CPh)2, although it can promote the Pd-C bond insertion reaction. However, despite the high kinetic stability of the P→Pt coordination, the organoplatinum unit is a noticeably weaker activator than its organopalladium counterpart. The chirality of the reacting ortho-metallated naphthylamine ligand exhibited high stereochemical influence on the formation of the new stereogenic phosphorus center during the course of these C-C bond-formation reactions. The coordination chemistry and the absolute stereochemistry of the dimetallic products were determined by single-crystal X-ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

Palladium and platinum complexes containing a sulfur-functionalised N-heterocyclic carbene (S-NHC) chelate ligand have been synthesised. The absolute conformations of these novel organometallic S-NHC chelates were determined by X-ray structural analyses and solution-phase 2D 1H-1H ROESY NMR spectroscopy. The structural studies revealed that the phenyl substituents on the stereogenic carbon atoms invariably take up the axial positions on the Pd-C-S coordination plane to afford a skewed five-membered ring structure. All of the chiral complexes are structurally rigid and stereochemically locked in a chiral ring conformation that is either ( Rs, S, R)-λ or ( Ss, R, R)-δ in both the solid state and solution. [ABSTRACT FROM AUTHOR]

In intermolecular Heck reactions of styrene and vinylarenes, the aryl and vinyl groups routinely insert at the β position. However, selective insertion at the α position has been very rare. Herein, we provide a missing piece in the palette of Heck reaction, which gave >20:1 α selectivity. The key to our success is a new ferrocene 1,1′-bisphosphane (dnpf) that carries 1-naphthyl groups. Our mechanistic studies revealed that the high α selectivity is partly attributable to the steric effect of dnpf. The rigid and bulky 1-naphthyl groups of dnpf sterically disfavor β insertion. [ABSTRACT FROM AUTHOR]

Different enol acetates are treated with aryl and vinyl triflates as well as aryl halides in the presence of chiral phenoxy-substituted ligands (I). [ABSTRACT FROM AUTHOR]