Vanadium Alumanyl Complex: Synthesis, Characterization, Reactivity, and Application as a Catalyst for C-H Alumanylation of Alkenes.

A complex containing a V-Al bond is described. This species can be prepared by either transmetalation of a previously disclosed alumanylpotassium with CpVCl or photolytic oxidative alumination of CpV using the corresponding dialumane. Reaction of the resulting V-Al complex with H gave a CpV-dihydridoaluminate complex.

Tellurolate: an effective Te-atom transfer reagent to prepare the triad of group 5 metal bis(tellurides).

We show in this work how lithium tellurolate Li(X)TeCHSiMe (X = THF, = 1, 1; X = 12--4, = 2, 2), can serve as an effective Te-atom transfer reagent to all group 5 transition metal halide precursors irrespective of the oxidation state. Mononuclear and bis(telluride) complexes, namely (PNP)M(Te) (M = V; Nb, 3; Ta, 4; PNP = N[2-PPr-4-methylphenyl]), are reported herein including structural and spectroscopic data. Whereas the known complex (PNP)V(Te) can be readily prepared from the trivalent precursor (PNP)VCl, two equiv.

Ditelluride, Terminal Tellurido, and Bis(tellurido) Motifs of Titanium.

Highly modular and rational syntheses of titanium compounds containing ditelluride, terminal telluride, and bis(telluride) structural motifs are disclosed in this study. Titanate anions bearing two and terminal telluride functionalities bound to the same metal center represent a unique example of a group 4 transition metal bis(chalcogenide) ion and are accessed in a simple, single-step procedure from Ti(III) bis(alkyl) complexes in the presence of an outer-sphere reductant and at least 3 equiv of Te powder. These compounds have been characterized crystallographically and spectroscopically with some preliminary reactivity reported for the anionic Ti(═Te) motif.

Tebbe-like and Phosphonioalkylidene and -alkylidyne Complexes of Scandium.

The bonding between scandium and carbon in a series of alkylidene- and alkylidyne-like moieties is compared. The Tebbe analogue complex (PNP)Sc(μ-CHSiMe)(μ-CH)[Al(CH)(CHSiMe)] () (PNP = N[2-PPr-4-methylphenyl]) could be formed by adding AlMe to (PNP)Sc(CHSiMe) (). The fluxional behavior of is studied by a combination of 2D C-H HMQC, HMBC, and other heteronuclear NMR spectroscopic experiments.

Conversion of methane to ethylene using an Ir complex and phosphorus ylide as a methylene transfer reagent.

Cp*(Me3P)Ir(CH3)(OTf), a complex known to reversibly activate CH4 and other hydrocarbons under mild conditions, reacts with the phosphorus ylide H2CPPh3 in THF to afford two major species [Cp*(Me3P)(Ph3P)Ir(CH2CH3)][OTf] and [Cp*(Me3P)Ir(H)(η2-CH2CH2)][OTf]. Insertion of the ylide methylene group can also occur with Cp*(Me3P)Ir(Ph)(OTf) to afford the benzyl [Cp*(Me3P)(Ph3P)Ir(CH2Ph)][OTf]. Theoretical studies suggest the intermediacy of an Ir(iii)[double bond, length as m-dash]CH2 species.

Reactivity of heavy carbene analogues towards oxidants: a redox active ligand-enabled isolation of a paramagnetic stannylene.

o-Phenylenediamido Pb(ii) and Sn(ii) complexes react with mesityl azide in analogous C-H activation reactions. The Pb(ii) complex forms a Lewis pair with ONMe. The Sn(ii) analogue reacts with AgOTf yielding a paramagnetic stannylene; such compounds have been previously observed in situ, but hitherto have not been isolated.

Reactions of Boron-Derived Radicals with Nucleophiles.

Reactions of phenanthrenedione- and pyrenedione-derived borocyclic radicals, CHOB(CF) (n = 14 (1), 16 (3)), with a variety of nucleophiles have been studied. Reaction of 1 with P(t-Bu) affords the zwitterion 3-(t-Bu)PCHOB(CF) (5) in addition to the salt [HP(t-Bu)][CHOB(CF)] (6). In contrast, the reaction of 1 with PPh proceeds to give two regioisomeric zwitterions, 1-(PhP)CHOB(CF) (7a) and 3-(PhP)CHOB(CF) (7b), as well as the related boronic ester CHOB(CF) (2).