Linear Connection of Four Nitrile Molecules on the Tetraphosphine Complexes of Tungsten and Molybdenum

Abstract

The tetrahydride complex [WH4(κ4-P4)] (P4 = meso-o-C6H4­(PPhCH2CH2PPh2)2) reacts with ArFCN (ArF = 3,5-(CF3)2C6H3) in toluene at 80 °C to give [W(κ3-NCArFCArFNCArF­NCArFN)(κ3-P4)]. The X-ray crystallographic study has revealed that four ArFCN molecules are connected linearly in the sequence NCCNCNCN. The resulting organic moiety is bound to the W center as a tridentate N-donor in a meridional fashion and constitutes a metallacyclic system containing fused five- and six-membered rings. The Mo analogue can be prepared by the reaction of [Mo(η4-1,5-cyclooctadiene)­(κ4-P4)] with excess ArFCN.

Reactions of Dianionic α-Diimine-Supported Dimagnesium(I) Compound [K(THF)3]2[LMg–MgL] with Nitriles

“…There are also homo- and hetero- (with other groups such as CC bond) C–C couplings, e.g., reductive C–C coupling of two coordinated nitriles to form a five-membered metallocycle (type D in Chart ). − Besides these reaction routes, sometimes nitrile isomerization can occur to afford an isonitrile, which then coordinates to metal through the carbon atom or undergoes C–C coupling process…”

Activation of C–H Bonds of Alkyl- and Arylnitriles by the TaCl5–PPh3 Lewis Pair

“…These reactions can lead to metallacycles and bridged bimetallic complexes. Cyclic products are formed by the reductive C–C coupling of two coordinated nitriles, often leading to five-membered metallacycles. − Two-electron reduction per two nitriles has been shown to result in the formation of the bridging diiminato ligand upon dimerization of nitriles adducts of low-valent metal centers. − This process involves reduction of a coordinated nitrile by a metal center with the formation of a radical, which then dimerizes with another equivalent of its congener to form the single C–C bond. Four-electron reduction of two nitrile ligands by low-valent Group 4–6 complexes led to formation of enediimido species related to 2 . − In those instances, the CC double bond is formed between two nitriles, which may be considered as a stepwise reduction to first form a diazavinylidene moiety that is further reduced by two metal centers to form the bridging enediimido group.…”

Reactivity of a magnesium diboranate with organic nitriles

“…Scheme 4: Synthesis of compound 3. route to a variety of silyl aza-allyl and -diketiminate species, 63,64 while there is ample precedent for C=C and C-C bond formation between nitrile sp-carbon centres at a variety of low oxidation early transition metal and main group element centres. [65][66][67][68][69][70][71][72][73][74][75][76] nitrile-nitrile C-C dimerisation leading to metalla-1,4-diaza-butadiene complexes is a quite well precedented process. [65][66][67][68][69][70][71][72][73][74][75][76] To the best of our knowledge, however, the only previous report of nitrile C- 62,78 The N4 atom of the borylamide anion is also bonded to a 2,4,5-tri-o-tolyl-2H-imidazole unit [N4-C38…”