Cationic copper (I) complexes with bulky 1,4-diaza-1,3-butadiene ligands – Synthesis, solid state structure and catalysis

Synthesis of Indoles and Benzofurans Using a Graphene Oxide-Grafted Aminobisphosphine-PdII Complex

Indoles and benzofurans have been synthesized using a graphene oxide-grafted aminobisphosphine-Pd^II complex (GO@PNP-Pd) under copper-free condition. A range of indole and benzofuran derivatives have been made by the reaction of N-protected 2-iodoanilines and 2-iodophenols with terminal acetylenes in presence of GO@PNP-Pd. The activity of the aminobisphosphine-Pd^II complex remains the same under both homogeneous and heterogeneous conditions. Finally, the recycling ability of the immobilized catalyst (GO@PNP-Pd) has been examined for five consecutive runs with appreciable conversion.

Alkali metal complexes having sterically bulky bis-iminopyrrolyl ligands – control of dimeric to monomeric complexes

Alkali metal salts of {(CHPh₂)₂-pyr} and {(CPh₃)₂-pyr} were prepared and in the molecular structures of these complexes a nuclearity shift from the dimer to monomer were observed due to the substitutions of CHPh₂ to CPh₃ groups in imine nitrogen of the ligand.

Titanium and zirconium complexes of the N,N'-bis(2,6-diisopropylphenyl)-1,4-diaza-butadiene ligand: syntheses, structures and uses in catalytic hydrosilylation reactions

We report here a number of dianionic 1,4-diaza-1,3-butadiene complexes of titanium and zirconium synthesised by a salt metathesis reaction. The reaction of either CpTiCl3 or Cp2TiCl2 with the dilithium salt of N,N'-bis(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene [; abbreviated (Dipp)2DADLi2] afforded the mono-cyclopentadienyl titanium complex [η(5)-CpTi((Dipp)2DAD)Cl] () bearing a dianionic ene-diamide ligand, while the analogous reaction of zirconocene dichloride (Cp2ZrCl2) with the dilithium salt gave the bis-cyclopentadienyl zirconium complex [Cp2Zr{(Dipp)2DAD}] (). The metal dichloride complexes [Ti((Dipp)2DAD)Cl2] () and [{(Dipp)2DADZrCl(μ-Cl)}2(κ(3)-Cl)(Li)(OEt2)2] () were obtained by the reaction of and anhydrous metal tetrachloride in a 1 : 1 molar ratio in diethyl ether at room temperature. Meanwhile, the homoleptic titanium complex [Ti{((Dipp)2DAD)}2] () was isolated in good yield by the treatment of with TiCl4 in a 1 : 2 molar ratio in diethyl ether. The complexes and were further reacted with neosilyl lithium to afford mono- and bis-alkyl complexes of titanium [η(5)-CpTi{(Dipp)2DAD}(CH2SiMe3)] () and zirconium [Zr{(Dipp)2DAD}(CH2SiMe3)2] () respectively. Molecular structures of the complexes , , and in the solid states were confirmed by single crystal X-ray diffraction analysis. The solid state structures of all the complexes reveal that the metal ions are chelated through the amido-nitrogen atoms and the olefinic carbons of the [(Dipp)2DAD](2-) moiety, satisfying the σ(2),π coordination mode. Compound was used as a catalyst for the intermolecular hydrosilylation reaction of a number of olefins, and moderate activity of catalyst was observed.

Synthesis, structure and reactivity study of magnesium amidinato complexes derived from carbodiimides and N,N'-bis(2,6-diisopropylphenyl)-1,4-diaza-butadiene ligands

We report an amidinato ligand-supported series of magnesium complexes obtained from the insertion of a magnesium-carbon bond into a carbon-nitrogen double bond of different carbodiimides and α-diimine ligands. The magnesium complexes [Mg(CH2Ph){CyN[double bond, length as m-dash]C(CH2Ph)NCy}]2 (), [Mg(CH2Ph){(i)PrN[double bond, length as m-dash]C(CH2Ph)N(i)Pr}]2 () and the homoleptic [Mg{(t)BuN[double bond, length as m-dash]C(CH2Ph)N(t)Bu}2] () (Cy = cyclohexyl, (i)Pr = isopropyl, (t)Bu = tert-butyl) were prepared by the reaction of dibenzyl magnesium [Mg(CH2Ph)2(Et2O)2] with the respective carbodiimides either in 1 : 1 or 1 : 2 molar ratio in toluene. The analogous reaction of [Mg(CH2Ph)2(Et2O)2] with the N,N'-bis(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene (Dipp2DAD) ligand afforded the corresponding homoleptic magnesium complex [Mg{DippN[double bond, length as m-dash]C(CH2Ph)CH2NDipp}2] () (Dipp = 2,6 diisopropylphenyl) in good yield. The solid-state structures of magnesium complexes were confirmed by single-crystal X-ray diffraction analysis. It was observed that in each case, a magnesium-carbon bond was inserted into the carbon-nitrogen double bond of either carbodiimides or Dipp2DAD resulting in a monoanionic amido-imino ligand. In a further reaction between and N-aryliminopyrrolyl ligand 2-(2,6-(i)Pr2C6H3N[double bond, length as m-dash]CH)C4H3NH (ImpDipp-H) in 1 : 2 molar ratio, a new magnesium complex [Mg(ImpDipp)2{CyN[double bond, length as m-dash]C(CH2Ph)NHCy}] (), with one amidinato and two aryliminopyrrolyl ligands in the coordination sphere, was obtained in good yield. In contrast, the homoleptic magnesium complex reacted with one equivalent of N-aryliminopyrrolyl ligand (ImpDipp-H) to produce another mixed ligated magnesium complex [Mg{DippN[double bond, length as m-dash]C(CH2Ph)CH2NDipp}(ImpDipp)] (), with a benzylated DAD ligand and aryliminopyrrolyl ligands in the coordination sphere. Further reaction of complex with benzyl alcohol (PhCH2OH) afforded the third mixed ligated magnesium complex [Mg{DippN[double bond, length as m-dash]C(CH2Ph)CH2NDipp}(OCH2Ph)2] () in very good yield. The magnesium complexes were characterised using standard analytical/spectroscopic techniques and their solid-state structures were established by single-crystal X-ray diffraction analysis.