CuII Salts Research Articles

3-(Arylhydrazono)pentane-2, 4-diones and their Complexes with Copper(II) and Nickel(II) ? Synthesis and Crystal Structures

A series of new 3-(arylhydrazono)pentane-2, 4-diones (1-6) synthesized from pentane-2, 4-dione and diazonium salts of respective anilines using the procedure of Japp-Klingemann are described. Complexes with CuII and NiII salts are prepared (7-10, respectively). Spectroscopic properties of these compounds have been studied and X-ray crystal structures of selected hydrazones (3, 4, 6) and of the hydrazone complexes (7-10) are reported. The structures of the uncomplexed hydrazones feature an intramolecular N-H···O interaction to yield a six-membered H-bond ring reflecting preference of the hydrazone tautomeric structure. All the complexes are mononuclear 2:1 (L:M) structures of six-membered chelate type involving N2O2 binding sites that are quadratic arranged but differ in the entire coordination environment dependent on the metal and the ligand substitution including distorted octahedral and quadratic pyramidal coordination geometries in the CuII complexes 7 and 8 or nearly regular square planar coordination geometry in the NiII complexes 9 and 10, respectively. In the crystal packings, strong and weak H-bond interactions cause supramolecular network structures.

Aggregation of [Cu${{\bf }{{{\bf II}\hfill \atop \bf 4\hfill}}}$] Building Blocks into [Cu${{\bf }{{{\bf II}\hfill \atop \bf 8\hfill}}}$] Clusters or a [Cu${{\bf }{{{\bf II}\hfill \atop \bf 4\hfill}}}$]∞ Chain through Subtle Chemical Control

AbstractCoordination complexes of the ligand H3L [1,3‐bis(3‐oxo‐3‐phenylpropionyl)‐2‐hydroxy‐5‐methylbenzene] with CuII are reported. Clusters showing various nuclearities or modes of supramolecular organization have been prepared by slightly changing the reaction conditions and have been crystallographically characterized. The reaction of H3L with one equivalent of Cu(OAc)2 in DMF yields the dinuclear complex [Cu2(HL)2(dmf)2] (1). Reaction in MeOH of H3L with an increased amount of metal, in the form of Cu(NO3)2, and excess strong base (nBu4NOH) affords the cluster [Cu8(L)2(OMe)8(NO3)2] (2). Complex 2 is a dimer of two linear [Cu4] arrays bridged by methoxide ligands, where the polynucleating ligand is fully deprotonated. The [Cu4]2 clusters are linked to each other by NO3− bridges to form one‐dimensional coordination polymers. The link between [Cu8] units and their relative spatial positioning can be modified by changing the anion of the CuII salt, as demonstrated by the synthesis of the cluster polymers [Cu8(L)2(OMe)8Cl2] (3) and [Cu8(L)(OMe)7.86Br2.14] (4), where only NO3− has been replaced by Cl− or Br−, respectively. Similarly, when ClO4− is used, compound [Cu8(L)2(OMe)8(ClO4)2(MeOH)4] (5) can be isolated. It contains independent [Cu8] units. A slight change in the stoichiometry of the reaction leading to 2 affords the related complex catena‐[Cu4(L)(OMe)3(NO3)2(H2O)0.36] (6). This polymer contains essentially the same [Cu4] moiety as 2, albeit organized in a completely different arrangement. Each [Cu4] unit in 6 is linked by OMe− ligands to two such equivalent groups to form an infinite chain. Magnetic susceptibility measurements reveal weak antiferromagnetic exchange between CuII centers in 1 (J = −0.73 cm−1) and strong antiferromagnetic coupling within [Cu4] chains in 2, 5, and 6 (most negative J values of −113.8 and −177.3 cm−1 for 2 and 6, respectively).

Intramolecular γ‐Hydroxylations of Nonactivated CH Bonds with Copper Complexes and Molecular Oxygen

Copper(I) complexes incorporating the isomeric bidentate ligands IMPY (iminomethyl-2-pyridines) or AMPY (aminomethylene-2-pyridines) are quite unusual in their ability to bind and activate molecular oxygen. Using these complexes, hydroxylations of nonactivated CH, CH2, or CH3 groups in the gamma-position in relation to the imino-nitrogen atom, and with a specific orientation of one H atom with respect to the binuclear Cu-O species, can be achieved in synthetically useful yields. Through mechanistic studies employing conformationally well-defined molecules (for example, cyclic isoprenoids), coupled with solid-state X-ray structure analyses and force-field calculations, we postulate a seven-membered transition state for this reaction in which six atoms lie approximately in a plane. This plane is defined by the positions of the lone pairs on the nitrogen atoms, as well as the copper and the oxygen atoms. For a successful hydroxylation, one hydrogen atom should be located close to this plane. Prediction of the stereochemical course of these reactions is possible based on a simple geometrical criterion. The convenient introduction of IMPY and AMPY groups as auxiliaries into oxo and primary amino compounds and the simple hydrolysis after the hydroxylation procedure has allowed the synthesis of 3-hydroxy-1-oxo and 3-hydroxy-1-amino compounds. If desired, the 3-hydroxy-1-IMPY and -1-AMPY compounds can be reduced with NaBH4 to obtain 3-hydroxy-1-aminomethylpyridines. For a successful hydroxylation procedure, the method employed for the synthesis of the CuI complexes is very important. Starting either from CuI salts or from CuII salts with a subsequent reduction with benzoin/triethylamine may turn out to be the better way, depending on the ligand and the molecular structure.

Cluster cyanide-bridged heterometallic coordination polymers: synthesis and crystal structures of compounds [{Cu2(dien)2(CN)}2{Mo4Te4(CN)12}]·14.5H2O and (H3O)3K[{Mn(H2O)2}2{Mn(H2O)2(NO3)}4{W4Te4(CN)12}2]·8H2O

The reactions of anionic molybdenum and tungsten cyanide cuboidal clusters with CuII and MnII salts afforded two new cyanide-bridged heterometallic coordination polymers with the composition [{Cu2(dien)2(CN)}2{Mo4Te4(CN)12}]⋅14.5H2O (1) and (H3O)3K[{Mn(H2O)2}2{Mn(H2O)2(NO3)}4{W4Te4(CN)12}2]·8H2O (2). The structures of these compounds were established by X-ray diffraction analysis. Compound 1 has a layered structure, in which the cuboidal cluster fragments {Mo4Te4(CN)12}6− are linked to the copper atoms of the dinuclear fragments {(H2O)(dien)Cu(μ-CN)Cu(dien)(H2O)} through the bridging CN groups. Coordination polymer 2 has a framework structure, in which the cluster fragments {W4Te4(CN)12}6− are linked to the manganese(II) aqua complexes of two types, viz., the dinuclear fragment {Mn(μ2-H2O)2Mn} and the tetranuclear cyclic fragment {(H2O)2Mn(μ2-NO3)}4, through the bridging CN groups.

Synthesis, characterization and redox properties of a new vic-dioxime and its transition metal complexes

A novel vic-dioxime, 1,2 dihydroxyimino-1-p-tolyl-3-aza-6-morpholine heptane (LH2) was prepared by reacting anti-p-tolylchloroglyoxime with 4-(3-aminopropyl)morpholine in absolute THF. Mononuclear complexes with a metal–ligand ratio of 1:2 were prepared using CoII, CuII and NiII salts. The ligand and its complexes were characterized by elemental analyses, FT-IR, u.v.–vis., 1H- and 13C-n.m.r. spectra, magnetic susceptibility measurements, thermogravimetric analyses (t.g.a.), and by cyclic voltammetry.

Complexes of 2, 6‐Bis(hydroxymethyl)pyridine with Different Copper(II) Salts Involving the Anions Chloride, Perchlorate, Nitrate and Acetate. Synthesis and Crystal Structures of the Complexes

AbstractComplexes of 2, 6‐bis(hydroxymethyl)pyridine (dhmp) with different CuII salts [CuCl2·6H2O, Cu(ClO4)2·6H2O, Cu(NO3)2·3H2O, Cu(CH3COO)2·H2O] are prepared (1—5, respectively), studied by IR, and their crystal structures reported. Dependent on the anion kind, influences on the distortion of the co‐ordination polyhedron, the distribution of donor sites, the formation of a mono‐ or binuclear complex, and the resultant packing structure of the complex are observed, although in no case the counterions of the used CuII salts or water of hydration were found in the co‐ordination sphere. Crystal structures of 1—5 indicate hexaco‐ordination of the CuII ions with N2O4‐environment and show that 1—4 are mononuclear 2:1 (L:M) complexes, but 5 is a binuclear 4:2 complex. Crystallization of Cu(ClO4)2·6H2O with dhmp yielded two different complexes (2/3). In 3, one of the dhmp components is mono‐deprotonated and acts as an anionic ligand. The same behavior is found in 5. Whereas in the neutral ligand complexes 1, 2 and 4 the basal planes are occupied by O donors, and N atoms are in the axial positions of the octahedrons, in 3 and 5 the bases are formed by two O and two N donor atoms, and O atoms are in the axes. Moreover, complex 3 shows the N atoms in trans position, but 5 in cis position. The packing of the cationic complex units is typical of strong and weak H bond interactions involving the counterions and hydroxylic or aromatic hydrogen atoms to yield complex network structures.

Liquid Crystals ofN,N‘-Dialkylimidazolium Salts Comprising Palladium(II) and Copper(II) Ions

Metal-containing ionic liquid crystals of N,N‘-dialkylimidazolium salts of PdII and CuII ([(CnH2n+1)2-im][MCl4], n = 8, 10, 12, 14, 16, and 18 for M = PdII and n = 10, 12, 14, 16, and 18 for M = CuII) were prepared. Crystal structures of two compounds, [(C12H25)2-im]2[PdCl4] and [(C12H25)2-im]2[CuCl4]·H2O, have been characterized by single crystal X-ray diffraction. The cations of these two compounds adopt a U-shaped conformation and are packed in a highly interdigitated bilayer fashion. The square planar PdCl42- and distorted tetrahedral CuCl42- are sandwiched between the cationic bilayers individually. Both series of compounds exhibit a wide temperature range of SmA mesophase. Thermal decompositions are observed near the clearing tempertures. For the PdII series, decomposition generates palladium dicarbene and carbene-imidazole complexes. Ionic liquid crystals with different combinations of [(C18H37)2-im]2[PdCl4], [(C18H37)2-im]2[CuCl4]·H2O, and [(C18H37)2-im]Cl·H2O are good candidates for PdII/CuII catalyzed reactions carried out under partially ordered environments of ionic liquids.

Synthesis, characterization and antimicrobial activity of the Schiff bases derived from 2,4-disubstituted thiazoles and 3-methoxysalicylaldehyde, and their cobalt(II), copper(II), nickel(II) and zinc(II) complexes

Two new Schiff base ligands containing 2,4–disubstituted thiazoles and cyclobutane rings, 4-(1-methyl-1-phenylcyclobutane-3-yl)-2-(2-hydroxy-3-methoxybenzylidenehydrazino)thiazole (L1H), 4-(1-methyl-1-p-xylylcyclobutane-3-yl)-2-(2-hydroxy-3-methoxybenzylidenehydrazino)thiazole (L2H) and their mononuclear complexes with a 1:2 metal–ligand ratio have been prepared from acetate salts of CoII, CuII, NiII and ZnII in EtOH. The authenticity of the ligands and their complexes have been established by microanalyses, i.r., 13C- and 1H-n.m.r. spectra, and by magnetic susceptibility and conductivity measurements. The complexes are mononuclear. Thermal properties of the ligands and complexes have been studied by t.g.a. and d.s.c. techniques. Antimicrobial activities of the ligands and their complexes have been tested against six different microorganisms; three are yeast and three are bacteria. One of the ligands and many of the complexes were found to be active against some of the microorganisms studied.

From metallacyclophanes to 1-D coordination polymers: role of anions in self-assembly processes of copper(II) and 2,5-bis(3-pyridyl)-1,3,4-oxadiazole.

The reaction of various CuII salts with 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (L) in CH3CN-H2O medium affords different complexes, the solid structures of which are controlled only by the choice of the counteranions. Reaction of Cu-(ClO4)2.6H2O or Cu(NO3)2.3H2O and L yields the novel bimetallic macrocyclic complex [Cu2L2(H2O)6](ClO4)4(H2O)4 (1) [monoclinic, space group P21/m, a = 8.745(5) A, b = 16.179(10) A, c = 14.930(8) A, beta = 93.253(10) degrees, Z = 2] or [CuL(NO3)2]2(CH3CN)2 (2) [triclinic, space group P1, a = 7.863(3) A, b = 8.679(3) A, c = 13.375(5) A, alpha = 74.121(5) degrees, beta = 78.407(6) degrees, gamma = 86.307(6) degrees, Z = 1]. However, with the replacement of CuII perchlorate or nitrate salts with CuSO4.5H2O or Cu(OAc)2.H2O in the above reaction, two different one-dimensional (1-D) coordination polymers [[Cu2L2(H2O)6(SO4)2](H2O)6]n (3) [triclinic, space group P1, a = 7.078(3) A, b = 11.565(4) A, c = 12.561(5) A, alpha = 109.511(6) degrees, beta = 105.265(6) degrees, gamma = 94.042(6) degrees, Z = 1] or [[Cu2L(mu-OAc)4]]n (4) [monoclinic, space group C2/c, a = 20.007(7) A, b = 7.506(2) A, c = 16.062(5) A, beta = 108.912(5) degrees, Z = 4] were obtained. These results unequivocally indicate that the nature of the counteranions, which play different roles in each complex, is the key factor governing the structural topologies of them. The magnetic properties of these CuII complexes have been investigated by variable-temperature magnetic susceptibility and magnetization measurements, and the magneto-structural correlation has been analyzed in detail.

Dioxygen Activation Using Schiff Base Macrocyclic Dinuclear Copper( I ) Complexes: Structurally Characterized Dioxygen Reaction Products

Schiff-base condensation of diethylenetriamine with a series of dialdehydes [isophthalaldehyde (2a), 5-tert-butylisophthalaldehyde (2b), 2-methylisophthalaldehyde (2c), and p-phthalaldehyde (2d)] affords four hexaaza macrocyclic ligands [LH,H (3a), LtBu,H (3b), LH,Me (3c), Lp-H,H (3d)] bearing different substituents on the aromatic units that connect the two metal ion binding sites. The dinuclear copper(I) complexes [LH,HCu2(MeCN)2](ClO4)2 (4a), [LtBu,HCu2(MeCN)2](ClO4)2 (4b), [LH,MeCu2(MeCN)2](ClO4)2 (4c), and [Lp−H,HCu2(MeCN)2](CF3SO3)2 (4d) are obtained in good yields by reaction with CuI salts. X-ray diffraction studies performed on 4a and 4d reveal a distorted tetrahedral coordination geometry around each CuI ion, which is constructed by three nitrogen donors of the macrocyclic ligand and one acetonitrile solvent molecule. Treatment of these complexes with molecular dioxygen shows that their reactivity can be fine-tuned by the nature of the aromatic unit of the dialdehyde building blocks. Thus two different dinuclear CuII complexes resulting from the reaction of 4a and 4b with dioxygen were isolated and characterized by single crystal X-ray diffraction, XPS and magnetic measurements. The introduction of a methyl group in the 2-position of the aromatic spacers in 4c hinders such oxygen transfer reactions but may allow the characterization of stable dioxygen binding species. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Aqueous room temperature metal-catalyzed living radical polymerization of vinyl chloride.

This paper describes the room-temperature living radical polymerization (LRP) of vinyl chloride in H2O/THF in the presence of Cu0 or CuI salts as catalysts, tren or PEI as ligands, and iodoform as initiator. The disproportionation reaction 2CuI + L --> Cu0 + CuII(L) is the crucial step, as it continuously provides the active species for both the initiation (Cu0) and the reversible termination step (CuII). Mn was found to increase linearly with conversion and is in good agreement with Mth, with the Mw/Mn being approximately 1.5.

Spin exchange between transition metal complexes and nitroxyl radicals in nonaqueous media

New complexes of diaza- and tetraaza-containing crown ethers, viz., 1,10-diaza-18-crown-6 (1), 1,4,8,12-tetraazacyclopentadecane (2), 1,4,8,11-tetraazacyclotetradecane (3), and 1,4,8,11-tetraazacyclotetradecane 1,4,8,11-tetrachloride tetraacetic acid tetrahydrate (4), with the divalent copper and nickel ions and the Cl–, Br–, ClO4 –, NO3 –, and AcO– counterions were synthesized. The exchange interactions of these compounds and paramagnetic copper and nickel salts with the TEMPO radical in MeOH—CHCl3 binary mixtures of different compositions were studied. The plots of the linewidths of the hyperfine coupling components of TEMPO vs. concentration of the ions and temperature show that the frequency of diffusion collisions is the rate-limiting step for spin exchange (strong exchange regime). A strong dependence of the exchange rate constant (k ex) on the crown ether and counterion structure was found. The isotropic hyperfine coupling constants (a Cu) and g factors (g i ) were measured for the CuII complexes with the crown ethers. In the case of the crown ether complexes 1—3 with CuCl2, the a Cu constant decreases linearly with an increase in Δg i = g i – 2.0023 in the series 3 < 2 < 1, whereas k ex increases linearly in the same series with a decrease in the contact HFC on the CuII nucleus (K) and a decrease in covalence of bonding. For the complexes of 2 with CuII and different axial ligands (counterions), k ex increases in the series Cl– < ClO4 – ≤ AcO– ≤ Br–; < NO3 –. In the case of the complexes of 2 with NiCl2, k ex increases in the series 1 < 4 < 3 ≈ 2. For the CuII and NiII salts with the Cl–, ClO4 –, and NO3 – anions, the k ex values are almost independent of the anion nature. The correlation of the k ex values with the electron-spin parameters of the complexes is discussed.

Thioethynyl esters of phosphorus acids

The results of searching for the methods of synthesis of substituted thioethynyl monothio- and dithiophosphates, which are of interest as physiologically active compounds, are summarized. The preparative method for the synthesis of thioesters of O,O-dialkylmonothiophosphoric acids of a specific type was developed: the reaction of substituted ethynyl bromides with potassium salts of the corresponding monothiophosphoric acids in the presence of an equimolar amount of CuCl. These reactions occur through the stage of formation of CuI salts of the corresponding monothiophosphoric acids and are accompanied by redox processes leading to the formation of free radicals. The modified method for the synthesis of substituted thioethynyl monothio- and dithiophosphates is the reaction of CuI salts of these acids with the corresponding ethynyl bromides.

CuI and CuII salts of group VIA elements as catalysts for living radical polymerization initiated with sulfonyl chlorides

ABSTRACT: The living radical polymerization of methyl methacrylate initiated fromsulfonyl chlorides and catalyzed by the new catalytic systems Cu 2 Y/Bpy and CuY/Bpy,where Y is O, S, Se, or Te and Bpy is 2,29-bipyridine, is described. An induction time wasobserved in all polymerization experiments. The values of the experimental rate con-stants of polymerization ( k p exp ) increased whereas the corresponding induction timesdecreased in the order Y 5 O , S , Se , Te. For the entire series of catalysts, k p exp forCuY was less than k p exp for Cu 2 Y. A mechanistic interpretation that involves the in situ generation of the CuCl/CuCl 2 pair, starting from Cu 2 Y or CuY, is provided. © 2000 JohnWiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3839–3843, 2000 Keywords: living radical polymerization; sulfonyl chloride; methyl methacrylate;copper oxide; copper sulfide; copper selenide; copper telluride; copper chloride INTRODUCTION In a recent series of publications 1 from our labo-ratory, we demonstrated that aryl,

Copper(II) oxalate and oxamate complexes

Reaction of CuII salts with phenanthroline and oxalate (ox) or oxamate (oxm) gives [Cu(phen)(ox)(H2O)] · H2O or [Cu(phen)(oxm)(H2O)] · H2O complexes while direct treatment of CuII salts with oxalate or oxamate gives [NH4]2[Cu(ox)2] and [Cu(oxm)2(H2O)2] respectively. The X-ray structures of one example of each system, aquo-oxamato-phenanthroline-copper(II)-dihydrate and the polymeric ammonium-bis(aquo)-tetraoxalato-dicopper(II)-dihydrate, are reported.

Dimethylthiophosphoryl hydrazone ligands and their copper complexes: crystal structures and analysis of their solution complexation behaviour by electrospray mass spectrometry

Four new thiophosphoryl ligands containing NNPS or CNPS connectivities have been prepared and three of them characterised by single-crystal X-ray diffraction. The complexation of these ligands with salts of CuI, CuII, NiII and ZnII has been studied by electrospray mass spectrometry and uv-visible spectrophotometry in acetonitrile and methanol solution. Evidence for 1∶1 and 2∶1 complexation is presented. Two copper(I) complexes were isolated including a mixed chloride–bromide copper(I) complex in which a dimeric structure is adopted with a 22-membered metallacycle.

Solid State and Solution Characterization of Chiral, Conformationally Mobile Tripodal Ligands

The synthesis of the ligands N,N-bis[(2-pyridyl)methyl]-1-(2-pyridyl)ethanamine (1, α-MeTPA), N,N-bis[(6-phenyl-2-pyridyl)methyl]-1-(2-pyridyl)ethanamine (2, α-MePh2TPA), N,N-bis[(2-quinolyl)methyl]-1-(2-pyridyl)ethanamine, (3, α-MeBQPA), and N,N-bis[(2-pyridyl)]methyl(phenyl)(2-pyridyl)methanamine (4, α-PhTPA) is described. The ligands form chiral, pseudo C3-symmetric complexes with ZnII and CuII salts that possess an available electrophilic coordination site. X-ray crystallographic structures of the complexes [Zn(α-MeTPA)Cl](ClO4), [Zn(α-MeBQPA)Cl](ClO4), and [Zn(α-PhTPA)Cl](ClO4) show that the spatial arrangement of the three pyridyl groups resembles a propeller whose directional sense is controlled by a substituent on one methylene arm. Chiroptical measurements provide supporting information that the complexes maintain similar structures in solution. Monte Carlo/stochastic dynamics (MC/SD) simulations of the [Zn(L)Cl]+ complexes indicate that only two conformers are populated at normal temperatures, suggest the presence of a synchronicity in the movement of the heteroaromatic rings during conformer interconversions, and provide an estimate of the energy difference between the conformers.

A novel vicinal dioxime and its homo- and heterotrinuclear complexes

The new vicinal dioxime N,N′-bis(2-benzimidazolylmethyl)diaminoglyoxime (H2L) has been prepared by reacting 2-aminomethylbenzimidazole with cyanogen-di-N-oxide. Reaction of H2L with CuII and CoIII salts and appropriate reagents gave mono- and trinuclear complexes, [Cu(HL)2], [Cu3(L)2(phen)2], [Co(HL)2L′Cl] (L′=2,6-lutidine), [Co(LBF2)2L′′Cl] and [Cu2(ClO4)2Co(LBF2)2L′Cl](ClO4)2, which were characterized by i.r., 1H- and13 C-n.m.r., m.s. and elemental analyses.

Structure and Properties of Transition‐Metal Complexes with Chiral C2‐symmetric binucleating ligands

AbstractThe coordination behavior of chiral binucleating ligands of type 1–4 with various transition metals has been investigated. 1H‐NMR Titration experiments with zinc(II) salts gave detailed structural information about the structure of the resulting zinc complexes. Ligand 1 forms an unusual C3‐symmetric dinuclear zinc complex [Zn2CIL3] (8a) which was characterized by X‐ray crystallography. Treatment of complex 8a with various carboxylic acids resulted in ligand‐exchange reactions. With ligand 2, a hydroxo‐bridged dinuclear copper complex 15 was synthesized and its structure elucidated by X‐ray analysis. Solution studies UV and 1H‐NMR spectroscopy of the reaction of ligand 3 with ZnII and NII salts revealed the formation of dimeric species of the type [M2X4L2]. Ligand 4 formed well‐defined dinuclear complexes with NiII and CuII salts of which the corresponding NiII complex [Ni2(AcO)2(ClO4)2L] (22a) was characterized by crystal‐structure analysis.

Rapid Coupling of Methyl Iodide with Aryltributylstannanes Mediated by Palladium(0) Complexes: A General Protocol for the Synthesis of 11CH3‐Labeled PET Tracers

AbstractThe reaction of methyl iodide and (excess) aryltributylstannane to give a methylarene has been studied with the focus on the realization of rapid coupling for incorporation of short‐lived radionuclides into bioactive organic compounds. The coupling of methyl iodide with tributylphenylstannane (40 equiv) is accomplished in &gt;90% yield within 5 min at 60°C with a tri‐o‐tolylphosphine‐bound, coordinatively unsaturated Pd0 complex together with a CuI salt and K2CO3 in DMF. This protocol is applicable to a variety of homo‐ and heteroaromatic tin compounds, to give the corresponding methylated derivatives. The effects of the tri‐o‐tolylphosphine ligand, a Cu(I) salt, and DMF are discussed. This new protocol provides a firm chemical basis for the synthesis of 11CH3‐incorporated PET tracers.