Center for Magnetic Resonance

M.Ya. Goikhmana, N.P. Yevlampieva, I.V. Podeshvo, S.A. Mil’tsov, V.S. Karavan, I.V. Gofman, A.P. Khurchak, A.V. Yakimansky

“Polymers with Cyanine Chromophore Groups in the Main Chain: Synthesis and Properties”

Polymer Science B, 2014, 56, 352-359

DOI:10.1134/S1560090414030051

Polyamides containing fragments of two cyanine chromophores in the main chain are synthesized, and their viscometric and electro-optical properties in solutions, as well as their stress-strain properties in films, are investigated. It is shown that the molecular characteristics of the copolyamides are substantially affected by chromophore fragments at a content of 10 mol %, while the mechanical properties of the films are independent of the chemical structures of chromophores incorporated into polyamide chains

A.S. Smirnov, E.S. Butukhanova, N.A. Bokach, G.L. Starova, V.V. Gurzhiy, M.L. Kuznetsov, V.Yu. Kukushkin

“Novel (cyanamide)ZnII complexes and zinc(II)-mediated hydration of the cyanamide ligands”

Dalton Trans, 2014, 43, 15798-15811

DOI:10.1039/c4dt01812e

The cyanamides NCNR₂ (R₂ = Me₂, Ph₂, C₅H₁₀) react with ZnX₂ (X = Cl, Br, I) in a 2[thin space (1/6-em)]:[thin space (1/6-em)]1 molar ratio at RT, giving a family of zinc(II) complexes [ZnX2(NCNR2)2] (R2 = Me2, X = Cl 1, X = Br 2, X = I 3; R2 = C5H10, X = Cl 4, X = Br 5; X = I 6; R2 = Ph2, X = Cl 7, X = Br 8, X = I 9; 75–92% yields). Complexes 7 and 8 undergo ligand redistribution in wet CH₂Cl₂ solutions giving the [Zn(NCNPh₂)4(H₂O)₂][Zn₂(μ-X)₂X₄] (X = Cl 10, Br 11) species that were characterized by 1H NMR, HRESI-MS, and X-ray diffraction. Halide abstraction from 1–3 by the action of AgCF₃SO₃ or treatment of Zn(CF₃SO₃)₂ with NCNR₂ (R₂ = Me₂, C₅H₁₀) leads to labile complexes [Zn(CF₃SO₃)₂(NCNR₂)₃] (R₂ = Me₂, 12; C₅H₁₀, 13). Crystallization of 12 from wet CH₂Cl₂ or from the reaction mixture gave [Zn(NCNMe₂)₃(H₂O)₂](SO₃CF₃)₂ (12a) or [Zn(CF₃SO₃)₂(NCNMe₂)₂]∞ (12b), whose structures were determined by X-ray diffraction. The ZnII-mediated hydration was observed for the systems comprising ZnX₂ (X = Cl, Br, I), 2 equiv. NCNR2 (R₂ = Me₂, C₅H₁₀, Ph₂) and ca. 40-fold excess of water and conducted in acetone at 60 °C (R₂ = Me₂, C₅H₁₀) or 80 °C (R₂ = Ph₂) in closed vials, and it gives the urea complexes [ZnX₂{OC(NR₂)NH₂}] (R₂ = Me₂, X = Cl 13, X = Br 14, X = I 15; R = C₅H₁₀, X = Cl 16, X = Br 17; X = I 18; R₂ = Ph₂, X = Cl 19, X = Br 20, X = I 21; 57–81%). In contrast to the ZnII-mediated hydration of conventional nitriles, which proceeds only in the presence of co-catalyzing oximes or carboxamides, the reaction with cyanamides does not require any co-catalyst. Complexes 1–9, 12–19 were characterized by 1H, 13C{1H} NMR, IR, HRESI-MS, and X-ray crystallography (for 1–3, 8, 9, 13–15, and 17), whereas 20 and 21 were characterized by HRESI+-MS and 1H and 13C{1H} NMR (for 20). The structural features of the cyanamide complexes 1, 2, 7, and 8 were interpreted by theoretical calculations at the DFT level.

E.A. Valishina, M.F.C. Guedes da Silva, M.A. Kinzhalov, S.A. Timofeeva, T.M. Buslaeva, M. Haukka, A.J.L. Pombeiro, V.P. Boyarskiy, V.Yu. Kukushkin, K.V. Luzyanin

“Palladium-ADC complexes as efficient catalysts in copper-free and room temperature Sonogashira coupling”

J. Molec. Catalysis , 2014, 395, 162-171

DOI:10.1016/j.molcata.2014.08.018

The metal-mediated coupling between cis-[PdCl₂(CNR¹)₂] [R¹ = cyclohexyl (Cy) 1, t-Bu 2, 2,6-Me₂C₆H₃ (Xyl) 3, 2-Cl-6-MeC₆H₃ 4] and hydrazones H₂NN=CR²R³ [R², R³ = Ph 5; R², R³ = C₆H₄(OMe-4) 6; R²/R³ = 9-fluorenyl 7; R² = H, R³ = C6H4(OH-2) 8] provided carbene complexes cis-[PdCl₂{C(N(H)N=CR²R³)=N(H)R¹}(CNR¹)] (9–24) in good (80–85%) yields. Complexes 9–24 showed high activity [yields up to 99%, and turnover numbers (TONs) up to 3.7 × 10⁴] in the Sonogashira coupling of various aryl iodides with a range of substituted aromatic alkynes without the need of copper co-catalyst. The catalytic procedure runs at 80 °C for 1 h in EtOH using K₂CO₃ as a base. No formation of homocoupling or acetylene decomposition products was observed. Designed copper-free Sonogashira system can also run at room temperature giving target products with yields up to 87% and TONs up to 87.

I.I. Eliseev, P.V. Gushchin, Yi.-A. Chen, P.-T. Chou, M. Haukka, G.L. Starova, V.Yu. Kukushkin

“Phosphorescent Pt(II) Systems Featuring Both 2,2’-Dipyridylamine and 1,3,5-Triazapentadiene Ligands”

Eur. J. Inorg. Chem. 2014 , 4101-4108

DOI:10.1002/ejic.201402364

The treatment of cis-[Pt(dpa)(RCN)₂][SO₃CF₃]₂ {dpa = 2,2′-dipyridylamine, R = Me, Et, CH₂Ph, Ph; [2a–d](OTf)₂} (OTf = SO₃CF₃) with 2 equiv. of N,N′-diphenylguanidine [NH=C(NHPh)₂] in CH₂Cl₂ solutions at room temp. for 16 h gives [Pt(dpa){NH=C(R)NC(NHPh)=NPh}][SO₃CF₃] {[3a,b,d](OTf)} as the addition products and [Pt(dpa){NH=C(R)NHC(R)=NH}][SO₃CF₃]₂ {[4a,b](OTf)₂} as the tailoring products. The formulation of complexes [3a,b,d](OTf) and [4a,b](OTf)₂ was supported by satisfactory C, H, and N elemental analyses and agreeable high-resolution ESI-MS, IR, and ¹H (including ¹H–¹H COSY experiments) and ¹³C{¹H} NMR data. The structures of all of the platinum species were determined by single-crystal X-ray diffraction. The resultant complexes are nonemissive in solution, mainly because of the interaction between the empty d_z² orbital in a square-planar configuration and solvent molecules. However, in the solid state, complexes [3a,b,d](OTf) exhibit strong phosphorescence with quantum yields (peak wavelength) of 0.23 (490 nm), 0.27 (483 nm), and 0.20 (532 nm), respectively.

O.Yu. Bakulina, A.Yu. Ivanov, D.V. Dar’in, P.S. Lobanov

“New transformations of 2-methylsulfanyl-4,6-dichloropyrimidine-5-carbaldehyde involving enamines: synthesis of condensed azines”

Mendeleev Commun 2014, 24, 163-164

DOI: 10.1016/j.mencom.2014.04.013

The reaction between 4,6-dichloropyrimidine-5-carbaldehyde and methyl 3-aminocrotonate leads to pyrido[2,3-d]pyrimidine which reacts with ethyl 3,3-diaminoacrylate to give pyrimido[4,5,6-de][1,6]naphthyridine derivative. The structure of the latter was confirmed by XRD analysis.

D.S. Ryabukhin, L.Yu. Gurskaya, G.K. Fukin, A.V. Vasilyev

“Superelectrophilic activation of N-aryl amides of 3-arylpropynoic acids: synthesis of quinolin-2(1H)-one derivatives”

Tetrahedron Lett., 2014, 70, 6428-6443

DOI: 0.1016/j.tet.2014.07.028

The superelectrophilic activation of N-aryl amides of 3-arylpropynoic acids by Bronsted superacids (CF3SO3H, HSO3F) or strong Lewis acids AlX3 (XјCl, Br) results in the formation of 4-aryl quinolin-2(1H)-ones in quantitative yields. The vinyl triflates or vinyl chlorides may be formed as additional reaction products. The investigated amides in reactions with benzene give 4,4-diaryl 3,4-dihydroquinolin-2-(1H)-ones under the superelectrophilic activation. 4-Aryl quinolin-2(1H)-ones in POCl3 are converted into 4-aryl 2-chloroquinolines. 4-Fluorophenyl-4-phenyl 3,4-dihydroquinolin-2-(1H)-one give N-formylation products in a yield of 79% under the VilsmeiereHaack reaction conditions.

A.V. Stepakov, V.M. Boitsov, A.G. Larina, A.P. Molchanov

”Acid-induced rearrangement of cycloadducts from N-aryl itaconimides and 1,3-diphenylisobenzofuran”

Tetrahedron Lett., 2014, accepted

DOI: 10.1016/j.tetlet.2014.06.107

Treatment of several Diels–Alder adducts of N-aryl itaconimides and 1,3-diphenylisobenzofuran with a strong acid triggers a skeletal rearrangement resulting in 2-aryl-6,10b-diphenylbenzo[h]isoquinoline-1,3(2H,10bH)-diones.