Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• milling CuAAC reaction pathway when using different catalysts. The electronic structure of Cu catalysts after the reaction completion was assayed by electron spin resonance (ESR) spectroscopy. All milling reactions, except the one using copper(0) as catalyst, were compared to solution procedures to

• -free click reactions. Electron spin resonance (ESR) spectroscopy ESR is an ideal technique for validating the oxidation and spin state of copper cations. Elemental copper and copper(I) are ESR silent, whereas the copper(II) shows strong and characteristic lines revealing local properties of this ion

• spin resonance (ESR) spectroscopy; in situ Raman monitoring; mechanochemistry; quinoline; solid-state click chemistry; Introduction The copper-catalyzed azide–alkyne cycloaddition (CuAAC) represents a prime example of click chemistry. Click chemistry describes “a set of near-perfect” reactions [1] for

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• , Japan 10.3762/bjoc.13.116 Abstract A detailed electron spin resonance (ESR) analysis of mechanically induced free radicals (mechanoradicals) formation of glucose-based polysaccharides, dextran (Dx) and glycogen (Gly) was performed in comparison with amylose mechanoradicals. The ESR spectra of the

• structure. Keywords: dextran; electron spin resonance (ESR); glycogen; mechanoradical; polysaccharide; Introduction There are many reports on the mechanolysis of synthetic and natural polymers. It is well-known that mechanically induced radicals, so-called mechanoradicals, are produced by the mechanolysis

• of a polymer at a temperature below its glass-transition temperature (Tg) due to the disruption of the polymer main chain [1]. Although most pulverization operations for a practical use are carried out at room temperature, electron spin resonance (ESR) spectroscopy analyses of mechanoradical

Thermodynamically stable [4 + 2] cycloadducts of lanthanum-encapsulated endohedral metallofullerenes

• Yuta Takano,
• Yuki Nagashima,
• M. Ángeles Herranz,
• Nazario Martín and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2014, 10, 714–721, doi:10.3762/bjoc.10.65

• peak attributed to the molecular ion peak (Figure 11). The electron spin resonance (ESR) spectrum of 5b showed a unique octet signal (see Supporting Information File 1), indicating the paramagnetic property of 5b as well as pristine La@C82. This result also indicates that the cycloaddition of the o

Stability of SG1 nitroxide towards unprotected sugar and lithium salts: a preamble to cellulose modification by nitroxide-mediated graft polymerization

• Guillaume Moreira,
• Laurence Charles,
• Mohamed Major,
• Florence Vacandio,
• Yohann Guillaneuf,
• Catherine Lefay and
• Didier Gigmes

Beilstein J. Org. Chem. 2013, 9, 1589–1600, doi:10.3762/bjoc.9.181

• the presence of unprotected glucose and lithium salts (LiBr and LiCl) in DMF or DMA by electron spin resonance (ESR). NMP of styrene was then performed with two SG1-based alkoxyamines (BlocBuilder MA alkoxyamine (BB)) and a cellobiose-BB alkoxyamine (called cello-SG1) with or without lithium salts

New core-pyrene π structure organophotocatalysts usable as highly efficient photoinitiators

• Sofia Telitel,
• Frédéric Dumur,
• Thomas Faury,
• Bernadette Graff,
• Mohamad-Ali Tehfe,
• Didier Gigmes,
• Jean-Pierre Fouassier and
• Jacques Lalevée

Beilstein J. Org. Chem. 2013, 9, 877–890, doi:10.3762/bjoc.9.101

• halide for FRP. The monomers investigated are given in Scheme 4. The mechanisms are analyzed by electron spin resonance (ESR), steady-state photolysis, fluorescence and laser flash photolysis (LFP). The ability of Co_Pys to behave as new organophotocatalysts is also discussed. Results and Discussion

Photoionisation of the tropyl radical

• Kathrin H. Fischer,
• Patrick Hemberger,
• Andras Bodi and
• Ingo Fischer

Beilstein J. Org. Chem. 2013, 9, 681–688, doi:10.3762/bjoc.9.77

• radical is expected to be Jahn–Teller (JT) distorted. The nature of this distortion and whether the equilibrium structure of tropyl corresponds to a distorted C2v or to D7h symmetry has been studied experimentally and theoretically. An early electron spin resonance (ESR) experiment found seven equivalent