1160-28-7Relevant articles and documents
Photochromic transformations in solutions of 8,8′-diquinolyl disulfide and di(mercaptoquinolinato)nickel(II)
Vorobyev,Plyusnin,Ivanov,Grivin,Larionov,Lemmetyinen
, p. 2364 - 2373 (2005)
The nature of intermediate species and their reactions were studied by laser pulse photolysis for a photochromic system consisting of 8,8′-diquinolyl disulfide (RSSR) and a planar NiII complex di(mercaptoquinolinato)nickel(II) (Ni(SR)2) in toluene and benzene solutions. Under exposure to laser radiation, disulfide RSSR dissociates to two RS? radicals, whose spectrum has an intense absorption band with a maximum at λ = 400 nm (ε = 8400 L mol-1 cm -1). The radicals disappear by recombination (2krec = 4.6 · 109 L mol-1 s-1). In the presence of the Ni(SR)2 complex, coordination of the radical (kcoord = 4.4 · 109 L mol-1 s-1) competes with recombination to form a radical complex RS?Ni(SR)2 having an intense absorption band with a maximum at 460 nm (ε = 16 600 L mol-1 cm-1). This species decays in the second-order reaction (2k = 4.6 · 104 L mol-1 s-1). Since the photochromic system returns to the initial state, the reaction of two radical complexes is assumed to produce radical recombination and reduction of the disulfide and Ni(SR)2 complex. Analysis of the kinetic data showed that some RS? radicals decay in the microsecond time interval due to the reaction with the RS?Ni(SR)2 radical complex (k = 3.1 · 109 L mol-1 s -1).
Synthesis of Symmetrical Thiosulfonates via Cu(OTf)2-Catalyzed Reductive Homocoupling of Arenesulfonyl Chlorides
Liu, Lixia,Luo, Bo,Wang, Chengming
supporting information, p. 5880 - 5883 (2021/11/27)
A variety of symmetrical thiosulfonates are synthesized via Cu-catalyzed reductive homocoupling of aryl sulfonyl chlorides. This protocol uses organic amine acting as a mild reductant and low-cost copper as an effective catalyst. Such a reductive coupling process features a broad substrate scope and good functional group tolerance. Related thiosulfonate products can also be converted into diverse functional molecules.
Hydrazo coupling: The efficient transition-metal-free C-H functionalization of 8-hydroxyquinoline and phenol through base catalysis
Solyev, Pavel N.,Sherman, Daria K.,Novikov, Roman A.,Levina, Eugenia A.,Kochetkov, Sergey N.
supporting information, p. 6381 - 6389 (2019/12/03)
Azodicarboxylate esters are common reagents in organic synthesis laboratories due to their utility in the Mitsunobu reaction. They can also be regarded as possible starting compounds for C-H functionalization, which up until now has been mainly achieved by transition-metal-catalyzed reactions. We have developed a novel reaction involving the quantitative coupling of 8-hydroxyquinoline or phenol with azodicarboxylate esters. The functionalization proceeds under mild base-catalyzed conditions selectively, and either the ortho-position of 8-hydroxyquinoline or para-position of the phenol/naphthol is involved in the reaction. This type of transformation can be considered as "hydrazo coupling" (by analogy with azo coupling). Herein, we discuss a plausible mechanism for this catalyzed substitution, backing up our findings with deuterium NMR experiments and by varying the starting compounds and bases. Using Boc-NN-Boc as a substrate, we have developed the convenient and efficient synthesis of (8-hydroxyquinolin-7-yl)hydrazines, as well as demonstrating a new stereoselective route for the synthesis of medicinally important 4-hydroxyphenylhydrazine for laboratory use, which almost doubles the yield of the common industrial process and reduces the number of synthetic steps. A new "one-pot" procedure for the synthesis of aromatic 8-hydroxyquinolin-7-yl hydrazones was applied.
