17236-59-8Relevant articles and documents
β-Diketone boron difluoride dye-functionalized conjugated microporous polymers for efficient aerobic oxidative photocatalysis
Dong, Kaixun,Gong, Weitao,Hassan, Mehdi,Liu, Lu,Ning, Guiling
, p. 3905 - 3913 (2021/06/18)
Incorporation of organic chromophores into conjugated micro/mesoporous polymers (CMPs) provides a promising avenue for developing recyclable heterogeneous photocatalysts by overcoming tedious separation and low reusability of homogeneous organic dye-based photocatalysts. However, the design principle and the underlying structure-property relationship for fabricating and selecting various organic dye-embedded CMPs for efficient photocatalysis have not been well-constructed so far. In this study, we described the rational fabrication of two new CMPsviathe one-step Sonogashira coupling using β-diketone boron difluoride dye as the key linker and commonly used building blocks (triphenylamine/triphenylbenzene) as the cores. The resulting boron-dye containing CMPs were efficiently employed as the metal-free photocatalysts in two typical aerobic oxidative organic transformations including coupling of benzylamine and oxidation of aryl boronic acids to corresponding aryl phenols, which have never been explored with other boron-dye-embedded CMPs. They exhibited superior photocatalytic performance compared to their boron-free counterparts due to their wide visible-light absorption, narrow optical bandgaps, and extended π-conjugation due to boron-complexation. The present study establishes β-diketone boron difluoride dyes as efficient building blocks for fabricating new CMP-based photocatalysts.
Toward 2-Thiophyne: Ketocarbene versus Hetaryne Intermediates from 2-(Trimethylsilyl)thiophen-3-yl Triflate
Pozo, Iago,Cobas, Agustín,Pe?a, Diego,Guitián, Enrique,Pérez, Dolores
supporting information, p. 7376 - 7380 (2021/10/01)
The reaction of 2-(trimethylsilyl)thiophen-3-yl triflate with CsF in the presence of 2,3,4,5-tetraphenylcyclopentadienone affords 4,5,6,7-tetraphenylbenzo[b]thiophene, as it would be expected from the hypothesized generation and trapping of 2-thiophyne. H
An efficient base and H2O2 free protocol for the synthesis of phenols in water and oxygen using spinel CuFe2O4 magnetic nanoparticles
Chutia, Rituparna,Chetia, Bolin
, p. 1925 - 1936 (2020/08/13)
An efficient base and H2O2 free protocol was used for the synthesis of phenols from boronic acids using biogenic CuFe2O4 magnetic nanoparticles as catalyst at room temperature in water and oxygen. The catalyst was prepared using the flowers of Lantana camara. The size of the nanoparticles was 4.27 nm. Base free and ligand free protocol, less time, excellent yields, room temperature, biogenic synthesis of the catalyst, use of O2 as an environmentally friendly oxidant are the advantages of the present protocol. The recyclability of the catalyst was for 5 cycles without loss of magnetic property or catalytic activity.
Synthesis of 3-Benzo[b]thienyl 3-Thienyl Ether via an Addition-Elimination Reaction and Its Transformation to an Oxygen-Fused Dithiophene Skeleton: Synthesis and Properties of Benzodithienofuran and Its π-Extended Derivatives
Mitsudo, Koichi,Kurimoto, Yuji,Mandai, Hiroki,Suga, Seiji
supporting information, p. 2821 - 2824 (2017/06/07)
The synthesis of 3-benzo[b]thienyl 3-thienyl ether and its dehydrogenative cyclization leading to benzodithienofuran (BDTF; [1]benzothieno[3,2-b]thieno[2,3-d]furan) are described for the first time. Further transformation of BDTF to more π-extended BDTF d
Grafting of Ru(III) complex onto nanosilica and its implication as heterogeneous catalyst for aerobic oxidative hydroxylation of arylboronic acids
Gogoi, Nibedita,Gogoi, Pradip K.,Borah, Geetika,Bora, Utpal
, p. 4050 - 4052 (2016/08/18)
An ecofriendly and highly efficient protocol for aerobic oxidative hydroxylation of aryl and heteroaryl boronic acids catalyzed by Ru(III) imine complex immobilized on nanosilica, derived from rice husk, has been developed. The main significance of this protocol is the base free and aerobic reaction condition at room temperature, short reaction time, aqueous reaction medium, and excellent yield of the product. This heterogeneous catalyst is reusable up to sixth cycle without loss in activity.
o-directed lithiation of acylated hydroxythiophenes
Vendina, Ineta,Parkova, Anete,Trapencieris, Peteris
, p. 1565 - 1572 (2016/11/01)
O-Carbamates derived from 2-hydroxy- and 3-hydroxy-thiophenes generated o-directed carbanions, which were transformed to the corresponding methyl sulfides and methyl and trimethylsilyl substituted thiophenes.
Synthesis of dragmacidin D via direct C-H couplings
Mandal, Debashis,Yamaguchi, Atsushi D.,Yamaguchi, Junichiro,Itami, Kenichiro
supporting information; experimental part, p. 19660 - 19663 (2012/01/13)
Dragmacidin D, an emerging biologically active marine natural product, has attracted attention as a lead compound for treating Parkinson's and Alzheimer's diseases. Prominent structural features of this compound are the two indole-pyrazinone bonds and the presence of a polar aminoimidazole unit. We have established a concise total synthesis of dragmacidin D using direct C-H coupling reactions. Methodological developments include (i) Pd-catalyzed thiophene-indole C-H/C-I coupling, (ii) Pd-catalyzed indole-pyrazine N-oxide C-H/C-H coupling, and (iii) acid-catalyzed indole-pyrazinone C-H/C-H coupling. These regioselective catalytic C-H couplings enabled us to rapidly assemble simple building blocks to construct the core structure of dragmacidin D in a step-economical fashion.
Synthesis of 3-hydroxythiophenes and thiophen-3(2H)-ones by pyrolysis of alkylsulfanylmethylene Meldrum's acid derivatives
Hunter, Gordon A.,McNab, Hamish
, p. 1209 - 1214 (2007/10/02)
3-Hydroxythiophene 1 and a range of its 2-substituted, 2,2-disubstituted and 5-substituted derivatives have been made by flash vacuum pyrolysis (FVP) of an appropriate alkylsulfanylmethylene derivative of Meldrum's acid 3 or 4.These compounds are readily obtained, either by reaction of methoxymethylene Meldrum's acid with alkylthiols in refluxing acetonitrile, or via the bis(methylsulfanyl) compound 18 by known procedures.The pyrolysis proceeds by a hydrogen-transfer-cyclisation mechanism in which thereis extensive loss of configuration of a chiral centre at the reaction site.The NMR and mass spectra of the Meldrum's acid precursors and the mass spectra of the 3-hydroxythiophenes are briefly discussed.
Tautomerism of the Monohydroxy Derivatives of Five-Membered O, N, and S Heterocycles
Capon, Brian,Kwok, Fu-Chiu
, p. 5346 - 5356 (2007/10/02)
The O-deuterated enolic tautomers 3-deuteroxybenzofuran, 3-deuteroxybenzothiophene, 3-deuteroxyindole, 3-deuteroxy-1-methylindole, 3-deuteroxyfuran, 3-deuteroxythiophene, 2-deuteroxybenzothiophene, and 2-deuteroxythiophene have been generated in solution in mixtures of CD3COCD3, CD3CN, or CD3SOCD3 with D2O by hydrolysis of their trimethylsilyl derivatives in the presence of DCl (1E-3 - 1E-4 M) and characterized by 1H NMR spectroscopy.Solutions of 3-hydroxypyrrole and of 3-hydroxy-1-methylpyrrole were obtained by methanolysis of their trimethylsilyl derivatives,evaporation of the methanol, and immediate dissolution in DMSO-d6.The carbocyclic analogues of the bicyclic heterocyclic enols 3-deuteroxyindene and 2-deuteroxyindene were also generated in solution.Attempts to prepare solutions of 2-deuteroxyfuran, 2-deuteroxypyrrole, and 2-deuteroxy-1-methylpyrrole were unsuccessful.The kinetics of ketonization of the OH forms of these enols have been investigated in water or aqueous acetonitrile solution.The equilibrium constants for the keto-enol tautomerism were also determined either by direct measurement when sufficient enol was present at equilibrium or as the ratio of the rate constant for enolization of the keto form to that for ketonization of the enol form, the former being determined by the iodine-trapping technique.The effect of solvent on the equilibrium constants was also studied.Sufficient data were available for the equilibrium between 3-hydroxyindole and 3-ketoindole for them to be analyzed by the four-parameter equation of Mills and Beak to yield an a value of 2.4 and a b value of -3.0.The pKas of the bicyclic enols were measured. 3-Hydroxybenzofuran and3-hydroxybenzothiophene are stronger acids than 3-hydroxyindole and 3-hydroxy-1-methylindole.The ketonization reactions are general acid and general base catalyzed and their mechanisms are discussed.
Electrophilic Hydroxylation with Bis(trimethylsilyl)peroxide. A Synthon for the Hydroxyl Cation
Taddei, Maurizio,Ricci, Alfredo
, p. 633 - 635 (2007/10/02)
The regiospecific introduction of an hydroxy group in aromatic and aliphatic compounds can be performed in good yields by electrophilic hydroxylation of their organometallic derivatives with bis(trimethylsilyl)peroxide.
