4995-12-4Relevant academic research and scientific papers
Fabrication of Graphitic Carbon Nitride-Based Film: An Emerged Highly Efficient Catalyst for Direct C—H Arylation under Solar Light
Chaubey, Surabhi,Yadav, Rajesh K.,Kim, Tae Wu,Yadav, Tara Chand,Kumar, Abhishek,Dwivedi,Pandey,Singh, Atul P.
, p. 633 - 639 (2021/02/12)
Photoredox C—H bond formation can proceed in aerobic environment under solar light and has therefore become attractive. Nowadays, different types of expensive novel metal complexes and nanomaterials have been urbanized as photocatalysts for direct C—H bon
Pd-catalyzed C–H bond activation of Indoles for Suzuki reaction
Banerjee, Isita,Ghosh, Keshab Ch,Sinha, Surajit
, (2019/08/22)
Abstract: We present a practical method for Suzuki coupling by which unprotected or N-protected indoles may be selectively arylated in the C2-position through direct C–H bond activation by electrophilic Pd(TFA) 2 catalyst. The protocol is operationally simple as it is carried out in dioxane/water mixture, and air as the sole oxidant at room temperature. Various 2-arylated indoles were obtained in good yields. The protocol works for benzofuran, pyrrole and thiophene also. Graphic abstract: Selective C-2 arylation of heterocycles using Pd(II) catalyst via C–H activation was performed under ambient condition. C3–C2 migration of organopalladium intermediate controls the reaction pathway.[Figure not available: see fulltext.].
Isomer-Specific Hydrogen Bonding as a Design Principle for Bidirectionally Quantitative and Redshifted Hemithioindigo Photoswitches
Zweig, Joshua E.,Newhouse, Timothy R.
supporting information, p. 10956 - 10959 (2017/08/21)
A new class of bidirectionally quantitative photoswitches based on the hemithioindigo (HTI) scaffold is reported. Incorporation of a pyrrole hydrogen-bond donor leads to a bathochromic shift allowing for quantitative bidirectional isomerization. Additionally, extending conjugation from the electron-rich pyrrole results in quantitative visible-light photoswitches, as well as photoswitches that isomerize with red and near-infrared light. The presence of the hydrogen bond leading to the observed redshift is supported by computational and spectroscopic evidence.
Substituted pyrrole synthesis from nitrodienes
Karimi, Sasan,Ma, Shuai,Liu, Yanan,Ramig, Keith,Greer, Edyta M.,Kwon, Kitae,Berkowitz, William F.,Subramaniam, Gopal
, p. 2223 - 2227 (2017/05/16)
Though the Cadogan-Sundberg approach has been employed to synthesize a variety of indole and carbazole derivatives from nitroarenes, surprisingly, very little is reported for making pyrroles using the same approach from non-arene nitrodienes. Herein, we report a general method to synthesize substituted pyrroles, in one step with modest yields, from nitrodienes using triphenylphosphine in the presence of an Mo catalyst, bis(acetylaceto)dioxomolybdenum (VI). To shed light on the mechanism of this reaction, we performed DFT calculations using uB3LYP/6-31+G(d) basis set and observed that the reaction favors a path through a nitrene intermediate.
Synthesis of 2-arylpyrroles via catalytic dehydrogenation of 2-aryl-1-pyrrolines in the presence of palladium-supported on alumina
Figueira, Cláudia A.,Lopes, Patrícia S.,Gomes, Pedro T.
, p. 4362 - 4371 (2015/06/08)
A convenient synthesis of 2-arylpyrroles from the catalytic dehydrogenation of 2-aryl-1-pyrrolines in the presence of commercial palladium-supported on alumina (Pd/Al2O3) is described. The reaction scope was tested for aryl substituents with different steric hindrances and electronic natures. The dehydrogenation reaction conditions such as temperature, reflux time and amount of catalyst, revealed to be highly dependent on the 2-aryl substituent group, moderate to high yields and selectivities being obtained in a reaction involving straightforward work-up and purification procedures. In addition, the synthesis of the corresponding 2-aryl-1-pyrroline starting materials, through the cyclisation reaction involving 4-chlorobutyronitrile and aryl Grignard reagents, is also reported.
Expedient one-pot synthesis of pyrroles from ketones, hydroxylamine, and 1,2-dichloroethane
Trofimov, Boris A.,Mikhaleva, Al'Bina I.,Ivanov, Andrei V.,Shcherbakova, Viktoria S.,Ushakov, Igor A.
, p. 124 - 128 (2015/02/02)
2- and 2,3-Substituted pyrroles are readily synthesized in a one-pot procedure from ketones, hydroxylamine hydrochloride, and 1,2-dichloroethane in the KOH/DMSO system (120 °C, 2-4 h), the yields of pyrroles ranging 11-85%. Aliphatic, cycloaliphatic, aromatic, and heteroaromatic ketones tolerate the reaction conditions.
Direct synthesis of aryl substituted pyrroles from calcium carbide: An underestimated chemical feedstock?
Kaewchangwat, Narongpol,Sukato, Rangsarit,Vchirawongkwin, Viwat,Vilaivan, Tirayut,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
, p. 460 - 465 (2018/04/16)
In this work, a novel synthetic methodology for the preparation of aryl pyrroles directly from the reaction of calcium carbide with oxime is reported. Various pyrrole derivatives are generated from the corresponding oximes in satisfactory yields (49–88%) under the optimized conditions. The one-pot synthesis of aryl pyrrole from widely available ketone is also successfully developed. A new near-infrared fluorescent BODIPY dye containing a phenyl substitution at the C-3 position is expediently prepared from the aryl pyrrole derived from this methodology. The key benefit of this methodology is the use of an inexpensive and less hazardous primary chemical feedstock, calcium carbide, in a wet solvent without any metal catalysts. This process offers a novel cost-efficient route for the synthesis of functionalized pyrrole.
Original design of fluorescent ligands by fusing BODIPY and melatonin neurohormone
Thireau, Jeremy,Marteaux, Justine,Delagrange, Philippe,Lefoulon, Francois,Dufourny, Laurence,Guillaumet, Gerald,Suzenet, Franck
supporting information, p. 158 - 161 (2014/03/21)
An original design and synthesis of fluorescent ligands for melatonin receptor studies is presented and consists in the fusion of the endogenous ligand with the fluorescent BODIPY core. Probes I-IV show high affinities for MT1 and MT2 melatonin receptors and exhibit fluorescence properties compatible with cell observation.
Copper-catalyzed 5-endo-trig cyclization of ketoxime carboxylates: A facile synthesis of 2-arylpyrroles
Du, Wei,Zhao, Mi-Na,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
, p. 7437 - 7439 (2014/07/07)
A novel and facile copper-catalyzed 5-endo-trig cyclization of ketoxime carboxylates for the synthesis of 2-arylpyrroles has been developed. The reaction tolerates a range of functional groups and is a practical procedure for rapid synthesis of 2-arylpyrroles in high yields under mild conditions. the Partner Organisations 2014.
Synthesis and optical properties of difluorobora-s-diazaindacene dyes with trifluoromethyl meso-substituents
Sobenina, Lyubov N.,Petrova, Olga V.,Petrushenko, Konstantin B.,Ushakov, Igor A.,Mikhaleva, Albina I.,Meallet-Renault, Rachel,Trofimov, Boris A.
, p. 4107 - 4118 (2013/07/19)
A series of meso-CF3-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes with aryl and hetaryl substituents at the C-3 and C-5 positions, both symmetric and asymmetric, have been synthesized in 36-90 % yields by a new strategy involving as the key step the condensation of 2,2,2-trifluoro-1-(5- arylpyrrol-2-yl)-1-ethanols with diverse 2-arylpyrroles. The starting 2,2,2-trifluoro-1-(5-arylpyrrol-2-yl)-1-ethanols are easily prepared by reduction of the available 2-trifluoroacetyl-5-arylpyrroles. The synthesized dyes fluoresce in a longer wavelength region (626-698 nm) with high quantum yield (0.84-0.99). A new strategy for the synthesis of highly efficient symmetric and asymmetric BODIPY fluorophores that combine trifluoromethyl and 3,5-aryl substituents has been developed. The key step is the P 2O5-promoted condensation of 2,2,2-trifluoro-1-(5- arylpyrrol-2-yl)-1-ethanols with diverse 2-arylpyrroles. Copyright
