70487-21-7Relevant academic research and scientific papers
Visible Light-Induced, Metal-Free Denitrative [3+2] Cycloaddition for Trisubstituted Pyrrole Synthesis
Karki, Bhupal S.,Devi, Lalita,Pokhriyal, Ayushi,Kant, Ruchir,Rastogi, Namrata
supporting information, p. 4793 - 4797 (2019/11/16)
A metal-free, regioselective synthesis of trisubstituted pyrroles has been developed through a formal [3+2] cycloaddition reaction between 2H-azirines and nitroalkenes under visible light/photoredox-catalyzed conditions. The reaction proceeds through 2H-a
Synthesis of 2,2,5-Trisubstituted 2 H-Pyrroles and 2,3,5-Trisubstituted 1 H-Pyrroles by Ligand-Controlled Site-Selective Dearomative C2-Arylation and Direct C3-Arylation
Yamaguchi, Miyuki,Fujiwara, Sakiko,Manabe, Kei
, p. 6972 - 6977 (2019/09/03)
Palladium-catalyzed site-selective dearomative C2-arylation of 2,5-diaryl-1H-pyrroles with aryl chlorides was accomplished, and a series of 2,2,5-triaryl-2H-pyrroles were synthesized. In addition, the site selectivity of the reaction was switched by simply changing the ligand, and the direct C3-arylated 2,3,5-triaryl-1H-pyrroles were prepared. The obtained 2,2,5-triaryl-2H-pyrroles could be further transformed into 2,2,5,5-tetraarylpyrrolidines.
Iron-Catalyzed Radical Cycloaddition of 2H-Azirines and Enamides for the Synthesis of Pyrroles
Zhao, Mi-Na,Ren, Zhi-Hui,Yang, De-Suo,Guan, Zheng-Hui
supporting information, p. 1287 - 1290 (2018/03/09)
A novel and efficient Fe-catalyzed radical cycloaddition of 2H-azirines and enamides for the synthesis of substituted pyrroles has been developed. The radical cycloaddition reaction proceeded through a conceptually new Fe(II)-catalyzed homolytic cleavage of C-N bond of 2H-azirines sequential radical cyclization with enamides. The reaction used readily available starting materials, tolerated various functional groups, and afforded valuable triaryl-substituted pyrroles in good to high yields under mild reaction conditions.
Base-Promoted Oxidative Dearomatization of Pyrroles to 4-Pyrrolin-2-ones
Huang, Huabin,Hu, Bing,Lai, Yuanfa,Zou, Zhongai,Lin, Huixia,Xiao, Yujuan,You, Qihua,Shen, Jinhai
supporting information, p. 3906 - 3910 (2018/09/21)
A base-promoted oxidative dearomatization of substituted pyrroles for the synthesis of 3,3-disubstituted 4-pyrrolin-2-ones under mild reaction conditions is described. A cascade aerobic oxidation/semipinacol rearrangement reaction was involved, and the desired products bearing a quaternary carbon center were efficiently prepared using molecular oxygen (O2) as an ideal oxidant. (Figure presented.).
Selective ruthenium-catalyzed three-component synthesis of pyrroles
Zhang, Min,Neumann, Helfried,Beller, Matthias
supporting information, p. 597 - 601 (2013/02/23)
It's a snap: A novel catalytic three-component coupling reaction using simple and easily available substrates leads to a wide range of substituted pyrroles with high regioselectively (see scheme; Xantphos=9,9-dimethyl-4,5- bis(diphenylphosphino)xanthene). Copyright
One pot regiospecific synthesis of polysubstituted pyrroles from benzylamines and ynones under metal free conditions
Shen, Jinhai,Cheng, Guolin,Cui, Xiuling
supporting information, p. 10641 - 10643 (2013/11/06)
A convenient one-pot weak base-promoted synthesis of polysubstituted pyrroles has been developed from benzylamines and ynones. This transformation involves the Michael addition reaction and intramolecular condensation, which features high regioselectivity, high efficiency, environmental friendliness and metal free. A series of polysubstituted pyrroles were provided in up to 91% yield for 27 examples.
Organische Synthesen mit Uebergangsmetall-Komplexen XLV. 3-Hydroxypyridine, 1H-Pyrrole und 2-Hydroxypyrrol-Derivate aus einem Aminocarben-Chromkomplex und Alkinen
Aumann, Rudolf,Heinen, Heinrich
, p. C1 - C6 (2007/10/02)
Pyrroles VI, 3-hydroxypyridines V and 2-hydroxypyrroles IX have been obtained from (amino,phenylcarbene)pentacarbonyl-chromium (I) by simple two-step procedures.The first step involves the generation of 2-azaallenyl(pentacarbonyl)chromium complexes III, and VIII by condensation of I with an aldehyde II and an acid chloride VII, respectively.Complexes III react with alkynes IVa-i to give pyrroles VI and 3-hydroxypyridines V.VIII adds alkynes IVa,e,g to give 2-hydroxypyrroles IX.
The Diverse Carbenic and Cationic Chemistry of 3-Diazo-2,5-diphenylpyrrole
Nagarajan, M.,Shechter, H.
, p. 62 - 74 (2007/10/02)
3-Diazo-2,5-diphenylpyrrole (1) thermolyzes and photolyzes to 2,5-diphenyl-3H-pyrrolylidene (3), which inserts into methylene hydrogen of cyclohexane and methyne hydrogen of cumene.Hydrogen abstraction to give 2,5-diphenylpyrrole (7) occurs competitively in these systems.Carbene 3 reacts with cyclohexene, allylbenzene, and 2,3-dimethyl-2-butene to give 3-(allylically substituted)-2,5-diphenylpyrroles (15, 20, 21, and 29) as the only products of olefin incorporation along with 7.The initial position of the double bond in the olefin may be altered in the overall insertion process, and cyclopropanes are not isolable.The apparent behavior of 3 with saturated and olefinic hydrocarbons is as singlet 8s and triplet 9t.Reactions of 3 with anisole (31a) and with toluene (31b), benzenes substituted by electron-donor groups, result in selective ortho and/or para substitution to give 2,5-diphenyl-3-(substituted-phenyl)pyrroles (38a, 35, and 38b) and in hydrogen abstraction to 7.Insertion into the methyl groups and hydrogen abstraction also occur in reactions of 3 with 31b, yielding 3-benzyl-2,5-diphenylpyrrole (39) and 1,2-diphenylethane (40).Benzene (42a), however, reacts thermally or photolytically with 1 to form 1,3-diphenyl-2H-cyclooctapyrrole (46a), a member of a new heterocyclic system.Ring expansions to 4-, 5-, and 6-cyano-1,3-diphenyl-2H-cyclooctapyrroles (46b, 46b', and 46b'') and 4-, 5-, and 6-nitro-1,3-diphenyl-2H-cyclooctapyrroles (46c, 46c', and 46c'') are the principal reactions of 3 with benzonitrile (42b) and nitrobenzene (42c). 3-(m-Nitrophenyl)-2,5-diphenylpyrrole (47b) is also formed from 1 and 42c at 170 deg C.Thermolysis and photolysis of 1 to effect substitution and ringexpansion of benzenes may involve electrophilic attack of 8s to form spiropyrrolonorcaradienes (32).Directed heterolytic ring opening of 32 and (1,5 sigmatropic) rearrangements of hydrogen will rationalize the selective ortho and/or para substitution processes.Cyclooctapyrroles may arise from (electrocyclic) isomerization of 32 to spirocycloheptatrienes 44, (1,5 sigmatropic) rearrangement involving ring expansion to 45, and then hydrogen migration.Triplet photosensitization of 1 in 42a and 42b leads to 2,3,5-triphenylpyrrole (47a) and 3-(o-cyanophenyl)-2,5-diphenylpyrrole (47c), products of aromatic substitution rather than ring expansion.Such photolytic processes may involve generation and then addition of 9t to 42a and 42b, spin inversion of the triplet to singlet diradical intermediates, and successive hydrogen migrations.Aniline (59a), N-methylaniline (59b), and N,N-dimethylaniline are nucleophiles in that they are pyrrylated on nitrogen by 1 at 180 deg C.Primary and secondary alcohols and 1 undergo oxidation/reduction to carbonyls and 7; conversion to 3-alkoxy-2,5-diphenylpyrroles is minor except in the presence of ...
