Search results
Search for "aryl amines" in Full Text gives 8 result(s) in Beilstein Journal of Organic Chemistry.
5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines
- Ranjana Aggarwal and
- Suresh Kumar
Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15
- -arylaminopyrazolo[1,5-a]pyrimidines 143 by the coupling reaction of 7-chloropyrazolo[1,5-a]pyrimidines 140 with various aryl amines 141 in ethanol, which were evaluated for their anti-Plasmodium falciparum, antimalarial, and Pf-dihydroorotate dehydrogenase inhibitory activity (Scheme 40). 7-Arylaminopyrazolo[1,5-a
Graphical Abstract
Figure 1: Selected examples of drugs with fused pyrazole rings.
Figure 2: Typical structures of some fused pyrazoloazines from 5-aminopyrazoles.
Scheme 1: Regiospecific synthesis of 4 and 6-trifluoromethyl-1H-pyrazolo[3,4-b]pyridines.
Scheme 2: Synthesis of pyrazolo[3,4-b]pyridine-6-carboxylates.
Scheme 3: Synthesis of 1,4,6-triaryl-1H-pyrazolo[3,4-b]pyridines with ionic liquid .
Scheme 4: Synthesis of coumarin-based isomeric tetracyclic pyrazolo[3,4-b]pyridines.
Scheme 5: Synthesis of 6-substituted pyrazolo[3,4-b]pyridines under Heck conditions.
Scheme 6: Microwave-assisted palladium-catalyzed synthesis of pyrazolo[3,4-b]pyridines.
Scheme 7: Acid-catalyzed synthesis of pyrazolo[3,4-b]pyridines via enaminones.
Scheme 8: Synthesis of pyrazolo[3,4-b]pyridines via aza-Diels–Alder reaction.
Scheme 9: Synthesis of macrocyclane fused pyrazolo[3,4-b]pyridine derivatives.
Scheme 10: Three-component synthesis of 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine derivatives.
Scheme 11: Ultrasonicated synthesis of spiro[indoline-3,4'-pyrazolo[3,4-b]pyridine]-2,6'(1'H)-diones.
Scheme 12: Synthesis of spiro[indoline-3,4'-pyrazolo[3,4-b]pyridine] derivatives under conventional heating co...
Scheme 13: Nanoparticle-catalyzed synthesis of pyrazolo[3,4-b]pyridine-spiroindolinones.
Scheme 14: Microwave-assisted multicomponent synthesis of spiropyrazolo[3,4-b]pyridines.
Scheme 15: Unexpected synthesis of naphthoic acid-substituted pyrazolo[3,4-b]pyridines.
Scheme 16: Multicomponent synthesis of variously substituted pyrazolo[3,4-b]pyridine derivatives.
Scheme 17: Three-component synthesis of 4,7-dihydropyrazolo[3,4-b]pyridines and pyrazolo[3,4-b]pyridines.
Scheme 18: Synthesis of pyrazolo[3,4-b]pyridine-5-spirocycloalkanediones.
Scheme 19: Ultrasound-mediated three-component synthesis of pyrazolo[3,4-b]pyridines.
Scheme 20: Multicomponent synthesis of 4-aryl-3-methyl-1-phenyl-4,6,8,9-tetrahydropyrazolo [3,4-b]thiopyrano[4...
Scheme 21: Synthesis of 2,3-dihydrochromeno[4,3-d]pyrazolo[3,4-b]pyridine-1,6-diones.
Scheme 22: FeCl3-catalyzed synthesis of o-hydroxyphenylpyrazolo[3,4-b]pyridine derivatives.
Scheme 23: Ionic liquid-mediated synthesis of pyrazolo[3,4-b]pyridines.
Scheme 24: Microwave-assisted synthesis of pyrazolo[3,4-b]pyridines.
Scheme 25: Multicomponent synthesis of pyrazolo[3,4-b]pyridine-5-carbonitriles.
Scheme 26: Unusual domino synthesis of 4,7-dihydropyrazolo[3,4-b]pyridine-5-nitriles.
Scheme 27: Synthesis of 4,5,6,7-tetrahydro-4H-pyrazolo[3,4-b]pyridines under conventional heating and ultrasou...
Scheme 28: L-Proline-catalyzed synthesis of of pyrazolo[3,4-b]pyridine.
Scheme 29: Microwave-assisted synthesis of 5-aminoarylpyrazolo[3,4-b]pyridines.
Scheme 30: Microwave-assisted multi-component synthesis of pyrazolo[3,4-e]indolizines.
Scheme 31: Synthesis of fluoropropynyl and fluoroalkyl substituted pyrazolo[1,5-a]pyrimidine.
Scheme 32: Acid-catalyzed synthesis of pyrazolo[1,5-a]pyrimidine derivatives.
Scheme 33: Chemoselective and regiospecific synthesis of 2-(3-methylpyrazol-1’-yl)-5-methylpyrazolo[1,5-a]pyri...
Scheme 34: Regioselective synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines.
Scheme 35: Microwave-assisted synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidine carboxylates.
Scheme 36: Microwave and ultrasound-assisted synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines.
Scheme 37: Base-catalyzed unprecedented synthesis of pyrazolo[1,5-a]pyrimidines via C–C bond cleavage.
Scheme 38: Synthesis of aminobenzothiazole/piperazine linked pyrazolo[1,5-a]pyrimidines.
Scheme 39: Synthesis of aminoalkylpyrazolo[1,5-a]pyrimidine-7-amines.
Scheme 40: Synthesis of pyrazolo[1,5-a]pyrimidines from condensation of 5-aminopyrazole 126 and ethyl acetoace...
Scheme 41: Synthesis of 7-aminopyrazolo[1,5-a]pyrimidines.
Scheme 42: Unexpected synthesis of 7-aminopyrazolo[1,5-a]pyrimidines under solvent free and solvent-mediated c...
Scheme 43: Synthesis of N-(4-aminophenyl)-7-aryloxypyrazolo[1,5-a]pyrimidin-5-amines.
Scheme 44: Base-catalyzed synthesis of 5,7-diarylpyrazolo[1,5-a]pyrimidines.
Scheme 45: Synthesis of 6,7-dihydropyrazolo[1,5-a]pyrimidines in PEG-400.
Scheme 46: Synthesis of 7-heteroarylpyrazolo[1,5-a]pyrimidine-3-carboxamides.
Scheme 47: Synthesis of 7-heteroarylpyrazolo[1,5-a]pyrimidine derivatives under conventional heating and micro...
Scheme 48: Synthesis of N-aroylpyrazolo[1,5-a]pyrimidine-5-amines.
Scheme 49: Regioselective synthesis of ethyl pyrazolo[1,5-a]pyrimidine-7-carboxylate.
Scheme 50: Sodium methoxide-catalyzed synthesis of 3-cyano-6,7-diarylpyrazolo[1,5-a]pyrimidines.
Scheme 51: Synthesis of various pyrazolo[3,4-d]pyrimidine derivatives.
Scheme 52: Synthesis of hydrazinopyrazolo[3,4-d]pyrimidine derivatives.
Scheme 53: Synthesis of N-arylidinepyrazolo[3,4-d]pyrimidin-5-amines.
Scheme 54: Synthesis of pyrazolo[3,4-d]pyrimidinyl-4-amines.
Scheme 55: Iodine-catalyzed synthesis of pyrazolo[3,4-d]pyrimidinones.
Scheme 56: Synthesis of ethyl 6-amino-2H-pyrazolo[3,4-d]pyrimidine-4-carboxylate.
Scheme 57: Synthesis of 4-substituted-(3,6-dihydropyran-4-yl)-1H-pyrazolo[3,4-d]pyrimidines.
Scheme 58: Synthesis of 1-(2,4-dichlorophenyl)pyrazolo[3,4-d]pyrimidin-4-yl carboxamides.
Scheme 59: Synthesis of 5-(1,3,4-thidiazol-2-yl)pyrazolo[3,4-d]pyrimidine.
Scheme 60: One pot POCl3-catalyzed synthesis of 1-arylpyrazolo[3,4-d]pyrimidin-4-ones.
Scheme 61: Synthesis of 4-amino-N1,C3-dialkylpyrazolo[3,4-d]pyrimidines under Suzuki conditions.
Scheme 62: Microwave-assisted synthesis of pyrazolo[3,4-b]pyrazines.
Scheme 63: Synthesis and derivatization of pyrazolo[3,4-b]pyrazine-5-carbonitriles.
Scheme 64: Synthesis of 2-thioxo-pyrazolo[1,5-a][1,3,5]triazin-4-ones.
Scheme 65: Synthesis of 2,3-dihydropyrazolo[1,5-a][1,3,5]triazin-4(1H)-one.
Scheme 66: Synthesis of pyrazolo[1,5-a][1,3,5]triazine-8-carboxylic acid ethyl ester.
Scheme 67: Microwave-assisted synthesis of 4,7-dihetarylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 68: Alternative synthetic route to 4,7-diheteroarylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 69: Synthesis of 4-aryl-2-ethylthio-7-methylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 70: Microwave-assisted synthesis of 4-aminopyrazolo[1,5-a][1,3,5]triazine.
Scheme 71: Synthesis of pyrazolo[3,4-d][1,2,3]triazines from pyrazol-5-yl diazonium salts.
Scheme 72: Synthesis of 2,5-dihydropyrazolo[3,4-e][1,2,4]triazines.
Scheme 73: Synthesis of pyrazolo[5,1-c][1,2,4]triazines via diazopyrazolylenaminones.
Scheme 74: Synthesis of pyrazolo[5,1-c][1,2,4]triazines in presence of sodium acetate.
Scheme 75: Synthesis of various 7-diazopyrazolo[5,1-c][1,2,4]triazine derivatives.
Scheme 76: One pot synthesis of pyrazolo[5,1-c][1,2,4]triazines.
Scheme 77: Synthesis of 4-amino-3,7,8-trinitropyrazolo-[5,1-c][1,2,4]triazines.
Scheme 78: Synthesis of tricyclic pyrazolo[5,1-c][1,2,4]triazines by azocoupling reaction.
Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides
- Svetlana P. Panchenko,
- Alexei D. Averin,
- Maksim V. Anokhin,
- Olga A. Maloshitskaya and
- Irina P. Beletskaya
Beilstein J. Org. Chem. 2015, 11, 2297–2305, doi:10.3762/bjoc.11.250
- of diamines and spermine while the CuI/L-proline/EtCN system proved to be preferable for the diarylation of other tri- and tetraamines like spermidine, norspermidine and norspermine. Keywords: amination; aryl amines; aryl iodides; copper catalysis; polyamines; Introduction Natural diamines and
Graphical Abstract
Figure 1: Diamines and polyamines studied in Cu(I)-catalyzed amination reactions.
Scheme 1: N,N’-Diarylation of the diamines 1 and 2.
Scheme 2: Arylation of the diamines 1 and 2.
Scheme 3: Arylation of the diamines 3 and 4.
Scheme 4: Arylation of the diamines 1, 3, 4 with 2-fluoroiodobenzene.
Scheme 5: Arylation of the triamines 5 and 6.
Scheme 6: Arylation of the tetraamines 7 and 8.
Copper-mediated synthesis of N-alkenyl-α,β-unsaturated nitrones and their conversion to tri- and tetrasubstituted pyridines
- Dimitra Kontokosta,
- Daniel S. Mueller,
- Dong-Liang Mo,
- Wiktoria H. Pace,
- Rachel A. Simpson and
- Laura L. Anderson
Beilstein J. Org. Chem. 2015, 11, 2097–2104, doi:10.3762/bjoc.11.226
- . Keywords: Chan–Lam; copper; nitrone; oxygen transfer; pyridine; Introduction While most applications of the Chan–Lam reaction are focused on the synthesis of aryl ethers and aryl amines, our group has been interested in the use of the Chan–Lam reaction for the synthesis of O-alkenyl oximes and
Graphical Abstract
Scheme 1: Use of a Chan–Lam reaction for the synthesis of tetrahydroquinolines and potential extension to pyr...
Scheme 2: Examples of pyridine synthesis from oxime precursors [51,52].
Scheme 3: Solvent effect on conversion of N-alkenylnitrones to pyridines.
Scheme 4: Mechanistic experiments.
Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams
- Katherine M. Byrd
Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60
- Jørgensen group reported the first aza-Michael addition of secondary aryl amines [234]. The authors obtained the 1,4-addition products in moderate to high yields and enantioselectivities by using a nickel–DBFOX–Ph [235][236] catalyst (Scheme 30). Other chiral ligands have been used in addition to chiral
- 1,4-addition of aryl amines to N-alkenoyloxazolidinones [244]. In that report, they sometimes obtained a mixture of products, where one was the desired 1,4-addition product and the other product resulted from the 1,4-addition and acylation of the amine (Scheme 35). The side product was formed in
- higher amounts when electron-rich aryl amines were used. In the asymmetric variant of this reaction, Collin and co-workers discovered that reducing the temperature to −40 °C diminished, and in some cases, eliminated the formation of the undesired product (Scheme 36). Overall, this iodo(binaphtholato
Graphical Abstract
Scheme 1: Generic mechanism for the conjugate addition reaction.
Figure 1: Methods to activate unsaturated amide/lactam systems.
Scheme 2: DCA of Grignard reagents to an L-ephedrine derived chiral α,β–unsaturated amide.
Figure 2: Chiral auxiliaries used in DCA reactions.
Scheme 3: Comparison between auxiliary 5 and the Oppolzer auxiliary in a DCA reaction.
Scheme 4: Use of Evans auxiliary in a DCA reaction.
Figure 3: Lewis acid complex of the Evans auxiliary [43].
Scheme 5: DCA reactions of α,β-unsaturated amides utilizing (S,S)-(+)-pseudoephedrine and the OTBS-derivative...
Figure 4: Proposed model accounting for the diastereoselectivity observed in the 1,4-addition of Bn2NLi to α,...
Scheme 6: An example of a tandem conjugate addition–α-alkylation reaction of an α,β-unsaturated amide utilizi...
Scheme 7: Conjugate addition to an α,β-unsaturated bicyclic lactam leading to (+)-paroxetine and (+)-femoxeti...
Scheme 8: Intramolecular conjugate addition reaction to α,β-unsaturated amide.
Scheme 9: Conjugate addition to an α,β-unsaturated pyroglutamate derivative.
Scheme 10: Cu(I)–NHC-catalyzed asymmetric silylation of α,β-unsaturated lactams and amides.
Scheme 11: Asymmetric copper-catalyzed 1,4-borylation of an α,β-unsaturated amide.
Scheme 12: Asymmetric cross-coupling 49 to phenyl chloride.
Scheme 13: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated lactam.
Scheme 14: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated amide.
Scheme 15: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated amide using a chiral bicyclic dien...
Scheme 16: Synthesis of (R)-(−)-baclofen through a rhodium-catalyzed asymmetric 1,4-arylation of lactam 58.
Scheme 17: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated amide and lactam employing organo[...
Scheme 18: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated lactam employing benzofuran-2-ylzi...
Figure 5: Further chiral ligands that have been used in rhodium-catalyzed 1,4-additions of α,β-unsaturated am...
Scheme 19: Palladium-catalyzed asymmetric 1,4-arylation of arylsiloxanes to a α,β-unsaturated lactam.
Scheme 20: SmI2-mediated cyclization of α,β-unsaturated Weinreb amides.
Figure 6: Chiral Lewis acid complexes used in the Mukaiyama–Michael addition of α,β-unsaturated amides.
Scheme 21: Mukaiyama–Michael addition of thioester silylketene acetal to α,β-unsaturated N-alkenoyloxazolidino...
Scheme 22: Asymmetric 1,4-addition of aryl acetylides to α,β-unsaturated thioamides.
Scheme 23: Asymmetric 1,4-addition of alkyl acetylides to α,β-unsaturated thioamides.
Scheme 24: Asymmetric vinylogous conjugate additions of unsaturated butyrolactones to α,β-unsaturated thioamid...
Scheme 25: Gd-catalyzed asymmetric 1,4-cyanation of α,β-unsaturated N-acylpyrroles [205].
Scheme 26: Lewis acid-catalyzed asymmetric 1,4-cyanation of α,β-unsaturated N-acylpyrazole 107.
Scheme 27: Lewis acid mediated 1,4-addition of dibenzyl malonate to α,β-unsaturated N-acylpyrroles.
Scheme 28: Chiral Lewis acid mediated 1,4-radical addition to α,β-unsaturated N-acyloxazolidinone [224].
Scheme 29: Aza-Michael addition of O-benzylhydroxylamine to an α,β-unsaturated N-acylpyrazole.
Scheme 30: An example of the aza-Michael addition of secondary aryl amines to an α,β-unsaturated N-acyloxazoli...
Scheme 31: Aza-Michael additions of anilines to a α,β-unsaturated N-alkenoyloxazolidinone catalyzed by palladi...
Scheme 32: Aza-Michael additions of aniline to an α,β-unsaturated N-alkenoylbenzamide and N-alkenoylcarbamate ...
Scheme 33: Difference between aza-Michael addition ran using the standard protocol versus the slow addition pr...
Scheme 34: Aza-Michael additions of aryl amines salts to an α,β-unsaturated N-alkenoyloxazolidinone catalyzed ...
Scheme 35: Aza-Michael addition of N-alkenoyloxazolidiniones catalyzed by samarium diiodide [244].
Scheme 36: Asymmetric aza-Michael addition of p-anisidine to α,β-unsaturated N-alkenoyloxazolidinones catalyze...
Scheme 37: Asymmetric aza-Michael addition of O-benzylhydroxylamine to N-alkenoyloxazolidinones catalyzed by i...
Scheme 38: Asymmetric 1,4-addition of purine to an α,β-unsaturated N-alkenoylbenzamide catalyzed by (S,S)-(sal...
Scheme 39: Asymmetric 1,4-addition of phosphites to α,β-unsaturated N-acylpyrroles.
Scheme 40: Asymmetric 1,4-addition of phosphine oxides to α,β-unsaturated N-acylpyrroles.
Scheme 41: Tandem Michael-aldol reaction catalyzed by a hydrogen-bonding organocatalyst.
Scheme 42: Examples of the sulfa-Michael–aldol reaction employing α,β-unsaturated N-acylpyrazoles.
Scheme 43: Example of the sulfa-Michael addition of α,β-unsaturated N-alkenoyloxazolidinones.
Figure 7: Structure of cinchona alkaloid-based squaramide catalyst.
Scheme 44: Asymmetric intramolecular oxa-Michael addition of an α,β-unsaturated amide.
Scheme 45: Formal synthesis atorvastatin.
Micro-flow synthesis and structural analysis of sterically crowded diimine ligands with five aryl rings
- Shinichiro Fuse,
- Nobutake Tanabe,
- Akio Tannna,
- Yohei Konishi and
- Takashi Takahashi
Beilstein J. Org. Chem. 2013, 9, 2336–2343, doi:10.3762/bjoc.9.268
- employed reaction conditions, – in particular, the order of addition and the base selection [37] – and the symmetric ligands were obtained through the coupling of N-2,6-di(iPr)-phenylbenzimidochloride with aryl amines in the presence of Et3N in toluene [18][19]. Interestingly, in our case, only the
Graphical Abstract
Figure 1: Sterically crowded, and neutral chelating diimine ligands.
Scheme 1: One-step synthesis of the ligand 3b, and a plausible decomposition pathway for 3b to naphthylamine (...
Figure 2: Micro-flow synthesis of the ligands 3b and 3c.
Figure 3: ORTEP drawing of 3b. Thermal ellipsoids are set at 35% probability level. Hydrogen atoms are omitte...
Scheme 2: Synthesis of the ligand 3c through the coupling of 4 and 9.
Figure 4: ORTEP drawing of 3c. Thermal ellipsoids are set at 35% probability level. Hydrogen atoms are omitte...
Scheme 3: Complexation of the ligands 3b and 3c with NiBr2(dme).
Figure 5: ORTEP drawing of 12. Thermal ellipsoids are set at 35% probability level. Hydrogen atoms and cocrys...
Facile synthesis of functionalized tetrahydroquinolines via domino Povarov reactions of arylamines, methyl propiolate and aromatic aldehydes
- Jing Sun,
- Hong Gao,
- Qun Wu and
- Chao-Guo Yan
Beilstein J. Org. Chem. 2012, 8, 1839–1843, doi:10.3762/bjoc.8.211
- aryl amines could be used in the reaction to give more polysubstituted tetrahydroquinolines. Thus, after the addition reaction of one kind of arylamine with methyl propiolate had been completed, the aromatic aldehyde and the second arylamine were introduced to the reaction system. By using this method
Graphical Abstract
Scheme 1: Synthesis of polysubstituted tetrahydroquinolines 1a–1m.
Figure 1: Molecular structure of compound 1c.
Scheme 2: The proposed mechanism of domino Povarov reaction.
Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds
- Carolin Fischer and
- Burkhard Koenig
Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10
- hindered and functionalized aryl amines [22][23][24]. Aryl bromides are most frequently applied as substrates for the coupling of primary and cyclic secondary amines [17]. In the presence of a weak base such as caesium carbonate, many functional groups are tolerated, while NaOt-Bu has limitations when base
Graphical Abstract
Scheme 1: Synthesis of selective D3 receptor ligands.
Scheme 2: Synthesis of a novel 5-HT1B receptor antagonist.
Scheme 3: Synthesis of A-366833, a selective α4β2 neural nicotinic receptor agonist.
Scheme 4: A new route to oxcarbazepine.
Scheme 5: Synthesis of key intermediates for norepinephrine transporter (NET) inhibitors.
Scheme 6: N-Annulation yielding substituted indole for the synthesis of demethylasterriquinone A1.
Scheme 7: Palladium-catalysed double N-arylation contributing to the synthesis of murrazoline.
Scheme 8: Synthesis of vitamin E amines.
Scheme 9: Improved synthesis of martinellic acid.
Scheme 10: New tariquidar-derived ABCB1 inhibitors.
Scheme 11: β-Carbolin-1-ones as inhibitors of tumour cell proliferation.
Scheme 12: Copper-catalysed synthesis of promazine drugs.
Scheme 13: Palladium-catalysed multicomponent reaction for the synthesis of promazine drugs.
Scheme 14: Key intermediate for imatinib.
Scheme 15: Synthesis of an effective Chek1/KDR kinase inhibitor.
Scheme 16: Macrocyclization as final step of the synthesis of heat shock protein inhibitor.
Scheme 17: Synthesis of N-arylimidazoles.
Scheme 18: Synthesis of benzolactam V8.
Scheme 19: Synthesis of an intermediate for lotrafiban (SB-214857).
Scheme 20: Intermolecular effort towards lotrafiban.
Scheme 21: Synthesis of matrix metalloproteases (MMPs) inhibitor.
Scheme 22: Regioselective 9-N-arylation of purines.
Scheme 23: N-Arylation of adenine and cytosine.
Scheme 24: 9-N-Arylpurines as enterovirus inhibitors.
Scheme 25: Xanthine analogues as kinase inhibitors.
Scheme 26: Synthesis of dual PPARα/γ agonists.
Scheme 27: N-Aryltriazole ribonucleosides with anti-proliferative activity.
Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals
- Mohan Mahesh,
- John A. Murphy,
- Franck LeStrat and
- Hans Peter Wessel
Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1
- 1.5 equivalents of TDAE in anhydrous DMF yielded the indoles 51b–d in 63%, 43% and 64% yields (in three steps from the corresponding aryl amines 48b–d) respectively (Scheme 7). The indole 51d bearing a fused 9-membered ring was of particular interest to us because the important anticancer drugs
Graphical Abstract
Scheme 1: Aza- and thia-substituted electron donors.
Scheme 2: Radical-polar crossover reaction of arenediazonium salts by TTF.
Scheme 3: Studies on the reductive radical cyclization of arenediazonium salt 16 by TDAE.
Scheme 4: Preparation of the arenediazonium salts 31a–d. Reagents and conditions: (a) 23, NaH, THF, 0 °C, 0.5...
Scheme 5: Cascade radical cyclizations of arenediazonium salts 42 and 44 by TDAE. Reagents and conditions: (a...
Scheme 6: TDAE-mediated radical based addition-elimination route to indoles.
Scheme 7: Cyclization of the arenediazonium salts 49b–d by TDAE. Reagents and conditions: (a) NOBF4, CH2Cl2, ...
Scheme 8: Cyclization of the arenediazonium salt 62 by TDAE. Reagents and conditions: (a) 2-Nitrobenzenesulfo...
Scheme 9: Mechanism for the formation of the tetracyclic sulfonamide 65.
Scheme 10: Possible mechanism for the formation of indole (63) and indole sulfonamide 64.
