Reaction Of Aryl Azides Research Articles

A Facile, Efficient Step-Wise and Alternative Synthesis of Indolyl Triazoles via “Click” Chemistry

series of new 1,2,3 triazoles hybrids were synthesized using a Cu-catalysed azide-alkyne cycloaddition reaction. Thus, a remarkable rapid click reaction of aryl azides with terminal alkynes at room temperature in DMF afforded new 4-((1-((1-(4-methoxy-3-nitrophenyl)-1H-1,2,3-triazol-4- yl)methyl)-1H-indol-3-yl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-ones in good to excellent yields. The reaction provides a safe, efficient and economic approach for the synthesis of various 1,2,3 triazoles. The reaction has many advantages like shorter reaction times, good yields of products and isolation of the products without the need for column chromatography. By using knoevenagel reaction under physical grinding with alkylating agents prepared various 1,2,3 triazoles.

New cascade reaction of azides with malononitrile dimer to polyfunctional [1,2,3]triazolo[4,5-b]pyridine

ABSTRACTA new cascade reaction of azides with malononitrile dimer yielding polyfunctional [1,2,3]triazolo[4,5-b]pyridine was found. It was established that during the reaction of aryl azides with malononitrile dimer, under base catalysis, the formed intermediate triazole underwent spontaneous cyclization leading to the pyridine ring annulation. The obtained products have provided a new entry to [1,2,3]triazolo[4,5-b]pyridine.

ChemInform Abstract: Metal‐Free Synthesis of 1,2,3‐Triazoles by Azide—Aldehyde Cycloaddition under Ultrasonic Irradiation in TSIL [DBU‐Bu]OH and in Hydrated IL Bu4NOH under Heating.

Efficient and environmentally benign procedures have been reported for the synthesis of 1,4-disubstituted 1,2,3-triazoles by reaction of aryl azides with aldehydes in task-specific basic ionic liquid [DBU-Bu]OH under ultrasonic irradiation and in hydrated ionic liquid tetrabutylammonium hydroxide (Bu4NOH) under conventional heating. These protocols represent simple, general, and efficient approaches in terms of good yields, operational simplicity, easy workup, and shorter reaction time for the synthesis of 1,4-disubstituted 1,2,3-triazoles under metal-free conditions.

Metal-free synthesis of 1,2,3-triazoles by azide–aldehyde cycloaddition under ultrasonic irradiation in TSIL [DBU-Bu]OH and in hydrated IL Bu4NOH under heating

Efficient and environmentally benign procedures have been reported for the synthesis of 1,4-disubstituted 1,2,3-triazoles by reaction of aryl azides with aldehydes in task-specific basic ionic liquid [DBU-Bu]OH under ultrasonic irradiation and in hydrated ionic liquid tetrabutylammonium hydroxide (Bu4NOH) under conventional heating. These protocols represent simple, general, and efficient approaches in terms of good yields, operational simplicity, easy workup, and shorter reaction time for the synthesis of 1,4-disubstituted 1,2,3-triazoles under metal-free conditions.

Synthesis of 1-Aryl-5-Nitrobenzotriazoles*

3-Aryl-1-(3-nitrophenyl)triazenes were obtained in the cyclization reaction of diazotized 3-nitroaniline with arylamines in the presence of dimethyl sulfoxide and potassium carbonate to give 1-aryl- 5-nitrobenzotriazoles. Triazoles are commonly used intermediates in organic synthesis and have found application in industry, agriculture, and medicine (1). Many triazoles and their derivatives have high biological activity, including antitumor activity (2, 3). The synthesis of 1,2,3-benzotriazoles has been accomplished by various methods including diazotization of o-diaminoarenes, reaction of aryl azides with unsaturated compounds, and heterocyclization of o-amino-N-nitrosoarylamines or arylazobenzenes containing amino, nitro, or azido groups in the ortho position (4). The solid-phase synthesis of N-substituted 1H-benzotriazoles from ortho-halo- and ortho-nitroaryltriazenes has been described by Zimmermann and Brase (5). In the previous work (6), we developed a synthesis for triazoles using 9,10-anthraquinone derivatives. 3-Arylanthra(1,2-d)triazole-6,11-diones were obtained by the intramolecular heterocyclization of 1-aryl- 3-anthraquinonyltriazenes entailing intramolecular nucleophilic substitution of hydrogen in the presence of a basic catalyst. In the present work, we have studied the feasibility of forming the triazole ring using 1,3-diaryl- triazenes. We synthesized a series of 1,3-diaryltriazenes 1a-d containing a nitro group at position 3 in one of the aryl residues. The synthesis of diaryltriazenes was carried out by the diazotization of 3-nitroaniline and subsequent reaction of the resultant diazonium salt with a corresponding primary arylamine in pyridine. The composition and structure of the obtained diaryltriazenes were confirmed by physicochemical methods. The 1 H NMR spectra of diaryltriazenes 1b,c show a doubling of the signals both for the triazene and methyl group protons, indicating the existence of diphenyltriazenes containing an electron-withdrawing substituent and an electron-donor substituent in two tautomeric forms. The spectra of diaryltriazenes 1a,d, which combine a strong electron-withdrawing substituent and a weaker electron-withdrawing substituent, show

Efficient, green and regioselective synthesis of 1,4,5-trisubstituted-1,2,3-triazoles in ionic liquid [bmim]BF4 and in task-specific basic ionic liquid [bmim]OH

Convenient and environmentally benign procedures have been reported for the synthesis of 1,4,5-trisubstituted-1,2,3-triazoles by the reaction of aryl azides with active methylene compounds in ionic liquid [bmim]BF4 in the presence of l-proline as a catalyst and also in task-specific basic ionic liquid [bmim]OH. The methodologies defined herein avoid the severe conditions as posed by earlier existing methods and proved to be efficient in terms of good yields, operational simplicity, easy workup and short reaction time.

Synthesis of Triazoles via Regioselective Reactions of Aryl Azides with ­Cyanoacetyl Pyrroles and Indoles

Novel 5-aminotriazoles are prepared by the cycloaddition reactions of aryl azides with cyanoacetyl pyrroles and indoles. The regioselectivity of these reactions is discussed.

Reaction of aryl azides with tris(trimethylsilyl)silyllithium: Synthesis of tmeda or thf adducts of [Li{N(Ar)Si(SiMe 3) 3}] and 1,4-trimethylsilyl migration from oxygen to nitrogen

Reaction of ArN 3 (Ar = Ph, p-MeC 6H 4, 1-naphthyl) with [Li{Si(SiMe 3) 3}(thf) 3] yielded lithium amides [Li{N(Ar)Si(SiMe 3) 3}L] (L = tmeda or (thf) 2). Similar treatment of o-phenylene diazide with 2 equiv. of [Li{Si(SiMe 3) 3}(thf) 3] formed dilithium diamide complex 4. Reaction between o-Me 3SiOC 6H 4N 3 and [Li{Si(SiMe 3) 3}(thf) 3] afforded, via 1,4-trimethylsilyl migration from oxygen to nitrogen, [Li{OC 6H 4{N(SiMe 3)Si(SiMe 3) 3}-2}] 2 ( 5). The structures of complexes 3 and 5 have been determined by single crystal X-ray diffraction techniques.

FeCl3—NaI Mediated Reactions of Aryl Azides with 3,4‐Dihydro‐2H‐pyran: A Convenient Synthesis of Pyranoquinolines.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The synthesis, reactivity and magnetic susceptibilities of Cr(IV)porphyrin imido complexes, CrN(R), and attempts to form heterobinuclear μ-imido compounds with CrN(R)V and CrN(R)Fe bridges

The reactions of arylazides with chromium(II) porphyrin compounds lead to the production of paramagnetic ( d 2) imides, Cr IV(Por)N(R). The complexes undergo reaction with PPh 3, benzaldehyde, CS 2, CH 3I and styrene leading to transfer of the imido group. Reaction of Cr(Por)N(R) compounds with V IVO(acac) 2 and iron(II) salicylaldimines results in the formation of imido-bridged Cr IIIN(R)V(V) and Cr IIIN(R)Fe(III) species, as indicated by magnetic susceptibility vs temperature measurements down to 4.3 K.

Synthesis and reactivity of 4-acyl-5-hydroxytriazolines resulting from thermal reaction of aryl and tosyl azides with 2-substituted indane-1,3-diones

Reaction of aryl azides 1 with 2-methylindane-1,3-dione 3 in HMPA at 55 °C results in the formation of fairly stable tricyclic 4-acyl-5-hydroxytriazolines 6 in yields greatly decreasing with decreasing electrophilic character of the aryl azide reactant. Similar reaction of 4-nitrophenyl azide 1a with 2-phenylindanedione 4 affords the corresponding 5-hydroxytriazoline 7a in high isolated yield. Upon photolysis or treatment with trifluoroacetic acid the hydroxytriazolines 6 undergo exclusive decomposition to 2-arylamino-2-methylindanediones 12 through the reactive hydroxyaziridine 19 intermediates. On the other hand, upon thermolysis at 95 °C compounds 6 appear to rearrange preferentially to ring-expanded 2-arylisoquinoline-1,3-diones 13, which are believed to result eventually from Wolff rearrangement of initially formed diazo keto amides. The strongly electrophilic tosyl azide 2 reacts smoothly with 2-methylindanedione 3 in HMPA, at room temperature, to give a mixture of the 2-tosylisoquinoline-1,3-dione 14 and the isomeric 1,4-dione 17 to a comparable extent. Under similar conditions, the azide 2 reacts with 2-phenylindanedione 4 to give exclusively the isoquinoline-1,3-dione 15 in virtually quantitative yield. The products 14, 17 and 15 are ascribable to intramolecularly acid-catalysed decomposition of unstable diazocarbonyl compounds resulting from isomerization of reactive 5-hydroxy-1-tosyltriazolines adducts. An X-ray crystal structure analysis of the 4-acyl-5-hydroxytriazoline 6c has been performed.

ChemInform Abstract: Reactions of Aryl Azides with Alkenes in the Presence of Aluminum Trichloride. Formation of Novel Aziridines Fused to Seven‐ and Eight‐Membered Rings.

AbstractThe formation of the anilines (III), (IV), the 8‐azabicyclo(5.1.0)octanes and 9‐azabicyclo(6.1.0)nonanes ((VI), 10 examples) as well as that of the different products (VIII) or (X) and (XI) from the cis‐ (VII) or trans‐isohexene (IX), respectively, is explained by a mechanism via an azide‐AlCl3 complex, which after addition to the alkene forms an aziridinium‐AlCl3 complex.

Reactions of aryl azides with alkenes in the presence of aluminium trichloride. Formation of novel aziridines fused to seven- and eight-membered rings

Reactions of aryl azides (1) with cyclohexene gave 3-(arylamino)cyclohexenes (2) and trans-1-chloro-2-(arylamino)cyclohexanes (3), whereas that of (1) with cycloheptene or cis-cyclo-octene afforded novel aziridines, 8-aryl-8-azabicyclo[5.1.0]octanes(4), or 9-aryl-9- azabicyclo[6.1.0]nonanes (5), respectively. The reaction of phenyl azide (1a) with cis-4-methylpent-2-ene yielded 3-anilino-2-chloro-4-methylpentane (10), but that with the trans-alkene gave 4-anilino-2-methylpent-2-ene (7) and 3-anilino-4-methylpent-1-ene (8). The similar reaction of (1) with 3-trimethylsilylcyclohexene or 3-trimethylsilyl-cis-cyclo-octene produced only (2) or 3-(arylamino)-cis-cyclo-octenes (2′). The formation of the aziridines or the ring-opened products was explained by a mechanism via an aziridinium–AlCl3 complex formed from an azide–AlCl3 complex.

Regio- and site-selective cycloadditions: I. The reaction of aryl azides and of ethyl diazoacetate with the bis(trimethylsilyl)polyynes, Me 3Si(CC) nSiMe 3 ( n = 2 or 3)

Phenyl azide and ethyl diazoacetate add ‘ endo’ to Me 3Si(CC) 2SiMe 3. 4-Nitrophenyl azide reacts exclusively with the triple bond adjacent to silicon in Me 3Si(CC) 3SiMe 3, also in the ‘ endo’. The regio- and site-specificity exhibited in these cycloadditions is attributed to orbital rather than to steric control.

Decomposition of arylazides by thf/ [formula omitted]-butyllithium-II-isolation of 1-aryl-4,5-dihydro-5-hydroxy-1h-1,2,3-triazoles

By reaction of arylazides having no electron-withdrawing groups with the enolate ion of the acetaldehyde (formed by cycloreversion of THF in the presence of n -butyllithium), 1-aryl-4,5-dihydro-5-hydroxy-1H-1,2,3-triazoles could be isolated and then characterized. Further reaction of such hydroxytriazolines with the same enolate ion afforded substantial amounts of the corresponding N-formylanilines, confirming their intermediacy in the previously reported decomposition of arylazides by THF/ n -butyllithium. On the other hand, using alkoxides as bases, the preferred scheme of conversion of the hydroxytriazolines was found to be the known dehydration to 1-aryl-1H-1, 2,3-triazoles.

V‐triazolines. XI . Rearrangement of 1‐aryl‐4,5‐diamino‐4,5‐dihydro‐v‐triazoles

AbstractThe reaction of arylazides with 1,2‐diaminoethylenes (1a‐b) or α,β‐diaminostyrenes (1c‐f) gave N‐(1,2‐diaminoethylideneanilines (2a‐e) and N‐(1,2‐diamino‐2‐phenylethylidene)anilines (2g‐i), respectively. These amidine derivatives are formed through the rearrangement of unstable 1‐aryl‐4,5‐diamino‐v‐triazolines. The regiospecificity of the cycloaddition reaction has been elucidated on the basis of the products obtained.

Reactions of aryl azides with α-keto phosphorus ylides

Acylmethylenetriphenylphosphoranes react with aryl azides in refluxing benzene to give 1-aryl-5-substituted-1,2,3-triazoles exclusively. The regiochemistry of the reaction was resolved by comparison of the triazoles with authentic samples, prepared by the Dimroth method. From the kinetic point of view, the reaction is accelerated by electron-withdrawing substituents on the azide and electron-releasing substituents on the ylide. The polarity of the solvent has only a small effect on the reaction rate. Finally, the low entropies of activation support a concerted cycloaddition in the first step of the reaction.