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1.
Mark R. Brei R. Hunter Cooke III Daniel J. Hanson Christina T. Gray 《高分子科学杂志,A辑:纯化学与应用化学》2016,53(7):413-423
Azide alkyne cycloaddition was applied to step growth polymerization of the diazido monomer, di(3-azido-2-hydroxypropyl) ether of bisphenol-A (DAHP-BPA) with either tetraethyleneglycol dipropargyl ether (TEGDPE) or tetraethyleneglycol dipropiolate (TEGDP). Polymerizations were conducted without catalyst and in the presence of Cu(I) or Ru(II) complex. The resulting oligomers and polymers were characterized using 1H- and 13C-NMR spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), with an emphasis on the relative abundance of 1,4- vs. 1,5-disubstituted regioisomeric 1,2,3-triazoles. Uncatalyzed reaction of DAHP-BPA/TEGDPE at 70°C yielded a 55/45 mixture of 1,4/1,5-disubstituted triazoles; reaction was slow and residual alkyne end groups were observed, suggesting attritional loss of azide. Catalyzed with Cu(PPh3)3Br, the same system yielded 93/7, 1,4/1,5-disubstituted triazoles, and few residual end groups were detected, consistent with higher molecular weight and controlled 1:1 depletion of azide and alkyne. Cp*RuCl(COD) catalyst was not soluble in the bulk system, necessitating solution polymerization in THF. Ru(II) yielded 6/94, 1,4/1,5-disubstituted triazoles, and MALDI-TOF-MS showed an end group composition similar to that observed with Cu(I). Uncatalyzed reaction of the DAHP-BPA/TEGDP system, involving the more reactive propiolate, yielded a high proportion (85%) of 1,4-disubstituted triazole linkages, and MALDI-TOF-MS revealed a controlled 1:1 depletion of azide and alkyne groups. 相似文献
2.
[reaction: see text] 1,4-Disubstituted 1,2,3-triazoles are obtained in excellent yields by a convenient one-pot procedure from a variety of readily available aromatic and aliphatic halides without isolation of potentially unstable organic azide intermediates. 相似文献
3.
An efficient method is described for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles in high yields from a variety of Baylis-Hillman acetates and terminal alkynes with sodium azide using CuI as a catalyst, in either water or polyethylene glycol (PEG). This procedure is operationally simple and environmentally benign. Polyethylene glycol (PEG) serves as an efficient reusable solvent with higher efficiency. 相似文献
4.
John P. Chupp 《Journal of heterocyclic chemistry》1971,8(4):557-563
Reaction of phosgene with cyclohexylidene amines gives good yields of (1-eyclohexen-l-yl)-carbamoyl chlorides ( 1 ). Compound 1 can be converted to the corresponding eneearbamoyl azide ( 2 ), which on pyrolysis gives an improved synthesis of 1-substituted-4,5,6,7-tetrahydro-3-indazolinones ( 7 ). When 1 is substituted by an allylic rather than alkyl or aryl group, the major products are 4-imidazolin-2-ones ( 8 ) accompanied by only minor amounts of 7 . The thermolysis reaction has been extended to N-allylcarbamoyl azides in general, thus providing a new and facile synthesis for 1,4-disubstituted 4-imidazolin-2-ones (9). A tentative mechanism is advanced, involving intermediate azide addition to the allylic double bond. 相似文献
5.
Ya-Bin Zhao 《Tetrahedron letters》2006,47(10):1545-1549
A copper(I) catalyst in a mixture of the ionic liquid [bmim][BF4] and water, can effect three-component reaction of halides, sodium azide and alkynes to form 1,4-disubstituted 1,2,3-triazoles in good to high yields. The method is efficient and environmentally friendly. 相似文献
6.
Yu N Wang C Zhao F Liu L Zhang WX Xi Z 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(18):5670-5679
Addition cyclization of 1,2,3,4-tetrasubstituted 1,4-dilithio-1,3-dienes (Type I) with four equivalents of various aromatic nitriles in the presence of hexamethylphosphoramide (HMPA) gives exclusively fully substituted pyridines in moderate to good yields. Similarly, trisubstituted pyridines can be prepared by the reaction of 2,3-dialkyl- or diaryl-substituted 1,4-dilithio-1,3-dienes (Type II) with nitriles. However, five- or six-membered-ring fused 2,3-disubstituted 1,4-dilithio-1,3-dienes (Type III) reacted with various aromatic and aliphatic nitriles without alpha-hydrogen atoms to afford tricyclic Delta1-bipyrrolines in high yields. The reaction of six-membered-ring fused 2,3-disubstituted 1,4-dilithio-1,3-diene (Type III) with 2-cyanopyridine afforded the corresponding pyridine, and no tricyclic Delta1-bipyrroline was observed. Seven-membered-ring fused dilithiodienes reacted with PhCN or trimethylacetonitrile to afford the corresponding pyridines in good yield. When 1,2,3,4-tetrasubstituted dilithio reagents (Type I) were treated with Me3SiCN, a tandem silylation/intramolecular substitution process readily occurred to yield siloles, whereas the reaction of 2,3-disubstituted dilithio reagents (Types II and III) with Me3SiCN gave rise to (Z,Z)-dienylsilanes with high stereoselectivity. These results revealed that the formation of tricyclic Delta1-bipyrrolines, pyridines, siloles, and (Z,Z)-dienylsilanes are strongly dependent on the substitution patterns of the dilithio butadienes and the nature of the nitriles employed. 相似文献
7.
The reaction of α-tosyloxy ketones, sodium azide, and terminal alkynes in presence of copper(I) in aqueous polyethylene glycol afforded regioselectively 1,4-disubstituted 1,2,3-triazoles in good yield at ambient temperature. The one-pot exclusive formation of 1,4-disubstituted 1,2,3-triazoles involves in situ formation of α-azido ketones, followed by cycloaddition reaction with terminal alkyne. The generality of this one-pot method was demonstrated by synthesizing an array of diverse 1,4-disubstituted 1,2,3-triazoles. 相似文献
8.
Treatment of 3,(5)-(di)chloro-2H-1,4-(benz)oxazin-2-ones with diazo compounds or sodium azide yields bi(tri)cyclic compounds which can be converted into [1,2,3]triazoles or 1,5-disubstituted tetrazoles via reactions with nucleophiles as methanol, water and amines. 相似文献
9.
The first study of a copper(I)-catalyzed azide-alkyne click reaction in ionic liquids (ILs) is reported. The cycloaddition of a sugar azide with a sugar acetylene (CuI, i-Pr2EtN, 80 degrees C) was carried out in 10 ILs as well as in standard molecular solvents (toluene and DMF) to give the 1,4-disubstituted triazole-linked C-disaccharide. The highest yields (84 and 95%) were registered in Ammoeng 110 and [C(8)dabco][N(CN)(2)]. The latter solvent was recycled in four subsequent reactions without loss of the reaction efficiency. Reactions carried out in the absence of the Hünig's base afforded mixtures of 1,4- and 1,5-disubstituted triazole regioisomers. 相似文献
10.
A structurally well-defined copper(I) isonitrile complex is shown to be an efficient, heterogeneous catalyst for the Huisgen azide-alkyne 1,3-dipolar cycloaddition under mild conditions in water. Notably, this catalyst can also be utilized in a three-component reaction of halides, sodium azide and alkynes to form 1,4-disubstituted 1,2,3-triazoles in high yields. Furthermore, it can be readily recovered by precipitation and filtration and recycled for at least five runs without significant loss of activity. 相似文献
11.
Various aliphatic hydrocarbons and the side chains of aromatic hydrocarbons were chlorinated in subcritical carbon tetrachloride. Chlorination of aromatic compounds including 1,4-disubstituted benzenes was investigated. Ketones and sulfones were stable under the employed conditions. Sulfoxides were converted into sulfides in a low to modest yields. The coupling adducts between olefins and carbon tetrachloride were obtained from the reactions of olefins. 相似文献
12.
Copper (I) or copper (II) salts and oxides promote regioselective head-to-head additive dimerization of aromatic and aliphatic terminal alkynes in the presence a catalytic amount of diethylphosphite. The reaction proceeds under ambient conditions without any added base with the formation of 1,4-disubstituted 1,3-enynes with the E isomer as major product in good to excellent yields. A plausible mechanism for additive dimerization of terminal alkynes is proposed. 相似文献
13.
2,6-Dimethyl-3,5-bis(ethoxycarbonyl)-1,4-dihydropyridine (dihydropyridine Hantzsch ester, DHPHE) and CuSO4 · 5H2O efficiently accelerated azide–alkyne cycloaddition reactions of both aliphatic and aromatic substrates and gave 1,4-disubstituted 1,2,3-triazoles as the only isomer in good to excellent yields at room temperature with 1 mol% of CuSO4 · 5H2O/DHPHE (1:1 in molar ratio). The reaction could be carried out smoothly in methanol in air with high efficiency. DHPHE may play multiple important roles in the reaction: a reducing reagent to generate the catalytic center copper(I) from CuSO4, a base to help form the intermediate acetylide, and a ligand to stabilize the catalytic copper(I) species via coordination after being transformed to pyridine derivative.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
14.
A one-pot protocol for the synthesis of triazole-annulated polyheterocycles via metal-catalyzed coupling of internal 1,4-disubstituted 1,3-diynes and organic azides has been described. The mechanistic rationale for the reaction suggests tandem cyclizations involving copper-catalyzed cycloaddition and 6-endo carbocyclization reactions. The cascade cyclization leads to an increase in molecular complexity to furnish naphtho[1,2-d]triazoles in satisfactory yields. The generality of the method has been demonstrated by using a series of aromatic/aliphatic azides and symmetrical internal 1,3-diynes. 相似文献
15.
Nayer H. Sultana Stephen M. Kelly Bassam Mansoor Mary O'neill 《Liquid crystals》2007,34(11):1307-1316
We report the synthesis of oligophenylene polycatenar liquid crystals incorporating 1,4-disubstituted phenyl rings joined by a direct carbon carbon bond and some pyrimidine analogues. The nature of the linkages does appear to affect the mesomorphism significantly. The ratio of the aromatic core to the aliphatic chains is varied systematically by changing the number of 1,4-disubstituted phenyl rings and the length of the aliphatic chains. This strongly influences the transition temperatures of the mesophases. Some of the compounds are columnar over an extended temperature range of more than 200°C with melting points below room temperature. We suggest that a combination of the poor overlap of the conjugated electron system of the molecular cores making up the columnar structure and the high concentration of aliphatic chains leads to a low charge-carrier mobility. 相似文献
16.
An experimentally simple sequential one-pot RuAAC reaction, affording 1,5-disubstituted 1H-1,2,3-triazoles in good to excellent yields starting from an alkyl halide, sodium azide, and an alkyne, is reported. The organic azide is formed in situ by treating the primary alkyl halide with sodium azide in DMA under microwave heating. Subsequent addition of [RuClCp*(PPh(3))(2)] and the alkyne yielded the desired cycloaddition product after further microwave irradiation. 相似文献
17.
Anirban Garg Abdul Aziz Ali Krishnaiah Damarla Arvind Kumar Diganta Sarma 《Tetrahedron letters》2018,59(45):4031-4035
A facile, efficient and mild copper catalyzed strategy for cascade synthesis of various 1,4-disubstituted 1,2,3-triazoles from arylboronic acids, sodium azide and alkynes was developed by using aqueous bile salt NaDC solution as an accelerating medium. Low catalyst loading (only 1?mol% Cu source was sufficient for in situ generation of azide followed by azide–alkyne coupling), green solvent, use of bio-surfactant as additive and short reaction time make this protocol highly accessible and environment friendly. 相似文献
18.
A copper-catalyzed decarboxylation/cycloaddition cascade of alkynyl carboxylic acids with azide has been developed. This reaction exhibits good functional group tolerance and wide substrate scope, provides an efficient way to construct 1,4-disubstituted 1,2,3-triazoles. 相似文献
19.
Alberto Bargagna Pietro Schenone Mario Longobardi 《Journal of heterocyclic chemistry》1985,22(6):1471-1473
1,4-Cycloaddition of phenylchloroketene (prepared in situ from α-chlorophenylacetyl chloride and triethyl-amine) to a number of N,N-disubstituted (E)-2-aminomethylenecyclohexanones gave the corresponding adducts, namely N,N-disubstituted 4-amino-3-chloro-3,4,5,6,7,8-hexahydro-2H-1-benzopyran-2-ones III in the case of aliphatic N,N-disubstitution or aromatic N-monosubstitution. Purification of III was possible only in the case of IIIh (NR2 = NMePh), therefore they were dehydrochlorinated in situ with DBN to give the title compounds in moderate overall yields. 相似文献
20.
An organocatalyzed asymmetric Michael addition of α-cyano acetates to (E)-1,4-diaryl-2-buten-1,4-diones was realized. The reactions afforded various enantioenriched α,α-disubstituted α-cyano acetates with good yields (up to 99%), moderate to good diastereoselectivities (up to 13.3:1) and moderate to good enantioselectivities (up to 94% ee). Furthermore, one of the products was subjected to Paal–Knorr cyclization to provide an α-furanyl-α,α-disubstituted α-cyano acetate in good yield with moderate enantioselectivity. Thus an indirect asymmetric α-heteroarylation of α-cyano acetates has been well established. 相似文献