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1.
The synthesis of fused [5,5]‐1,2,4‐triazoles via a tandem cyclopropane rearrangement–cyclization sequence is described. Optimization of the cyclization reaction was achieved thermally using iPrOH as the solvent in the presence of TEA. This method was applied to the preparation of 3‐substituted‐7‐aryl‐pyrrolo‐1,2,4‐triazoles in good to excellent yields. 相似文献
2.
Ytterbium perfluorooctanesulfonate [Yb(OPf)3] catalyses the highly efficient synthesis of 2,3‐dihydro‐1H‐1,5‐benzodiazepines in fluorous solvents. By simple separation of the fluorous phase containing only the catalyst, the reaction can be repeated several times. 相似文献
3.
A facile one-pot, three-component synthesis of α -aminophosphonates catalyzed by ytterbium triflate [Yb(OTf)3] in water using polyoxyethanyl α -tocopheryl sebacate (PTS) as amphiphile has been developed. The catalytic system could be readily recycled and reused several times without significant loss in its activity. 相似文献
4.
Novel 1,2,4‐triazole isonucleosides (1 and 2) were efficiently synthesized starting from D‐ribose and D‐xylose, respectively. The key steps were condensation of cyclic sulfate 8 with methyl‐1,2,4‐triazole‐3‐carboxylate and nucleophilic displacement of the tosylate 15 with methyl‐1,2,4‐triazole‐3‐carboxylate, respectively. 相似文献
5.
Johan Lindström 《合成通讯》2013,43(15):2217-2229
Treatment of N‐substituted acetamides with oxalyl chloride generates imidoyl chlorides, which react readily with aryl hydrazides. Following cyclization, triazoles can easily be obtained in moderate to good yields. 5‐Methyl triazoles can be further functionalized through α‐lithiation and subsequent reaction with an electrophile. 相似文献
6.
Pd(MeCN)2Cl2/PCy3 was found to be an efficient catalytic system for the Suzuki–Miyaura cross‐couplings of aryl chlorides with arylboronic acids under solvent‐free conditions. Furthermore, the presence of the conventional solvents had deleterious effect on the reaction. In the presence of Pd(MeCN)2Cl2, PCy3, and TBAF (tetra‐n‐butylammonium fluoride), a number of aryl chlorides including heteroaryl chlorides were coupled with arylboronic acids or heteroarylboronic acids smoothly to afford the corresponding products in moderate to excellent yields. 相似文献
7.
A simple, efficient, and practical procedure for synthesis of 2,4,5‐trisubstituted‐1H‐imidazoles via the condensation of benzoin or acetoin, aromatic aldehydes, and ammonium acetate using europium triflate [Eu(OTf)3] as a novel catalyst in high yields is described. The catalyst can be recovered conveniently and reused at least four times without any loss of activity. 相似文献
8.
《合成通讯》2013,43(14):2655-2658
Abstract Several substituted 1,2,4‐triazoles have been synthesized by a new route and characterized by IR, NMR, mass spectral, and x‐ray diffraction studies. The computer programme PASS for the prediction of biological activities established that these compounds are potential candidates for the screening. 相似文献
9.
The synthesis of unsymmetrical biaryls with a methylthio group is achieved using the air‐stable palladium–phosphinous acid complexes, [(t‐Bu)2P(OH)]2 PdCl2 (POPd), as the catalyst. A great variety of substituted bromobenzenes having electron‐withdrawing and electron‐donating functional groups in para and meta positions have been successfully coupled with 3‐methylthiophenylboronic acid. 相似文献
10.
The reaction of allylic thioureas with phenylselenenyl chloride affords 2‐amino dihydrothiazoles in excellent yields by selenium‐induced cyclization of allylic thioureas. 相似文献
11.
Total synthesis of isagarin (2) has been accomplished in five steps with 24.1% overall yield from 2‐bromonaphthoquinone (6). The key step is a palladium‐catalyzed cyclization to form a bicyclic ketal ring. 相似文献
12.
Catalyzed by ytterbium(III) triflate [Yb(OTf)3], β‐lactams were stereoselectively synthesized from imines and acetyl chlorides in ionic liquid under mild conditions. The ionic liquid and catalyst could be recycled and reused as opposed to traditional solvent–catalyst systems. 相似文献
13.
A facile, efficient, and clean procedure is described for synthesis of α,α′‐bis(substituted benzylidene) cycloalkanones with good yields by the reaction of cycloalkanones with aromatic aldehydes using Cu(OTf)2 as catalyst. The catalyst was easily recovered and reused without loss of activity. 相似文献
14.
P. M. Veeresha Sharma 《合成通讯》2013,43(9):1381-1388
Various substituted 3‐phenylindole 2‐carboxylates (1a–c) were prepared according to the literature methods. These carboxylates (1a–c) on reaction with thiosemicarbazide yielded 5‐substituted‐3‐phenylindol‐2‐(1,2,4‐triazole‐3‐thione) (2a–c) on refluxing in pyridine for 8 h. The 5‐substituted‐3‐phenylindole‐2‐[1,2,4‐triazolo‐3‐thioacetic acid] (3a–c) were prepared from 5‐substituted‐3‐phenyl indole‐2‐[1,2,4‐triazole‐3‐thione] (2a–c) on reaction with an appropriate alkylating agent and sodium acetate in acetic acid. Further, (3a–c) were reacted with acetic anhydride to bring about a cyclocondensation reaction to yield 5‐substituted‐3‐phenylindol‐2‐thiazolo(2,3‐b)‐triazole (4a–c). The 5‐substituted‐3‐phenylindole‐2‐[1,2,4‐triazolo‐3‐acetic acid] (3a–c) were reacted with o‐phenylenediamino dihydrochloride in ethylene glycol to yield 5‐substituted‐3‐phenylindole‐1,2,4‐triazolo‐3′‐yl‐thiomethyl)benzimidazoles (5a–c). 相似文献
15.
A convenient and cost‐effective synthesis of 6‐methoxytryptamine (1), starting from commercially available phthalimide and 1‐bromo‐3‐chloropropane via PTC N‐alkylation, PTC C‐alkylation, Japp–Klingemann reaction, hydrolysis, and decarboxylation, has been accomplished with a 44% overall yield. 相似文献
16.
In the presence of metallic magnesium, the homocoupling reaction of aryl bromides catalyzed by iron triflate was carried out readily in one pot. The catalyst was used successfully in this coupling reaction without preparation of Grignard reagent in advance. Meanwhile, the catalyst was recovered easily and reused smoothly with only a little loss of its activity. 相似文献
17.
Some novel triazolo[4,3‐a]triazines derivatives were synthesized by reaction of N‐cyanoimidates and N‐ethoxycarbonylimidates with 3‐alkyl‐5‐amino‐1‐phenyl‐1,2,4‐triazoles. 相似文献
18.
Zinc hydroxyapatite (ZnHAP) is an effective heterogeneous catalyst for the (2+3)‐cycloaddition of sodium azide with nitriles to afford 5‐substituted 1H‐tetrazoles in good yields. The catalyst is recovered and reused for several cycles with consistent activity. 相似文献
19.
A mild and operationally simple procedure by Pd-catalyzed cross-coupling of acyl chlorides with in situ–generated alkynylzinc derivatives was developed, giving the corresponding ynones in good yields.
Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® full experimental and spectral details. 相似文献
20.
Sergey I. Kovalenko Oksana V. Krivoshey Svetlana V. Shishkina Oleg V. Shishkin 《合成通讯》2013,43(21):3719-3727
4‐Hydrazinoquinazoline was found to form new 2‐(3,4‐dihydro‐3oxo‐2H‐[1,2,4]triazino[4,3‐c]quinazolin‐4‐yl)acetic acid with maleic anhydride in on‐step sequence. Proposed heterocyclization includes, probably, acylation reaction followed by intramolecular uncleophilic addition. 相似文献