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1.
Cobalt‐Catalyzed Cyclization of N‐Methoxy Benzamides with Alkynes using an Internal Oxidant through C−H/N−O Bond Activation 下载免费PDF全文
Ganesan Sivakumar Arjun Vijeta Dr. Masilamani Jeganmohan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5899-5903
The cyclization of substituted N‐methoxy benzamides with alkynes in the presence of an easily affordable cobalt complex and NaOAc provides isoquinolone derivatives in good to excellent yields. The cyclization reaction is compatible with a range of functional group‐substituted benzamides, as well as ester‐ and alcohol‐substituted alkynes. The cobalt complex [CoIIICp*(OR)2] (R=Me or Ac) serves as an efficient catalyst for the cyclization reaction. Later, isoquinolone derivatives were converted into 1‐chloro and 1‐bromo substituted isoquinoline derivatives in excellent yields in the presence of POCl3 or PBr3. 相似文献
2.
NaHSO4•H2O has been used as an efficient catalyst for the one-pot preparation of 14H-[(un)substituted phenyl]-dibenzo[a,j]xanthene leuco-dye derivatives by condensation of β-naphthol with substituted benzaldehydes under microwave and thermal conditions. This method has the advantages of high yields, a green reaction, an efficient and cost-effective method, simple procedures, short reaction time, and easy workup. 相似文献
3.
Sivakolundu Bhuvaneswari Dr. Masilamani Jeganmohan Dr. Chien‐Hong Cheng Prof. Dr. 《化学:亚洲杂志》2010,5(1):141-146
N‐Methyl indole reacts with but‐2‐yn‐1‐ol in the presence of PtCl2 in MeOH giving indole derivatives having a substituted 3‐oxobutyl group at the 3‐position in good yield. Under the reaction conditions, various substituted indoles and substituted propargyl alcohols are successfully involved in the reaction giving the corresponding addition products in good to moderate yields. The catalytic reaction can be further extended to N‐phenyl pyrrole. In the present multi‐step reaction, PtCl2 likely plays dual roles: as the catalyst for the rearrangement of propargyl alcohols to the corresponding alkenyl ketones and as the catalyst for the addition of indoles to the alkenyl ketones. Experimental evidence is provided to support the proposed mechanism. 相似文献
4.
《Journal of heterocyclic chemistry》2018,55(4):957-963
An exceedingly and highly efficient procedure has been described for the synthesis of substituted N‐3‐diaryl‐1,8‐naphthyridin‐2‐amines by the reaction of 2‐chloro‐3‐aryl‐1,8‐naphthyridines with various anilines in the presence of N‐methyl‐2‐pyrrolidone and K2CO3 under thermal green solvent‐free conditions. The significant features of this green reaction include very good yields in purity, simple experimental, short reaction time, easy workability, and avoidance of toxic solvents. All synthesized compounds have been evaluated for their antibacterial activity. 相似文献
5.
《应用有机金属化学》2017,31(9)
Thiazolopyrimidine derivatives are well known because of their excellent therapeutic properties. In this investigation, an effective one‐pot three‐component method is described for the synthesis of novel 2‐[(Z )‐1‐(substituted phenyl)methylidine]‐7‐methyl‐3‐oxo‐5‐(substituted phenyl)‐2,3‐dihydro‐5H ‐thiazolo[3,2‐a]pyrimidine‐6‐carboxilic acid tert ‐butyl ester derivatives by condensation reaction of 3,4‐dihydropyrimidine‐2(1H )‐thiones, various aromatic aldehydes and chloroacetyl chloride under reflux conditions in the presence of Fe3O4@l ‐arginine nanoparticles as a magnetically reusable and eco‐friendly catalyst with short reaction times and moderate yields. The chemical structures of all synthesized compounds were determined using infrared, 1H NMR and 13C NMR spectroscopies. In vitro antimicrobial activities of 3,4‐dihydropyrimidine‐2(1H )‐thiones and newly fused thiazolo[3,2‐a]pyrimidine derivatives were examined using the well diffusion method against diverse pathogenic strains, namely Staphylococcus aureus ATCC 6538, S. epidermidis ATCC 12228, Escherichia coli ATCC 8739 and Pseudomonas aeruginosa ATCC 9027 (bacteria), Candida albicans ATCC 10231 (yeast) and Aspergillus niger ATCC 16404 (fungus). The compounds having 2‐hydroxy, 4‐hydroxy, 2‐chloro and 4‐chloro groups attached to the phenyl ring on the pyrimidine and 4‐CH3, 4‐OCH3 and 3‐NO2 groups attached to benzylidine on the thiazolo moiety showed significant antibacterial activity. 相似文献
6.
Bhimapaka China Raju Gannerla Saidachary Jaladi Ashok Kumar Balasubramanian Sridhar 《Helvetica chimica acta》2011,94(2):248-253
Ethyl 2‐(chloromethyl)‐2‐hydroxy‐2H‐chromene‐3‐carboxylates 2a – 2j have been synthesized by reaction of substituted salicylaldehydes with ethyl 4‐chloro‐3‐oxobutanoate, in the presence of piperidine in CH2Cl2 at room temperature, in good yields. 相似文献
7.
The solvent effect on a nucleophilic substitution reaction of 2‐ and 4‐chloro‐3,5‐dinitrobenzotrifluoride with substituted anilines was studied in methanol, acetonitrile, and toluene at 25°C. This reaction is of second order, except 2‐chloro‐3,5‐dinitrobenzotrifluoride in toluene shows third order. The kA values are found to be dependent on the substituent in aniline and give good Hammett correlations. The obtained ρ values are ?4.07 and ?4.62, for the reaction of anilines with 2‐chloro‐3,5‐dinitrobenzotrifluoride in methanol and acetonitrile, respectively. The ρ values for the reaction of the anilines with 4‐chloro‐3,5‐dinitrobenzotrifluoride are ?3.38, ?4.11, and ?4.34 in methanol, acetonitrile, and toluene, respectively. The reaction of the former compound with anilines in toluene shows a second order in aniline. The dependence of the reaction on the external base such as DABCO suggests a proton transfer controlling step. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 777–786, 2009 相似文献
8.
Anthony L. Spek Johannes Canisius Hans Preut Norbert Krause 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1065-1066
The title compound, di‐μ‐chloro‐bis{[(2,3,4‐η)‐ethyl 6,6‐dimethyl‐5‐oxohept‐2‐enoato]palladium(II)}, [Pd2Cl2(C11H17O3)2], is a binuclear chloro‐bridged palladium allyl complex that was obtained serendipitously From the reaction of 6,6‐dimethyl‐2‐hepten‐4‐ynoate with Na2PdCl4 in water‐containing alcohol. The allyl group is substituted with an ester and a tert‐butylcarboxy group. The dimeric molecules link via C—H?O contacts into a two‐dimensional network parallel to the bc plane. 相似文献
9.
Efficient One‐Pot Access to 2,9‐Dihydrothiopyrano[2,3‐b]indole Scaffolds Showing Large Stokes Shifts
A simple, mild and efficient one‐pot approach for the construction of 2‐aryl‐3‐nitro‐2,9‐dihydrothiopyrano[2,3‐b]indole derivatives has been realized in CH2Cl2 medium at ambient temperature via three‐component tandem reaction of N‐protected‐2‐chloro‐3‐formylindoles, sodium hydrosulfide and β‐substituted nitroolefins/δ‐substituted nitrodienes using DABCO (10 mol%) as an organocatalyst, followed by dehydration in the presence of activated molecular sieves (4 Å). The significant advantages of this protocol are simple operation, shorter reaction time, high atom economy, good to high yields (73% –89%) and wider substrate scope. In addition, all the synthesized compounds have shown the large positive Stokes shift values (5632–6081 cm?1). 相似文献
10.
Giuliana Biagi Fabio Ciambrone Irene Giorgi Oreste Livi Valerio Scartoni Pier Luigi Barili 《Journal of heterocyclic chemistry》2002,39(5):889-893
New tricyclic 1,2,3‐triazolo‐1,2,4‐triazolo‐pyridazine derivatives, bearing a methyl substituent on the 1,2,3‐triazole ring, were prepared as potential biological agents. N‐Methylation of dimethyl 1,2,3‐triazole‐4,5‐dicarboxylate allowed synthesis of the isomeric 1‐methyl‐4,7‐dihydroxy and 2‐methyl‐4,7‐dihydroxy triazolo‐pyridazines 4a and 4b which, by a chlorination reaction, gave the corresponding 1‐methyl‐4‐chloro‐( 6a ), 1‐methyl‐7‐chloro‐ ( 6b ) and 2‐methyl‐4‐chloro‐ ( 9 ) substituted 1,2,3‐triazolo‐pyridazines. The nucle‐ophilic substitution with hydrazine hydrate and the suitable cyclization to form the 1,2,4‐triazole ring, provided the expected tricyclic isomeric derivatives 8a, 8b and 11 respectively. The p‐methoxybenzyl substituent, introduced as a leaving group to obtain either v‐triazolo‐pyridazine or v‐triazolo‐s‐triazolo‐pyri‐dazine derivatives unsubstituted on the 1,2,3‐triazole ring, appeared inadequate. Some compounds underwent binding assays toward the adenosine A1and A2A receptors. 相似文献
11.
Michael Lewis Charles L. Barnes Rainer Glaser 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):393-396
The crystal structure of the title mixed azine, C17H17ClN2O, contains four independent molecules, A–D, and molecule B is disordered. All four molecules have an N—N gauche conformation, with C—N—N—C torsion angles of 136.5 (4), 137.0 (4), ?134.7 (4) and ?134.7 (4)°, respectively. The phenyl rings are also somewhat twisted with respect to the plane defined by Cipso and the imine bond. On average, the combined effect of these twists results in an angle of 64.7° between the best planes of the two phenyl rings. Arene–arene double T‐contacts are the dominant intermolecular interaction. The methoxy‐substituted phenyl ring of one azine molecule interacts to form a T‐contact with the methoxy‐substituted phenyl ring of an adjacent molecule and, similarly, two chloro‐substituted phenyl rings of neighboring molecules interact to form another T‐contact. The only exception is for molecule B, for which the disorder leads to the formation of T‐contacts between methoxy‐ and chloro‐substituted phenyl rings. The prevailing structural motif of T‐contact formation between like‐substituted arene rings results in a highly dipole‐parallel‐aligned crystal structure. 相似文献
12.
Chiral Ammonium Betaine‐Catalyzed Highly Stereoselective Aza‐Henry Reaction of α‐Aryl Nitromethanes with Aromatic N‐Boc Imines 下载免费PDF全文
Dr. Daisuke Uraguchi Keigo Oyaizu Haruhiro Noguchi Prof. Dr. Takashi Ooi 《化学:亚洲杂志》2015,10(2):334-337
A highly stereoselective aza‐Henry reaction of α‐aryl nitromethanes with aromatic N‐Boc imines was established by using C1‐symmetric chiral ammonium betaine as a bifunctional organic base catalyst. Various substituted aryl groups for both imines and nitromethanes were tolerated in the reaction, and a series of precursors for the synthesis of unsymmetrical anti‐1,2‐diaryl ethylenediamines was provided. 相似文献
13.
Transformation of N‐alkylated anilines to N‐aryloxamates was studied using ethyl 2‐diazoacetoacetate as an alkylating agent and dirhodium tetraacetate (Rh2(OAc)4) as the catalyst. The general applicability of the reaction as a synthetic method for N‐aryloxamates was studied with a number of substituted N‐alkylated anilines. The results revealed that the oxamate was formed by a radical reaction with molecular O2 and Rh2(OAc)4 as initiator. 相似文献
14.
Zhong‐Xia Wang Li‐Zhuang Chen Bei Li Guang‐Fan Han 《Journal of heterocyclic chemistry》2015,52(6):1663-1668
The Gewald reactions of 5‐substituted‐1,3‐cyclohexanedione, malononitrile, and powdered sulfur were carried out to give the corresponding products 2‐amino‐5‐substituted‐7‐oxo‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carbonitrile derivatives 1 . The intermediate enamines 2 were prepared by reaction of compounds 1 and 5‐substituted‐1,3‐cyclohexanedione with hydrochloric acid as catalyst. The title compounds 11‐amino‐2,8‐substituted‐2,3,8,9‐tetrahydrobenzo[4,5]thieno[2,3‐b]quinolinone 3 were synthesized by cyclization of compounds 2 in the presence of K2CO3 and Cu2Cl2. The structures of all compounds were characterized by elemental analysis, IR, MS, and 1H‐NMR spectra. 相似文献
15.
Kensuke Okuda Shigeki Takarada Takashi Hirota Kenji Sasaki 《Journal of heterocyclic chemistry》2015,52(3):780-792
Libraries of tricyclic 2‐substituted 4‐alkylamino‐9‐chloro‐5,6‐dihydropyrimido[5,4‐d]benzazepines and tetracyclic 12‐substituted 8‐chloro‐1,2,5,6‐tetrahydro‐4H‐imidazo[1′,2′:1,6]pyrimido[5,4‐d]benzazepines were synthesized as part of our research to develop new effective antiplatelet drugs. Several alkyl and aryl groups were used as substituents at the 2‐position. Evaluation of the effects of the newly synthesized compounds on collagen‐induced platelet aggregation revealed several promising antiplatelet candidates with potencies superior to aspirin. 相似文献
16.
Diana C. Fager Ryan J. Morrison Amir H. Hoveyda 《Angewandte Chemie (International ed. in English)》2020,59(28):11448-11455
A method for catalytic regio‐ and enantioselective synthesis of trifluoromethyl‐substituted and aryl‐, heteroaryl‐, alkenyl‐, and alkynyl‐substituted homoallylic α‐tertiary NH2‐amines is introduced. Easy‐to‐synthesize and robust N‐silyl ketimines are converted to NH‐ketimines in situ, which then react with a Z‐allyl boronate. Transformations are promoted by a readily accessible l ‐threonine‐derived aminophenol‐based boryl catalyst, affording the desired products in up to 91 % yield, >98:2 α:γ selectivity, >98:2 Z:E selectivity, and >99:1 enantiomeric ratio. A commercially available aminophenol may be used, and allyl boronates, which may contain an alkyl‐, a chloro‐, or a bromo‐substituted Z‐alkene, can either be purchased or prepared by catalytic stereoretentive cross‐metathesis. What is more, Z‐trisubstituted allyl boronates may be used. Various chemo‐, regio‐, and diastereoselective transformations of the α‐tertiary homoallylic NH2‐amine products highlight the utility of the approach; this includes diastereo‐ and regioselective epoxide formation/trichloroacetic acid cleavage to generate differentiated diol derivatives. 相似文献
17.
Helio G. Bonacorso Cleber A. Cechinel Marli R. Oliveira Michelle B. Costa Marcos A. P. Martins Nilo Zanatta Alex F. C. Flores 《Journal of heterocyclic chemistry》2005,42(6):1055-1061
A new series of 4‐[3‐alkyl(aryl)(heteroaryl)‐5‐hydroxy‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐pyrazol‐1‐yl]‐7‐chloroquinolines, where [alkyl = CH3; aryl = C6H5, 4‐CH3C6H4, 4‐FC6H4, 4‐ClC6H4, 4‐BrC6H4, 4‐CH3OCgH4, 4‐NO2CgH4, 4‐biphenyl, 1‐naphthyl; heteroaryl = 2‐furyl and 2‐thienyl] has been regiospecifi‐caly obtained from the reaction of 7‐chloro‐4‐hydrazinoquinoline with 4‐substituted‐l,1,1‐trifluoro‐4‐methoxybut‐3‐en‐2‐ones in 61 ‐ 96 % yield. Subsequently, dehydration reaction of 4,5‐dihydropyra‐zolylquinolines under acid conditions furnished a new series of 4‐(3‐substituted‐5‐trifluoromethyl‐1H‐pyra‐zol‐1‐yl)‐7‐chloroquinolines in 73 ‐ 96 % yield. 相似文献
18.
Highly efficient AgNO3‐catalyzed approach to 2‐(benzo[d]azol‐2‐yl)phenols from salicylaldehydes with 2‐aminothiophenol, 2‐aminophenol and benzene‐1,2‐diamine 下载免费PDF全文
A new, convenient and efficient AgNO3‐catalyzed strategy for the preparation of 2‐(benzo[d]azol‐2‐yl)phenol derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2‐aminothiophenol, 2‐aminophenol or benzene‐1,2‐diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO3 as a readily available and low‐cost benign oxidant at low catalyst loadings with excellent functional group tolerance. 相似文献
19.
Anthony Linden Agnieszka Majchrzak Jovita Cavegn Grzegorz Mloston Heinz Heimgartner 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o480-o484
The four oligosulfanes, bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)disulfane, C16H24Cl2O2S2, (III), 1,3‐bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)trisulfane, C16H24Cl2O2S3, (V), 1,4‐bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)tetrasulfane, C16H24Cl2O2S4, (VII), and 1,6‐bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)hexasulfane, C16H24Cl2O2S6, (VIII), all have similar geometric parameters, with the C—C bond lengths involving the chloro‐substituted cyclobutanyl C atom being elongated to about 1.59 Å. There are two molecules in the asymmetric units of the tri‐ and tetrasulfanes, and the molecules in the latter compound have local C2 symmetry. The molecule of the hexasulfane has crystallographic C2 symmetry. Most of the cyclobutanyl rings are not perfectly planar and have slight but varying degrees of distortion towards a flattened tetrahedron. The polysulfane chain in each structure has a helical conformation, with each additional S atom in the chain adding approximately one quarter of a turn to the helix. 相似文献
20.
The Use of Pinner Type Reaction for the Synthesis of New Indeno[2,1‐c]pyridine‐4‐carbonitrile Derivatives 下载免费PDF全文
Prashant S. Nikam Shivaraj P. Patil Shrikant B. Kanawade Sachin A. Gangurde Meenakshi Rathi Raghunath B. Toche 《Journal of heterocyclic chemistry》2015,52(1):150-155
An efficient and convenient route was developed for the synthesis of new pyridinecarbonitrile derivatives by using the Pinner type of reaction. The 2‐((E)‐2‐((dimethylamino)methylene)‐1,2‐dihydro‐5,6‐dimethoxyinden‐3‐ylidene) malononitrile 2 was reacted in the presence of dry HCl gas to yield 3‐chloro‐6,7‐dimethoxy‐9H‐indeno[2,1‐c]pyridine‐4‐carbonitrile ( 3 ) in good yield. The SNAr reaction on compound 3 with various nucleophiles yielded 3‐substituted pyridinecarbonitriles 4 , 5 , 6 , 7 , 8 , 9 in moderate to good yield. 相似文献