共查询到20条相似文献,搜索用时 15 毫秒
1.
Vladislav Yu. Korotaev Igor B. Kutyashev Vyacheslav Ya. Sosnovskikh 《Heteroatom Chemistry》2005,16(6):492-496
The reaction of activated trihalome‐ thylsubstituted alkenes with salicylaldehydes in the presence of triethylamine gives 3‐substituted 2‐trifluo‐ romethylchroman‐4‐ols and 2‐trifluoro(trichloro)methyl‐2H‐chromenes in high yields. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:492–496, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20146 相似文献
2.
溴化(a-噻吩甲酰基)甲基三苯鉮1与3-取代苯甲叉基-2,4-戊二酮 2以碳酸钾为碱,在苯中55℃条件下反应,可以较好的收率、高立体选择性地生成反-2-(a-噻吩甲酰基)-3-取代苯基-4-乙氧羰基-5-甲基-2,3-二氢呋喃3。产物结构均经波谱予以确定。本文还提出了生成产物的可能机理。 相似文献
3.
Helio G. Bonacorso Mauro N. Muniz Arci D. Wastowski Nilo Zanatta Marcos A. P. Martins 《Heteroatom Chemistry》2003,14(2):132-137
A convenient method for the synthesis of a novel series of 11, specifically substituted, noncondensed 5,5‐bicycles 2‐[3‐phenyl‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐pyrazol‐1‐yl]‐4‐aryl‐5‐alkylthiazoles ( 3a–k ; 65–94% yield) from the reactions of 3‐phenyl‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐1‐pyrazolethiocarboxyamide ( 1 ) with substituted 2‐bromo‐4′‐acetophenones ( 2a–f ) and 2‐bromo‐4′‐propiophenones ( 2g–k ) is reported. Dehydration of compounds 3a–k with a mixture of concentrated sulfuric acid/chloroform furnished the corresponding 2‐[3‐phenyl‐5‐trichloromethyl‐1H‐pyrazol‐1‐yl]‐4‐aryl‐5‐alkylthiazoles ( 4a–k ) in good yields (61–93%). © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:132–137, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10113 相似文献
4.
P. Haranath M. F. Stephen Babu U. Anasuyamma C. Naga Raju C. Suresh Reddy 《Heteroatom Chemistry》2005,16(7):572-575
Novel 3 substituted 1,5‐dihydro‐2,4,3‐benzodioxaphosphepine 3‐oxides ( 5a–h ) were synthesized by reacting 1,2‐benzenedimethanol ( 1 ) with phosphorus tribromide in the presence of triethylamine at 0–30°C and subsequent reaction of the monobromide ( 2 ) with different Grignard reagents ( 3 ) at room temperature. The products ( 4 ) were converted to corresponding oxides 5a–i by oxidation with H2O2 at room temperature. The chemical structures of all the products were confirmed by analytical, IR and NMR (1H, 13C, and 31P) spectral data. Their antifungal and antibacterial activity is also evaluated. Most of these compounds exhibited moderate antimicrobial activity in the assay. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:572–575, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20154 相似文献
5.
A base‐catalyzed condensation of diacetamido sulfides [(RNHCOCH2)2S)] with glyoxal affording thiophene‐2,5‐dicarboxylic acid bis‐aryl(alkyl)amides has been accomplished under mild conditions. Excellent results were readily obtained when R was a substituted 3‐nitrophenyl, 4‐nitrophenyl, 4‐chlorophenyl group, but the yield was poor when R was cyclohexyl. Unknown compounds were characterized by elemental analyses, IR, 1H, and 13C NMR techniques. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:503–506, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20153 相似文献
6.
2‐Alkylthio‐3‐amino‐4H‐imidazol‐4‐ ones 5 were synthesized by S‐alkylation of 2‐thioxo‐3‐amino‐4‐imidazolidinones 4 , which were obtained via cyclization of isothiocyanates 2 with hydrazine hydrate. 5l–n reacted with Ph3P, C2Cl6, and NEt3 to give 2H‐imidazo[2,1‐b]‐1,3,4‐thiadiazin‐ 6(7H)‐ones 7a–c in good yields. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:76–80, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20069 相似文献
7.
The reaction of 3,4‐di‐tert‐butyl‐thio‐phene 1‐oxide ( 8 ) with tetrachlorocyclopropene provided 6,7‐di‐tert‐butyl‐2,3,4,4‐tetrachloro‐8‐thia‐bicylo[3.2.1]octa‐2,6‐diene 8‐oxide ( 10 ), which was oxidized to the corresponding 8,8‐dioxide 16 by m‐chloroperbenzoic acid. The thermolysis of 16 in refluxing chlorobenzene, xylene, or octane gave 5‐tert‐ butyl‐1,2‐dichloro‐3‐[(1,1‐dich‐loro‐2,2‐dimethyl)‐pro‐ pyl]‐benzene ( 18 ) with extrusion of SO2 and 2‐tert‐butyl‐4,5,6‐trichloro‐9,9‐dimethylbicyclo[5.2.0]nona‐1,3,5‐triene ( 19 ) with extrusion of SO2 and HCl in 73–78% combined yields. On the other hand, the thermolysis of 16 in the presence of triethylamine gave 19 as the sole product in 98% yield. A mechanism that involves the initial formation of 4,5‐di‐tert‐butyl‐1,2,7,7‐tetrachlorocycloheptatriene ( 17 ) is proposed to ex‐ plain the observed products. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:132–222, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20079 相似文献
8.
Yusuf Akbaba Halis Türker Balaydın Süleyman Göksu Ertan Şahin Abdullah Menzek 《Helvetica chimica acta》2010,93(6):1127-1135
3,4‐Dibromo‐5‐[2‐bromo‐3,4‐dihydroxy‐6‐(methoxymethyl)benzyl]benzene‐1,2‐diol ( 2 ), a natural product, has been synthesized for the first time starting from (3‐bromo‐4,5‐dimethoxyphenyl)methanol ( 5 ) in five steps and with an overall yield of 34%. The reaction of some methoxymethyl‐substituted aryl methyl ethers with BBr3, followed by the addition of MeOH, afforded the corresponding methoxymethyl‐substituted arylphenols in high yields. 相似文献
9.
Irradiation (350 nm) of 2‐alkynylcyclohex‐2‐enones 1 in benzene in the presence of an excess of 2‐methylbut‐1‐en‐3‐yne ( 2 ) affords in each case a mixture of a cis‐fused 3,4,4a,5,6,8a‐hexahydronaphthalen‐1(2H)‐one 3 and a bicyclo[4.2.0]octan‐2‐one 4 (Scheme 2), the former being formed as main product via 1,6‐cyclization of the common biradical intermediate. The (parent) cyclohex‐2‐enone and other alkylcyclohex‐2‐enones 7 also give naphthalenones 8 , albeit in lower yields, the major products being bicyclo[4.2.0]octan‐2‐ones (Scheme 4). No product derived from such a 1,6‐cyclization is observed in the irradiation of 3‐alkynylcyclohex‐2‐enone 9 in the presence of 2 (Scheme 4). Irradiation of the 2‐cyano‐substituted cyclohexenone 12 under these conditions again affords only traces of naphthalenone 13 , the main product now being the substituted bicyclo[4.2.0]oct‐7‐ene 16 (Scheme 5), resulting from [2+2] cycloaddition of the acetylenic C−C bond of 2 to excited 12 . 相似文献
10.
Hafida Chemouri Sidi Mohamed Mekelleche 《International journal of quantum chemistry》2012,112(10):2294-2300
A theoretical study of the mechanism and regio‐ and stereoselectivity of Diels–Alder reactions of 5‐aryl‐2‐pyrones (Ar = Ph, 4‐(MeS)‐Ph) with substituted alkenes (CHZ = CH2, Z = COMe, OAc) is performed at the B3LYP/6‐31G(d) level. The analysis of the relevant stationary points of the potential energy surface and intrinsic reaction coordinate calculations show that these cycloadditions are undergoing through asynchronous concerted mechanisms yielding to the formation of the 5‐endo isomers as the major cycloadducts. The calculation of activation and reaction energies indicates that the 5‐endo cycloadducts are favored both kinetically and thermodynamically. The obtained results are in good agreement with experimental outcomes. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
11.
A simple and efficient method was developed for the synthesis of 1‐(substituted)‐3‐(5‐(substituted)‐1,3,4‐thiadiazol‐2‐yl) ureas from heterocyclic amino compounds and phenyl‐5‐(pyridine‐3‐yl)‐1,3,4‐thiadiazol‐2‐ylcarbamate( 2 ) or phenyl‐5‐(trifluoro‐methyl)‐1,3,4‐thiadiazol‐2‐ylcarbamate( 5 ) under solvent conditions using microwave irradiation. The products were obtained in satisfactory yield as we expected. The reactions can be realized by conventional heating, but we find that the condition of microwave is better according to the reaction time. New 1‐(substituted)‐3‐(5‐(substituted)‐1,3,4‐thiadiazol‐2‐yl) urea derivatives are reported. The products were characterized by 1H NMR, ESI‐MS, and Elemental analysis. The crystal structure of compound 6h was determined by X‐ray single crystal diffraction. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:621–629, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20489 相似文献
12.
The kinetics of liquid‐phase oxidation of 1‐methoxy‐2‐(1‐methylethyl)benzene ( 1a ), 1‐methoxy‐3‐(1‐methylethyl)benzene ( 1b ), and 1‐methoxy‐4‐(1‐methylethyl)benzene ( 1c ) with oxygen as oxidant to yield the corresponding 1‐methyl‐1‐(2‐methoxyphenyl)ethyl ( 2a ), 1‐methyl‐1‐(3‐methoxyphenyl)ethyl ( 2b ), and 1‐methyl‐1‐(4‐methoxyphenyl)ethyl ( 2c ) hydroperoxides was studied. The oxidizabilities of 1a , 1b , and 1c were established over the temperature range 50–120°C. The overall activation energies of oxidation were determined for 1b and 1c over the temperature range 50–120°C. Thermal stability of 2a and 2b and the initiating properties of hydroperoxides 2a , 2b , and 2c were studied. Long‐term noncatalytic oxidations of 1b and 1c to respective hydroperoxides were carried out. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 37: 10–16, 2005 相似文献
13.
1,3,2,4‐Dithiadiphosphetane‐2,4‐disulfide 1 reacts with substituted 2‐amino‐1,4‐naphthoquinons 2a–d to give 4,5,4′,5′‐benzodiphenoquinone‐bis‐1,3,2‐thiazaphospholine‐2‐sulfide derivatives of type 3. Compatible analytical and spectroscopic results were obtained for all the new compounds. A mechanism is proposed to explain the formation of compounds 3. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 488–491, 1999 相似文献
14.
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
15.
Dominik Albrecht Dr. Florian Vogt Thorsten Bach Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(14):4284-4296
3‐(ω′‐Alkenyl)‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones 2 – 4 were prepared as photocycloaddition precursors either by cross‐coupling from 3‐iodo‐5,6‐dihydro‐1H‐pyridin‐2‐one ( 8 ) or—more favorably—from the corresponding α‐(ω′‐alkenyl)‐substituted δ‐valerolactams 9 – 11 by a selenylation/elimination sequence (56–62 % overall yield). 3‐(ω′‐Alkenyloxy)‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones 5 and 6 were accessible in 43 and 37 % overall yield from 3‐diazopiperidin‐2‐one ( 15 ) by an α,α‐chloroselenylation reaction at the 3‐position followed by nucleophilic displacement of a chloride ion with an ω‐alkenolate and oxidative elimination of selenoxide. Upon irradiation at λ=254 nm, the precursor compounds underwent a clean intramolecular [2+2] photocycloaddition reaction. Substrates 2 and 5 , tethered by a two‐atom chain, exclusively delivered the respective crossed products 19 and 20 , and substrates 3 , 5 , and 6 , tethered by longer chains, gave the straight products 21 – 23 . The completely regio‐ and diastereoselective photocycloaddition reactions proceeded in 63–83 % yield. Irradiation in the presence of the chiral templates (?)‐ 1 and (+)‐ 31 at ?75 °C in toluene rendered the reactions enantioselective with selectivities varying between 40 and 85 % ee. Truncated template rac‐ 31 was prepared as a noranalogue of the well‐established template 1 in eight steps and 56 % yield from the Kemp triacid ( 24 ). Subsequent resolution delivered the enantiomerically pure templates (?)‐ 31 and (+)‐ 31 . The outcome of the reactions is compared to the results achieved with 4‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones and quinolones. 相似文献
16.
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
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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
17.
Vladimir A. Kozlov Irina L. Odinets Konstantin A. Lyssenko Svetlana G. Churusova Sergey V. Yarovenko Pavel V. Petrovskii Tatyana A. Mastryukova 《Heteroatom Chemistry》2005,16(2):159-168
Regioselective syntheses of novel 2‐(phosphoryl)methylidenethiazolidine‐4‐ones 3a–c, 5 by the condensation of phosphoryl acetic acid thioamides 2a–c or substituted thioanilide 4 with dimethyl acetylenedicarboxylate are described. N3‐unsubstituted thiazolidine‐4‐ones 3a–c were obtained as E,Z‐isomers, while N3‐phenyl substituted heterocycle 5 was formed as Z,Z‐isomer. The structures of thiazolidin‐4‐ones 3a ‐E,Z and 5 ‐Z,Z are characterized by crystal structure determination. According to B3Pw91/6‐31G* calculations, the isomers observed in crystals are thermodynamically preferable. In solutions, phosphorylated thiazolidines undergo isomerization (relative to C2 carbon atom of the heterocycle) proceeded by either imine–enamine (N3‐unsubstituted compounds 3a–c ) or push–pull mechanisms (N3‐substituted compound 5 ). © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:159–222, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20084 相似文献
18.
P. Vasu Govardhana Reddy Y. Hari Babu C. Suresh Reddy D. Srinivasulu 《Heteroatom Chemistry》2002,13(4):340-345
Syntheses of 2‐aryloxy/2‐chloro ethoxy‐2,3‐dihydro‐5‐benzoyl‐1H‐1,3,2‐benzodiaza‐phosphole 2‐oxides 3a–h were accomplished by reactions of equimolar quantities of 3,4‐diaminobenzophenone ( 1 ) with various aryl/chloroethoxy phosphorodichloridates 2a–g and 2h in the presence of triethylamine at 50–60°C. Compounds 3i–k were prepared by reacting 3,4‐diaminobenzophenone ( 1 ) with aryl thiophosphorodichloridates 2i–k under similar conditions. They were characterized by IR, 1H, 13C, and 31P NMR spectral data. Some of these products possessed siginificant antimicrobial activity © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:340–345, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10044 相似文献
19.
Bioreduction of 3‐substituted‐2‐oxoal‐kanephosphonates by baker's yeast afforded 3‐substituted‐2‐hydroxy‐alkanephosphonates in moderate to good yields and ee value. These compounds could serve as useful chirons for the stereoselective synthesis of phosphorus analogs of biologically active molecules including R‐(—)‐3‐trimethylammonium‐2‐hydroxypropanoic acid and R‐(—)‐3‐ trimethylammonium‐2‐hydroxypropanoic acid. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:551–556, 2001 相似文献
20.
Timothy E. Hopkins Moa Park Almary Chacon Reza Sedaghat‐Herati 《Journal of polymer science. Part A, Polymer chemistry》2005,43(9):1895-1902
Diels–Alder reactions of 5‐[methoxypoly(oxyethylene)]‐(3E)‐1,3‐pentadiene ( 1a ) with maleic anhydride, diethyl acetylenedicarboxylate (DADC), and acrolein were investigated for the synthesis of new poly(ethylene glycol) derivatives. To facilitate the characterization of the derivatives, Diels–Alder reactions of 5‐methoxyethoxy‐(3E)‐1,3‐pentadiene ( 1b ) with the aforementioned dienophiles were also studied. The reaction of o‐toluidine with the cycloaddition product from maleic anhydride and 1b resulted in the corresponding amide products. The reactions of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone with cycloadducts derived from 1a and 1b with DADC resulted in the aromatization of the corresponding products. An NMR analysis of the adducts obtained from 1a and acrolein in water and from 1b and acrolein in water/acetonitrile (4:1 v/v) indicated a mixture of endo and exo, with the endo concentration being approximately 80%. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1895–1902, 2005 相似文献