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1.
Sukanta Kamila Haribabu Ankati Emily Harry Edward R. Biehl 《Tetrahedron letters》2012,53(17):2195-2198
(Z)-5-(2-(1H-Indol-3-yl)-2-oxoethylidene)-3-(aryl/alkyl-2-ylmethyl)-2-thioxothiazolidin-4-ones (7a–w) have been synthesized by the Knoevenagel condensation reaction of 3-(aryl/alkyl-2-ylmethyl)-2-thioxothiazolidin-4-ones (3a–d) with suitably substituted 2-(1H-indol-3-yl)2-oxoacetaldehydes (6a–g) under microwave conditions. The thioxothiazolidin-4-ones were prepared from the corresponding aryl/alkyl amines (1a–d) and di-(carboxymethyl)-trithiocarbonyl (2). The aldehydes (6a–g) were synthesized from the corresponding acid chlorides (5a–g) using HsnBu3. 相似文献
2.
Alex F.C. Flores Lucas Pizzuti Darlene C. Flores Claudio M.P. Pereira 《Tetrahedron letters》2010,51(37):4908-4910
The synthesis of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrol-2(5H)-ones 5, 6a-d from 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d is reported. The 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d were obtained from regiospecific bromination of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 1, 2a-d with molecular bromine. The NMR and X-ray diffraction data showed that 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones were brominated at 4-position in the pyrrolidin-2-one ring. 相似文献
3.
《Tetrahedron: Asymmetry》2001,12(8):1201-1206
Starting from the commercially available (S)-1-phenylethylamine and l-alanine benzylester, we synthesised the homochiral N-alkenoyl aryl azides 2a–2d. The intramolecular cycloaddition of unsubstituted 2a and 2b gave enantiopure 3,3a-dihydro-1,2,3-triazolo[1,5-a][1,4]benzodiazepine-4(6H)-ones 3a, 3b, 4a and 4b, while phenyl-substituted 2c and 2d gave enantiopure 1,1a-dihydro-2H-azirino[2,1-c][1,4]benzodiazepine-4(6H)-ones 5c, 5d, 6c and 6d. 相似文献
4.
Jignesh P. Raval Hemul V. Patel Pradip S. Patel Kishor R. Desai 《Journal of Saudi Chemical Society》2010,14(4):417-421
A facile synthesis of 3-[(4-chloro-3-methylphenoxy)methyl]-6-aryl-5,6-dihydro-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 3a–n has been achieved by microwave promoted condensation of 3-mercapto-4-amino-5-[(4-chloro-3-methylphenoxy)methyl]-4H-1,2,4-triazole 1 with various aromatic aldehydes 2a–n in presence of catalytic amount of p-TsOH (para-toluenesulphonic acid). The structures of 3a–n are supported by IR and 1H and 13C NMR spectral data. 相似文献
5.
Synthesis, characterization, and applications in Heck and Suzuki coupling reactions of amphiphilic cyclopalladated ferrocenylimines 总被引:1,自引:0,他引:1
Bing Mu Tiesheng Li Wenjian Xu Guoliang Zeng Pingping Liu Yangjie Wu 《Tetrahedron》2007,63(46):11475-11488
A series of novel amphiphilic ferrocenylimines and their cyclopalladated complexes of general formula [Fe(η5-C5H5)(η5-C5H4CR1NR2)] (R1=H, R2=C12H25-n4a, R1=H, R2=C16H33-n4b, R1=CH3, R2=C12H25-n4c, R1=CH3, R2=C16H33-n4d), [PdCl{[(η5-C5H5)]Fe[(η5-C5H3)CR1NR2]}]2 (5a-d), [PdCl{[(η5-C5H5)]Fe[(η5-C5H3)-CR1NR2]}(PPh3)] (6a-d), were prepared and characterized by 1H NMR, 13C NMR, 31P NMR, IR, HRMS, and elemental analysis. The crystal structures of 5c,d were determined by X-ray crystallography. These amphiphilic cyclopalladated complexes are thermally stable and insensitive to oxygen and moisture. The redox properties of 4a-d, 5a-d, 6a-d were also investigated using cyclic voltammetric technique. Compounds 5a-d, 6a-d displayed good activity in the Heck reaction of a variety of aryl halides with ethyl acrylate or styrene and the Suzuki-Miyaura cross-coupling reaction of aryl bromides with phenylboronic acid in bulk solution. They are also suitable for formation of Langmuir-Blodgett (LB) films. 相似文献
6.
《Journal of molecular catalysis. A, Chemical》1998,128(1-3):85-102
The (conjugated diene) group 4 metallocenes 1a–d (diene=butadiene, isoprene; metallocene=Cp2Zr, Cp2Hf, MeCp2Zr) add B(C6F5)3 to yield the metallacyclic M⋯F–C bridged metallocene–borate–betaine complexes 3a–d. These add one equivalent of acetylene to give the chiral metallacyclic insertion products 5a–d that can be described as either intramolecular ion-pair type complexes involving interaction of the negatively polarized terminal –CHCH–CH2–[B] group of the resulting σ-ligand system with the positively polarized metallocene moiety of the dipolar betaine product or η2-internal alkene metallocene complexes, respectively, as it is revealed by a comparison with the related acyclic THF-addition products 10 and 12. Propyne inserts unselectively into the terminal Zr–C bond of the complexes 3a–c. In each case a 1:1 mixture of the regioisomers 6a–c (methyl at C2) and 7a–c (methyl group at C1) is obtained. 相似文献
7.
Sixteen new chiral alcohols with alkyl (C11–C19) and aryl, substituted aryl, hetero aryl and biaryl groups 2a–2t were synthesized by three different asymmetric reduction methods from their corresponding ketones 1a–1t. Chiral NaBH4 (method A), chiral BH3 (method B) and chiral AIP (method C) were used as asymmetric reduction catalysts. Chiral NaBH4 was modified by four different ligands 3a–3d, chiral BH3 and chiral AIP by four different ligands 4a–4d. Ligand 4c was synthesized for the first time in this work. Chiral NaBH4 generated chiral alcohols of (R)-configuration and chiral BH3 and chiral AIP of (S)-configuration with high enantiomeric excesses, were analysed by chiral HPLC. In order to determine the ee values by chiral HPLC, sixteen corresponding racemic alcohols, synthesized by reducing their corresponding ketones via NaBH4, were used for chiral resolution on a Daicel OD HPLC column. The sixteen starting ketones were synthesized in this study by Friedel–Craft acylation. The new chiral alcohols were characterized by IR, NMR, (1H and 13C), MS, elemental analyses and specific rotation. The reduction methods A, B and C were applied to these ketones for the first time in this study and were compared with each other. The relationship between the structure of the ketone and the yield and the enantiomeric excess was discussed. 相似文献
8.
《Journal of organometallic chemistry》2005,690(24-25):5867-5875
In order to probe the ligand properties we have examined a series of Cr(CO)5L and Ni(CO)3L complexes using density functional theory (DFT). The ligands included in our study are N-heterocyclic carbenes (NHCs) and Bertrand-type carbenes. Our study shows that the carbene–metal bonds of imidazol-2-ylidenes (1), imidazolin-2-ylidenes (2), thiazo-2-ylidenes (3), and triazo-5-ylidenes (4) are significantly stronger than those of Bertrand-type carbenes (5–7). The force constants of C–O in complexes are related to the property of isolated carbenes such as proton affinity (PA), electronegativity (χ), and charge transfer (ΔN). NHCs and Bertrand-type carbenes are identified as nucleophilic, soft ligands. Carbene stabilization energy (CSE) computations indicate that carbenes 1 and 4 are the most stable species, while 2 and 3 are less stable. In contrast to NHCs, CSE of carbenes 5–7 are much smaller, and their relative stabilities are in the order (amino)(aryl) carbenes 7e–7g > (amino)(alkyl) carbenes 7a–7d > (phosphino)(aryl) 6d–6e, and (phosphino)(silyl) carbenes 5a–5c > (phosphino)(alkyl) carbenes 6a–6c. 相似文献
9.
Gannerla Saidachary Kasagani Veera PrasadMudulkar Sairam Bhimapaka China Raju 《Tetrahedron letters》2014
A facile method has been developed for the synthesis of 4H-chromene-3-carboxylates 3a–d by the nucleophilic substitution reaction of 2-hydroxy-2H-chromene-3-carboxylates 2a–d with triethylsilane in the presence of BF3·O(C2H5)2. Cyclocondensation of 4H-chromene-3-carboxylates 3a–d with benzylamines 4a–d afforded a series of 2,3-dihydrochromenopyrrolones 5a–p and with propargylamine afforded 2-propynyl-2,3-dihydrochromenopyrrolones 6a–d. Click reaction of 6a–d with benzyl azides 7a–d provided a series of 1H-1,2,3-triazolylmethyl-2,3-dihydrochromenopyrrolones 8a–p. Thus synthesized compounds 3a–d, 5a–p, 6a–d, and 8a–p are novel heterocyclic compounds and being reported for the first time. 相似文献
10.
《Tetrahedron: Asymmetry》2003,14(7):787-790
A series of racemic dirhodium(II) compounds with two ortho-metalated aryl phosphine ligands in a head-to-tail arrangement Rh2(O2CR)2(pc)2 (pc=ortho-metalated aryl phosphine) (1a–k) were tested in the regio- and stereoselective cyclopropanation of racemic 1-diazo-6-methyl-3-(2-propenyl)-5-hepten-2-one 2, which possesses two different reactive CC double bonds for a five-membered-ring formation. The complexes Rh2(O2CCH3)2(pc)2 {pc=[(C6H4)P(C6H5)2], [(p-CH3C6H3)P(p-CH3C6H4)2], and [(C6H4)P(C6H5)(C6F5)]} (1a–d) successfully enhanced the cyclopropanation of trisubstituted versus monosubstituted CC bonds to give an 80:20 selectivity ratio. The reaction occurred with excellent diastereoselectivity; the syn-products were the only stereoisomers observed in the whole series of the catalysts. Enantioenriched products were obtained when enantiomerically pure dirhodium(II) complexes were used. 相似文献
11.
Aline Maisse-François Laurine Azor Anne-Laure Schmitt Ariane Coquel Lydia Brelot Richard Welter Stéphane Bellemin-Laponnaz Samuel Dagorne 《Journal of organometallic chemistry》2012,696(26):4248-4256
The present contribution describes the synthesis and structural characterization of structurally diverse organoaluminum species supported by variously substituted aminophenolate-type ligands: these Al complexes are all derived from the reaction of AlMe3 with aminophenols 2-CH2NH(R)-C6H3OH (1a, R = mesityl (Mes); 1b, R = 2,6-di-isopropylphenyl (Diip)) and 2-CH2NH(R)-4,6-tBu2-C6H2OH (1c, R = Mes; 1d, R = Diip). The low temperature reaction of AlMe3 with 1a–b readily affords the corresponding Al dimeric species [μ-η1,η1-N,O-{2-CH2NH(R)-C6H4O}]2Al2Me4 (2a–b), consisting of twelve-membered ring aluminacycles with two μ-η1,η1-N,O-aminophenolate units, as determined by X-ray crystallographic studies. Heating a toluene solution of 2a (80 °C, 3 h) affords the quantitative and direct formation of the dinuclear aluminium complex Al[η2-N; μ,η2-O-{2-CH2N(Mes)-C6H4O}](AlMe2) (4a) while species 2b, under the aforementioned conditions, affords the formation of the Al dimeric species [η2-N,O-{2-CH2N(Dipp)-C6H4O}AlMe]2 (3b), as deduced from X-ray crystallography for both 3b and 4a. In contrast, the reaction of bulky aminophenol pro-ligands 1c–d with AlMe3 afford the corresponding monomeric Al aminophenolate chelate complexes η2-N,O-{2-CH2NH(R)-4,6-tBu2-C6H2O}AlMe2 (5c–d; R = Mes, Diip; Scheme 3) as confirmed by X-ray crystallographic analysis in the case of 5d. Subsequent heating of species 5c–d yields, via a methane elimination route, the corresponding Al-THF amido species η2-N,O-{2-CH2N(R)-4,6-tBu2-C6H2O}Al(Me)(THF) (6c–d; R = Mes, Diip). Compounds 6c–6d, which are of the type {X2}Al(R)(L) (L labile), may well be useful as novel well-defined Lewis acid species of potential use for various chemical transformations. Overall, the sterics of the aminophenol backbone and, to a lesser extent, the reaction conditions that are used for a given ligand/AlMe3 set essentially govern the rather diverse “structural” outcome in these reactions, with a preference toward the formation of mononuclear Al species (i.e. species 5c–d and 6c–d) as the steric demand of the chelating N,O-ligand increases. 相似文献
12.
《Journal of organometallic chemistry》1989,363(3):C36-C40
Reaction of the ferriochlorosilanes R5C5(CO)2FeSiR′3-nCln (1a–1f) with sodium azide in tetrahydrofuran yields the ferrio- (mono-, bis-, and tris-azido)silanes R5C5(CO)2FeSiR′3-n(N3)n (R = H, Me; R′ = Me, H; n = 1–3) (2a–2f). CCl4 converts Cp(CO)2FeSiMe(H)N3 (2a) into the ferrioazido(chloro)silane Cp(CO)2-FeSiMe(Cl)N3 (3). Treatment of 2d, 2f with Me3P results in the formation of the ferriosilyl-iminophosphoranes Cp(CO)2FeSi(N3)(R)NPMe3 (R = Me, N3), (4a, 4b) by N2 elimination. 相似文献
13.
《Journal of organometallic chemistry》2011,696(26):4248-4256
The present contribution describes the synthesis and structural characterization of structurally diverse organoaluminum species supported by variously substituted aminophenolate-type ligands: these Al complexes are all derived from the reaction of AlMe3 with aminophenols 2-CH2NH(R)-C6H3OH (1a, R = mesityl (Mes); 1b, R = 2,6-di-isopropylphenyl (Diip)) and 2-CH2NH(R)-4,6-tBu2-C6H2OH (1c, R = Mes; 1d, R = Diip). The low temperature reaction of AlMe3 with 1a–b readily affords the corresponding Al dimeric species [μ-η1,η1-N,O-{2-CH2NH(R)-C6H4O}]2Al2Me4 (2a–b), consisting of twelve-membered ring aluminacycles with two μ-η1,η1-N,O-aminophenolate units, as determined by X-ray crystallographic studies. Heating a toluene solution of 2a (80 °C, 3 h) affords the quantitative and direct formation of the dinuclear aluminium complex Al[η2-N; μ,η2-O-{2-CH2N(Mes)-C6H4O}](AlMe2) (4a) while species 2b, under the aforementioned conditions, affords the formation of the Al dimeric species [η2-N,O-{2-CH2N(Dipp)-C6H4O}AlMe]2 (3b), as deduced from X-ray crystallography for both 3b and 4a. In contrast, the reaction of bulky aminophenol pro-ligands 1c–d with AlMe3 afford the corresponding monomeric Al aminophenolate chelate complexes η2-N,O-{2-CH2NH(R)-4,6-tBu2-C6H2O}AlMe2 (5c–d; R = Mes, Diip; Scheme 3) as confirmed by X-ray crystallographic analysis in the case of 5d. Subsequent heating of species 5c–d yields, via a methane elimination route, the corresponding Al-THF amido species η2-N,O-{2-CH2N(R)-4,6-tBu2-C6H2O}Al(Me)(THF) (6c–d; R = Mes, Diip). Compounds 6c–6d, which are of the type {X2}Al(R)(L) (L labile), may well be useful as novel well-defined Lewis acid species of potential use for various chemical transformations. Overall, the sterics of the aminophenol backbone and, to a lesser extent, the reaction conditions that are used for a given ligand/AlMe3 set essentially govern the rather diverse “structural” outcome in these reactions, with a preference toward the formation of mononuclear Al species (i.e. species 5c–d and 6c–d) as the steric demand of the chelating N,O-ligand increases. 相似文献
14.
Gyula Simig Gábor Doleschall Gyula Hornyák József Fetter Károly Lempert József Nyitrai Péter Huszthy Tibor Gizur Mária Kajtár-Peredy 《Tetrahedron》1985,41(2):479-484
Acylation of the N-substituted diethyl aminomalonates 3a–3d with diketene furnished the ring tautomers 6a–6d of the expected acetoacetyl derivatives 5. By treatment with iodine and sodium ethoxide compounds 6a–6d are smoothly converted into the β-lactam derivatives 2a–2d. Deethoxycarbonylation of the ethylene ketals 7a–7d of the latter furnishes mixtures of the corresponding diastereomeric monoesters 8 and10. The ethoxycarbonyl groups of the trans esters 8 are more reactive than those of the cis isomers 10. This permits, under appropriate conditions, selective alkaline hydrolysis and NaBH4 reduction of the trans esters 8 in the presence of the cis esters 10. Reduction of the cis ester 10c under more forceful conditions furnishes the trans hydroxymethyl derivative 11c. 相似文献
15.
Hidenori Hanaoka 《Journal of organometallic chemistry》2006,691(23):4968-4974
Phosphorous-bridged bisphenoxy titanium complexes were synthesized and their ethylene polymerization behavior was investigated. Bis[3-tert-butyl-5-methyl-2-phenoxy](phenyl)phosphine tetrahydrofuran titanium dichloride (4a) was obtained by treatment of 3 equiv of n-BuLi with bis[3-tert-butyl-2-hydroxy-5-methylphenyl](phenyl)phosphine hydrochloride salt (3a) followed by TiCl4(THF)2 in THF. THF-free complexes 5a-5d were synthesized more conveniently by the direct reaction of MOM-protected ligands (2a-2d) with TiCl4 in toluene. X-ray analysis of 4a revealed that the ligand is bonded to the octahedral titanium (IV) center in a facial fashion and two chlorine atoms possess cis-geometry. Complexes 4a and 5a-5d were utilized as catalyst precursors for ethylene polymerization. Complex 5c gave high molecular weight polyethylene (Mw = 1,170,000, Mw/Mn = 2.0) upon activation with Al(iBu)3/[Ph3C][B(C6F5)4] (TB). Ethylene polymerization activity of 5d activated with Al(iBu)3/TB reached 49.0 × 106 g mol (cat) −1 h−1. 相似文献
16.
Thermal decomposition of N(phenylsulfonyl)-benzohydrazonoyl chloride (1) in refluxing toluene generated N-phenylsulfonylbenzonitrilimine (2) which gave 1,3-dipolar cycloadducts with ethyl (4a) and methyl acrylate (4b), acrylonitrile (4c), styrene (4d), norbornene (4e), and norbornadiene (4f). The reactions with 4a–d, 2 afforded regiospecifically 5-R substituted pyrazolines 5a–d in lower yields. The raction of 2 with 4e gave only exo adduct 5e, while the reaction with 4f gave both exo- (5fx) and endo adducts (5fn) as well as their retro-Diels-Alder product 6. 相似文献
17.
Saya Kawano Yutaka Yoshikawa Akihiro Kato Shoko Higashi Kyohei Mitani Hiroyuki Yasui Yoichi Habata Shunsuke Kuwahara Kaname Sasaki Ryota Saito 《Tetrahedron letters》2019,60(23):1534-1537
We have developed a synthetic route to novel ethyl 1-arylmethyl-5-oxo-2-thioxopyrrolidine-3-carboxylates (1a–e) via an unprecedented reaction of ethyl 1-arylmethyl-4-acetoxy-5-oxo-2,5-dihydro-1H-pyrrole-3carboxylates with potassium thioacetate. Synthesized products 1a–e were further converted into their zinc(II) complexes (10a–e), having an S2O2-type coordination mode, that showed improved insulin-mimetic activities compared to ZnSO4, a positive standard, and also the previously reported zinc(II) complexes of ethyl 1-benzyl-4-hydroxy-5-oxo-2,5-dihydro-1H-pyrrole-3-carboxylates with O4-type coordination mode. 相似文献
18.
《Polyhedron》1999,18(23):3057-3064
The synthesis of new cyclometalated compounds of palladium(II) with the mixed-donor bidentate ligands o-Ph2PC6H4–CH=NR is described. Two series of complexes [Pd(C^N)(o-Ph2PC6H4–CH=NR)][PF6] have been prepared using either azobenzene or 2-phenylpyridine as cyclometalated ligands [C^N=azobenzene (azb); R=Me (1a), Et (2a), nPr (3a), iPr (4a), tBu (5a), Ph (6a), NH–Me (7a); C^N=2-phenylpyridine (phpy); R=Me (1b), Et (2b), nPr (3b), iPr (4b), tBu (5b), Ph (6b), NH–Me (7b)]. The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, FAB, 1H and 31P NMR). The molecular structures of compounds 2a (monoclinic, P 21/n) and 1b (monoclinic, C 2/c) have been determined by a single-crystal diffraction study. In both cases this technique revealed the relative trans configuration between the phosphorus atom and the nitrogen atom of the ortho-metalated ligand. 相似文献
19.
Treatment of endo-2 or exo-2-hydroxy-1-substituted ketals 1a–d with p-toluensulfonic acid in dry benzene results in a reversible C9 bridge cleavage and affords equilibrium mixtures where 2-substituted-6-(1,3-dioxolan-2-yl)cyclooctanones 6a–d are present as main products. Yields in 6a–d are present as the steric hindrance of the substituents at C1 in the substrate increases as well. Deuterium exchange experiments are in favour of an intramolecular 1,3-hydride shift from C2 to C9. 相似文献
20.
The carbosilanes RMe2Si(CH2)xSiH3, [R = 2-Th (1a, 2a), 4-Me-2-Th (3a, 4a), 2-Fu (5a, 6a), 5-Me-2-Fu (7a, 8a); x = 2 and 3], with primary SiH3 end groups undergo a facile dehydropolymerization under ambient conditions (50 °C, 48 h) in presence of Cp2TiCl2/2.2 n-BuLi catalyst to afford the corresponding poly(hydrosilane)s 1–8 bearing carbosilyl side chains appended with thienyl/furyl groups. These have been characterized by GPC, IR, multinuclear (1H, 13C{1H}, 29Si{1H}) NMR, UV and PL spectral studies. 相似文献