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1.
Euchrenone a2 (7) isolated from the roots ofEuchresta japonica has been synthesised from 3-prenylphloroacetophenone (1) by other workers. We carried out its cyclodehydrogenation with dichloro dicyano quinone (DDQ) to obtain 6-acetyl-5,7-dihydroxy-2,2-dimethylchromene
(2) which was ethoxymethylated in the 7-position to give 6-acetyl-7-ethoxymethoxy-5-hydroxychromene (3). Chalcone condensation of3 and 4-ethoxymethoxy-3-C-prenylbenzaldehyde (4) gave 4,6′-bisethoxymethoxy-2′-hydroxy-6″, 6″-dimethyl-3-C-prenylpyrano (2″, 3″–4,3) chalcone (5) which cyclised with methanolic sodium acetate to give protected 5,4′-bisethoxymethoxy-6″, 6″-dimethyl-3′-C-prenylpyrano (2″, 3″–7,8) flavanone (6). Deprotection of6 with 4% methanolic HCl yielded (7) with melting point and spectral data identical to that of the natural compound. 相似文献
2.
M. Patt M. Kuntzsch H. -J. Machulla 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(3):925-927
The dependence of the radiochemical yield of [18F]fluoromisonidazole (1) on different reaction parameters such as reaction time, temperature and amount of precursor was investigated for the nucleophilic
substitution of tosylate by [18F]fluoride and subsequent hydrolysis of the protecting group on 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulfonylpropanediol
as the precursor molecule (2). Highest yields (86%±6%) were obtained using 10 mg (2) at 100°C for 10 minutes, whereas both at 80 and 120°C the yields were lower (46%±11% and 29%±14%, respectively). A rapid
decrease of the yield was observed when the reaction time exceeded 15 minutes, i.e., at 100°C using 5 mg (2) the radiochemical yield decreased from 61%±8% at 15 minutes to 18%±10% at 60 minutes. 相似文献
3.
Sushanta Saha Prodyut Kumar Sarkar Ambikesh Mahapatra 《Transition Metal Chemistry》2006,31(3):389-395
The reaction between Pd(N,N′)Cl2 [N,N′ ≡ 1-alkyl-2-(arylazo)imidazole (N,N′) and picolinic acid (picH) have been studied spectrophotometrically at λ = 463 nm in MeCN at 298 K. The product is [Pd(pic)2] which has been verified by the synthesis of the pure compound from Na2[PdCl4] and picH. The kinetics of the nucleophilic substitution reaction have been studied under pseudo-first-order conditions.
The reaction proceeds in a two-step-consecutive manner (A → B → C); each step follows first order kinetics with respect to
each complex and picH where the rate equations are: Rate 1 = {k′0 + k′2[picH]0} × [Pd(N,N′)Cl2] and Rate 2 = {k′′0 + k′′2[picH]0}[Pd(N,O)(monodentate N,N′)Cl2] such that the first step second order rate constant (k′2) is greater than the second step second order rate constant (k′′2). External addition of Cl− (as LiCl) suppresses the rate. Increase in π-acidity of the N,N′ ligand, increases the rate. The reaction has been studied
at different temperatures and the activation parameters (Δ‡H° and Δ‡S°) were calculated from the Eyring plot. 相似文献
4.
Zusammenfassung Die mit 2-Cyano-2-propylradikalen aus AIBN ausgel?ste und beendete intramolekulare Cycloaddition von 2,6-Bis(2-methacryloyloxy-5-methylbenzyl)-4-methylphenylmethacrylat
(1) gibt die Cycloaddukte 4-Methyl-1,2,6-benzoltriyl-2,6-bis(4-methyl-2-methy-len-1,2-phenylen)-2,9-dicyano-2,3,5,7,9-pentamethyl-3,
5,7-dekantricarboxylat (1a) und -2,9-dicyano-2,3,5,8,9-pentamethyl-3,5,8-dekantricarboxylat (1b), welche molekulareinheitliche Leiteroligpmere vorstellen. Daneben bildeten sich 10-(2-Cyano-2-methylpropyl)8-(2-cyano-2-propyl)-4-
{2-[(2-cyano-2-methylpropyl) acryloyloxy]-5-methylbenzyl∼-2,8,10,15-tetramethyl-7, 11-dioxo-dibenzo[b,e]-1,7-dioxacyclododekan-2,5-dien
(1c) und 6 {2-[4-Cyano-2-(2-cyano-2-propyl)-2,4-dimethylvaleryloxy]-5-methylbenzyl}-4,4′-dimethyl-2,2′-methylendiphenyl-bis[2-(2-cyano-2-methylpropyl)
acrylat] (1d). Bezogen auf den Ausgangsester1 konnten insgesamt 92% getrennte und dünnschicht-chromatographisch reine Reaktionsprodukte gefa?t werden. Die den Verbindungen
zugeordneten Strukturen wurden mittels IR- und UV-Spektren sowie1H-NMR- und massenspektrometrische Analyse gesichert. Die Cycloaddukte1a und1b sind Produkte einer synthetischen Matrizenreaktion(7), deren Ergebnisse an anderer Stelle mitgeteilt werden soll.
Mit 3 Abbildungen und 5 Tabellen 相似文献
Summary The intramolecular cycloaddition of 2,6-bis(2-methacryloyloxy-5-methylbenzyl)-4-methylphenyl-methacrylate (1) was started and terminated by 2-cyano-2-propyl radicals from azoisobutyronitrile. The cycloadducts are 4-methyl-1,2,6-benzoltriyl-2,6-bis (4-methyl-2-methylene-1,2-phenylene)-2,9-dicyano-2,3, 5,7,9-pentamethyl-3,5,7-decanetricarboxylate (1a) and-2,9-dicyano-2,3,5,8,9-pentamethyl-3,5,8-decanetricarboxylate (1b), which are also molecularly uniform ladder oligomers. The side products are e]-1,7-dioxacyclododecane-2,5-diene (1c) and 6{2-[4-cyano-2-(2-cyano-2-propyl)-2,4-dimethylvaleryloxy]-5-methylbenzyl∼-4,4′-dimethyl-2,2′-methylenediphenyl-bis[2-(2-cyano-2 methylpropyl)acrylate] (1d). All together and relative to the starting ester1 92 % thin layer chromatographically pure reaction products could be isolated. The suggested structures of the compounds were confirmed by infrared and ultraviolet spectra as well as by1H-NMR and mass spectroscopical analysis. The cycloadducts1a and1b are compounds of a matrix reaction (7). Their results will be published elsewhere.
Mit 3 Abbildungen und 5 Tabellen 相似文献
5.
Seikh Jasimuddin 《Transition Metal Chemistry》2006,31(6):724-729
Dechlorination of M(RaaiR′)
n
Cl2 by AgNO3 produced [M(RaaiR′)
n
(MeCN)2]+2 [M = Ru(II), n = 2; Pt(II), n = 1; RaaiR′ = 1-alkyl-2-(arylazo)imidazole)] which upon reaction with the nucleobase cytosine (C) in MeCN solution gave cytosinato
bridged dimeric compounds which were isolated as perchlorate salts [M2(RaaiR′)
n
(C)2](ClO4)2 · H2O. The products were characterized by IR, u.v.–vis., 1H-n.m.r. spectroscopy and cyclic voltammetry. In MeCN solution the ruthenium complexes exhibit a strong MLCT band at 550–555 nm
and two redox couples positive to SCE due to two metal-center oxidation along with ligand reduction, negative to SCE. The
platinum complexes show a weak transition at 500–520 nm in MeCN and exhibit only ligand reduction in cyclic voltammetry. The
coordination of the ligand was supported by 1H-n.m.r. spectral data. 相似文献
6.
A. V. Timshina S. A. Rubtsova I. N. Alekseev P. A. Slepukhin A. V. Kuchin 《Russian Journal of Organic Chemistry》2010,46(3):363-367
(1R,1′R,2S,4R)-1,7,7-Trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′-oxide, (1R,2S,3′R,4R)-1,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′,1′,3′-trioxide, and (1R,4R)-1,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′,1′,3′,3′-tetraoxide were synthesized by oxidation of
camphor ethylene dithioacetal with m-chloroperoxybenzoic acid at different substrate-tooxidant ratios. The structure of the products was proved by IR and NMR
spectroscopy and X-ray analysis. 相似文献
7.
Lutz Preu Wolfgang Kliegel Steven J. Rettig James Trotter 《Monatshefte für Chemie / Chemical Monthly》2001,132(10):1213-1224
Summary. The structure of the dehydrogenation product 1′,3a′-dihydro-3′-((1,3-dioxoindan-2-ylidene)-phenyl-methyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′-(5′H, 6a′H)-tetrone derived from the cycloadducts (±)-(3a′S,6a′R)-1′,3a′-dihydro-3′-((R)-α-(1,3-dioxoindanyl)-benzyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′(5H,6a′H)-tetrone and/or (±)-(3a′S,6a′R)-1′,3a′-dihydro-3′-((S)-α-(1,3-dioxoindanyl)-benzyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′(5H,6a′H)-tetrone, which were synthesized by 1,3-dipolar cycloaddition of N-phenylmaleimide to 2-((2-(1,3-dioxoindan-2-yl)-2-phenyl-ethenyl)-imino)-indan-1,3-dione,
was determined by X-ray analysis. Crystal data (CCD, 180 K): rhombohedral, R&3macr;;, a = 34.0871(7), c = 13.9358(5) ?, Z = 18; the structure was solved by direct methods and refined by full-matrix least-squares procedures to R(F, I ≥ 3σ(I)) = 0.053. The molecule contains a central folded ring system of two cis-fused 5-membered heterocyclic rings; each ring is nearly planar, and the angle between the rings amounts to 59.0°. Dynamic
1H NMR spectroscopy of the product revealed an exchange process caused by restricted rotation of the double bonded 1,3-indandione
moiety and the phenyl group about the Csp2-Csp2 single-bonds. Molecular modeling and complete lineshape analysis indicated a four site exchange process for which free energies
of activation and free energies could be established. ΔG
‡ values for the barriers of rotation are in the range of 57–59 kJ · mol − 1 at 273 K, which is unusually high for an unsubstituted phenyl group.
Received May 3, 2001. Accepted (revised) June 8, 2001 相似文献
8.
Prithwiraj Byabartta 《Transition Metal Chemistry》2005,30(8):978-986
The reaction of ctc-[Ru(RaaiR′)2Cl2] (3a–3i) [RaaiR′=1-alkyl-2-(arylazo)imidazole, p-R—C6H4—N=N— C3H2NN(1)—R′, R=H, OMe, NO2, R′=Me, Et, Bz] with KS2COR′′ (R′′=Me, Et, Pr, Bu or CH2Ph) in boiling dimethylformamide afforded [RuII{o-S—C6H4(p-R-)—N=N—C3H2NN(1)—R′}2] (4a–4i), where the ortho-carbon atom of the pendant phenyl ring of both ligands has been selectively and directedly thiolated. The newly formed tridentate
thiolate ligands are bound in a meridional fashion. The solution electronic spectra exhibit a strong MLCT band near 700 nm
and near 550 nm, respectively in DCM. The molecular geometry of the complexes in solution has been determined by H n.m.r.
spectroscopy. Cyclic voltammograms show a Ru(II)/Ru(III) couple near 0.4 V and an irreversible oxidation response near 1.0
V due to oxidation of the coordinated thiol group, along with two successive reversible ligand reductions in the range −0.80–0.87
V (one electron), −1.38–1.42 V (one electron). Coulometric oxidation of the complexes at 0.6 V versus SCE in CH2Cl2 produced an unstable Ru(III) congener. When R=Me the presence of trivalent ruthenium was proved by a rhombic e.p.r. spectrum
having g1=2.349, g2=2.310. 相似文献
9.
T. I. Kulak O. V. Tkachenko O. Yu. Grishan T. A. Kukharskaya L. A. Eroshevskaya E. N. Kalinichenko A. I. Zinchenko 《Chemistry of Natural Compounds》2009,45(1):74-78
A method for chemico-enzymatic synthesis of (2′-5′)-oligonucleotides with 6-N-benzylaminopurineriboside as the nucleoside units was proposed. The method consisted of enzymatic hydrolysis of the oligonucleotides
with mixed (2′-5′)-(3′-5′)-phosphodiesterbonds that were prepared by polymerization of 6-N-benzyladenosine-2′(3′)-monophosphate by using (3′-5′)-specific nuclease and phosphatase contained in the filtrate of culture
medium of the mycelial fungus Spicaria violacea.
Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 64–68, January–February, 2009. 相似文献
10.
6-Methyl-6-hepten-2-one (3) on reaction with ethyl α-dimethylphosphonate/NaH gives a mixture of (E)-and (Z)-conjugated esters. The major (E)-isomer, (E)-ethyl-3,7-dimethyl-2,7-octadienoate (4), on reduction with LiAlH4 at room temperature furnishes (E)-3,7-dimethyl-2,7-octadien-l-ol (5) which on propionylation affords (E)-3,7-dimethyl-2,7-octadienyl propionate (1). Carbinol (5) is converted into its silyl ether (E)-2,6-dimethyl-8-t-butyldimethylsilyloxy-l,6-octadiene (6) witht-Bu(Me)2SiCl in CH2Cl2, which on hydroboronation-oxidation with 9-BBN/NaOH-H2O2 followed by disilylalion with (n-Bu)4N+ F− at room temperature, gives (E)-3,7-dimethyl-2-octen-l,8-diol (2). 相似文献
11.
Nucleophilic substitution of Pd(RaaiR′)Cl2 [(RaaiR′ = 1-alkyl-2-(arylazo)imidazole, p-R-C6H4-N=N-C3H2NN-1-R′; where R = H(a)/ Me(b)/ Cl(c) and R′ = Et(1)/Bz(2)] with 2-Mercaptopyridine (2-SH-Py) in acetonitrile (MeCN) at 298 K, to form [Pd2(2-S-Py)4], has been studied spectrophotometrically under pseudo-first-order conditions and the analyses support the nucleophilic association
path. The reaction follows the rate law, Rate = {k
0 + k [2-SH-Py]
0
2
}[Pd(RaaiR′)Cl2]: first order in Pd(RaaiR′)Cl2 and second order in 2-SH-Py. The rate of the reaction follows the order: Pd(RaaiEt)Cl2
(1) < Pd(RaaiBz)Cl2
(2) and Pd(MeaaiR′)Cl2 (b) < Pd(HaaiR′)Cl2 (a) < Pd(ClaaiR′)Cl2 (c). External addition of Cl− (LiCl) and HCl suppresses the rate (Rate ∝ 1/[Cl−]0 & ∝1/[HCl]0). The reactions have been studied at different temperatures (293–308 K) and activation parameters (Δ‡ H° and Δ ‡ S°) of the reactions were calculated from the Eyring plot and support the proposed mechanism. 相似文献
12.
Complexes [Pd(bt)(4,4′-bpy)OOCCH3], [Pd(bt)NO3]2(m-4,4′-bpy), [Pd(bt)(m-4,4′-bpy)]4(NO3)4 (bt− is deprotonated form of 2-phenylbenzothiazole, bpy is 4,4′-bipyridyl) are prepared and characterized by 1H NMR, electron absorption and emission spectroscopy, as well as by voltammetry. The upfield shift of the signal of proton
in the ortho-position to the donor carbon atom of the cyclopalladated ligand in the complexes [(Δδ = −(1.1–1.5) ppm] is assigned to the
anisotropic effect of the ring current of the pyridine rings of the 4,4′-bipyridyl moiety, which are orthogonal to the coordination
plane. Characteristic longwave absorption bands λ = (387±4) nm and the low-temperature phosphorescence bands λ = (512±3) nm
in the complexes are assigned to the chromophore {Pd(bt)} metal complex fragment. The reduction waves in the complexes [E
1/2 = −(1.54±0.04) and E
p = −(1.83±0.03) V] are assigned to the ligand-centered processes of the successive electron transfer to the π* orbitals localized
predominantly on the coordinated pyridine components of the 4,4′-bipyridyl moiety. 相似文献
13.
Two polypyridyl ligands, 5-(4′-ethynylbenzo-15-crown-5)-2,2′-bipyridine (L1) and 3-bromo-8-(4′-ethynylbenzo-15-crown-5)-1,10-phenanthroline (L2), and their Ru(II) complexes [(bpy)2RuL](PF6)2 have been prepared and characterized. Both complexes exhibit metal-to-ligand charge transfer absorption at around 452 nm
and emission at around 640 nm in MeCN solution. Electrochemical studies of the complexes reveal a Ru(II)-centered oxidation
at around 1.31 V and three ligand-centered reductions. The binding ability of the complexes with Na+ has been investigated by UV/Vis absorption, emission, and electrochemical titrations. Addition of Na+ to MeCN solutions of both complexes results in a progressive enhancement of the emission, a red-shift of the UV/Vis absorption,
and a progressive cathodic shift of the Ru(II)-centered E
1/2 couple. The stability constants for the 1:1 stoichiometry adducts of the complexes with Na+ have been obtained from the UV/Vis absorption titrations. 相似文献
14.
Sanjay Senapoti Kamal Krishna Sarker Tapan Kumar Mondal Chittaranjan Sinha 《Transition Metal Chemistry》2006,31(3):293-298
2-(Methyl)-4-(arylazo)imidazole (RLH) (1, 2) are new series of azoimidazoles. Upon treatment of alkylhalide in dry THF in presence of NaH has synthesised 1-alkyl-2-(methyl)-4-(arylazo)imidazole
(RLR′) (3, 4). They belong to the azoimine family of N,N′-chelating ligand. They stabilize the Cu(I) oxidation state and we have synthesized [Cu(RLR′)2](ClO4) (5, 6). These complexes show a moderately intense visible band (500–600 nm) which has been assigned to 3d(Cu) → π*(ligand) transition. Ag(I) complexes of RLR′ (7, 8) are also very stable under ambient conditions and show weak transitions in the visible region. The Cu(I)-complexes show high
potential Cu(II)/Cu(I) redox couple > 0.4 V vs Ag, AgCl/Cl− reference electrode. All these complexes have been structurally characterized by 1H NMR spectroscopic data. 相似文献
15.
Ning Ma Wen-Ying Liu Huan-De Li Xin-Yu Jiang Bi-Kui Zhang Rong-Hua Zhu Feng Wang Wei Liu Xia Liu Da-Xiong Xiang 《Chromatographia》2007,66(3-4):251-255
(E)-3,5,4′-trimethoxystilbene (BTM-0512) is a resveratrol analog with a variety of pharmacological action, including anti-cancer
properties, anti-allergic activity, estrogenic activity, antiangiogenic activity, and vascular-targeting activity against
microtubule-destabilization. There is, however, no validated analytical method for quantification of (E)-3,5,4′-trimethoxystilbene in biological matrices, so pharmacokinetic data and suitable methods for determination of the
compound in plasma are currently lacking. A rapid and sensitive liquid chromatographic–mass spectrometric method for determination
of (E)-3,5,4′-trimethoxystilbene in rat plasma, using carbamazepine as internal standard, has been developed and validated. Plasma
samples were treated with acetonitrile to precipitate proteins. Samples were then analyzed by HPLC on a 250mm × 4.6 mm i.d.,
5-μm particle, C18 column with methanol–water, 80:20 (v/v), containing 10 mm ammonium acetate and 0.2% formic acid (pH 3.0), as mobile phase, delivered at 0.85 mL min−1. A single-quadrupole mass spectrometer with an electrospray interface operated in selected-ion monitoring mode was used to
detect [M + H]+ ions at m/z 271.3 for (E)-3,5,4′-trimethoxystilbene and m/z 237.5 for the internal standard. (E)-3,5,4′-trimethoxystilbene and the internal standard eluted as sharp, symmetrical peaks with retention times of 8.9 and 4 min,
respectively. Calibration plots for (E)-3,5,4′-trimethoxystilbene in rat plasma at concentrations ranging from 0.01 to 5.0 μg mL−1 were highly linear. Intra-day and inter-day precision, as RSD, was <12.9%, and accuracy was in the range 94.8–104.7%. The
limit of detection in plasma was 0.005 μg mL−1. The method was successfully used to determine the concentration of (E)-3,5,4′-trimethoxystilbene after oral administration of 86 mg kg−1 of the drug to Sprague–Dawley rats and can be used to investigate the pharmacokinetics of the compound. 相似文献
16.
Two alternating narrow band gap (NBG) copolymers derived from 5,11-di(N-9-heptadecanyl)-indolo[3,2-b]carbazole (ICZ) and 4,7-di(thien-2-yl)-2′,1′,3′-benzoselenadiazole (DSeBT) or 4,7-di(thieno[3,2-b]thien-2-yl)-2′,1′,3′-benzoselenadiazole (DTSeBT), were synthesized and named PICZ-DSeBT and PICZ-DTSeBT, respectively. The
PICZ-DSeBT shows good solubility in common organic solvent, and the PICZ-DTSeBT is soluble in hot o-dichlorobenzene (ODCB) and not good soluble in chloroform, toluene etc. The chemical structure, molecular weight and fundamental
physical properties of the copolymers were characterized by 1H NMR, gel permeation chromatography (GPC), cyclic voltammetry (CV), thermal gravimetric analysis (TGA) and differential scanning
calorimetry (DSC) etc. Potential application of the copolymers to be employed as electron donor material and PC61BM ([6,6]-phenyl-C61 butyric acid methyl ester) for photovoltaic solar cells (PSCs), were investigated. PSCs based on the blends of PICZ-DSeBT/PC61BM (w: w; 1: 2) or PICZ-DTSeBT/PC61BM (w: w; 1: 2) with devices configuration as ITO/PEDOT: PSS/blend/Al, show the power conversion efficiencies (PCEs) of 1.06%
and 1.52%, with the open circuit voltage (V
oc) of 0.75 V and 0.70 V, short circuit current densities (J
sc) of 3.45 mA/cm2 and 5.30 mA/cm2 under an AM1.5 simulator (100 mW/cm2) and the photocurrent response on-set wavelength extending up to 760 nm and 800 nm, respectively. It indicates that the NBG
copolymers are viable electron donor materials for PSCs. 相似文献
17.
Rhony Aufdenblatten Simon Diezi Antonio Togni 《Monatshefte für Chemie / Chemical Monthly》2000,37(5):1345-1350
Starting from the dinuclear chloro-bridged Ir(I) complexes [IrCl(PP)]2 (PP = (R)-(6,6′-dimethylbiphenyl-2,2′-diyl)-1,1′-bis-(diphenylphosphine), (R)-(6,6′-dimethoxy-biphenyl-2,2′-diyl)-1,1′-bis-(diphenylphosphine), and (R)-1-((S)-2-(diphenylphosphino-ferrocenyl))-ethyldicyclohexylphosphine), a new class of cyclopentadienyl Ir(I) complexes containing
a chiral bisphosphine ([IrCp(PP)]) was prepared and characterized. These new complexes are suited precatalysts for the direct hydroarylation of norbornene
with benzamide. 2-(exo-Norbornyl)-benzamide is formed with an enantiomeric excess of up to 94% by the use of 1 mol% iridium, albeit in low yield. 相似文献
18.
Shuxin Li Falong Jiang Yanjin Zhao Jinhua Guo Zhiqing Wang 《Frontiers of Chemistry in China》2007,2(2):218-221
A new method for the preparation of 9-β-D-2′-deoxyribofuranosyl-6-methylpurine from inosine (1) is described. Inosine was converted to 6-chloropurinenucleoside (4) via acetylation, chlorination, and deacetylation. Compound 4 was transformed to the key intermediate 6-methylpurinenucleoside (7) via protection of the 2′,3′,5′-hydroxy groups of 4 with 3,4-dihydropyran to give compound 5, then methylation at the 6-position of 5 with dimethyl copper lithium gave compound 6; depyranylation of 6 led to the subsequent selective protection of the 3′,5′-hydroxy groups of 7 with O[Si(I-Pr)2Cl]2 followed by reaction with phenyl chlorothionoformate to give compound 9. Compound 9 was then converted to the target compound 11
via 2′-deoxidation and 3′, 5′-desilylation. The structures of these products were identified by Mass Spectrum (MS), 1H-NMR (Nuclear Magnetic Resonance) spectra and elemental analysis.
Translated from Chinese Journal of Organic Chemistry, 2006, 26(10): 1394–1397 (in Chinese) 相似文献
19.
Shinya Hayami Yoshihiro Kojima Daisuke Urakami Kazuchika Ohta Katsuya Inoue 《Monatshefte für Chemie / Chemical Monthly》2009,34(4):829-838
Abstract
Metal complexes with long alkyl chains [Co(C16-terpy)3](BF4)2 (1), [Fe(C16-terpy)2](BF4)2 (2), [Co(C16-terpy)2](BPh4)2 (3), [Co(C14-terpy)2](BF4)2 (4), and [Fe(C12C10C5-terpy)2](BF4)2 (5) were synthesized and their physical properties characterized, where C16-terpy, C14-terpy, and C12C10C5-terpy are 4′-hexadecyloxy-2,2′:6′,2′′-terpyridine, 4′-tetradecyloxy-2,2′:6′,2′′-terpyridine, and 4′-5′′′-decyl-1′′′-heptadecyloxy-2,2′:6′,2″-terpyridine, respectively. Complexes 1, 2, and 5 exhibited liquid–crystal properties in the temperature ranges of 371–528 K and 466–556 K, and 88–523 K, respectively. Variable-temperature magnetic susceptibility measurements revealed that the Co(II) complexes 1 and 4 exhibited unique spin transitions (T 1/2↓ = 217 K and T 1/2↑ = 260 K for 1 and T 1/2↓ = 250 K and T 1/2↑ = 307 K for 4), so-called ‘reverse spin transition,’ induced by structural phase transitions. Complex 3 exhibited gradual spin-crossover behavior (T 1/2 = 160 K.), and complex 5 exhibited spin transitions (T 1/2↑ = 288 K and T 1/2↓ = 284 K) at the liquid crystal transition temperature. Compounds with multifunction, i.e., magnetic and liquid–crystal properties, are important in the development of molecular materials. 相似文献20.
The anorexic drug (+)-(2S, 3S, 4S)-phendimetrazine-2R, 3R)-bitartarate crystallized in the orthorhombic space groupP212121 and at 293 Ka=7.7710(4),b=13.1379(7),c=15.9913(9) Å,V=1632.6(2) Å3,Z=4,R(F)=0.062, andR
w
(F)=0.026. A chair conformation 2,3-trans-1,4-oxazine ring with equatorially oriented 2-phenyl,3-methyl, andN-methyl substituents was found as predicted by an earlier reported solid-state CP-MAS13C-NMR investigation of crystalline (±)-phendimetrazine bitartarate. The O-CH2-CH2-N torsion angle of –58.4(6)° in the solid-state agrees nicely with the 56.0(7)° dihedral angle value estimated by1H NMR spectroscopy for the major (equatorialN-methyl) phendimetrazine mesylate species in CD2Cl2 solution. A common solid-state conformational arrangement was found for (+)-phendimetrazine and a series of six other anorexic drugs structurally analogous to (+)-(2S, 3S)-pseudoephedrine. In this arrangement, NCH(Me)CPh has (S)-configuration, there is a (–)-gaucheMe-CH-C-Ph torsion angle, an antiperiplanarN-CH-C-Ph torsion angle, and the phenyl ring approximately eclipses the C-H bond of the attached carbon (e.g., H-C-Cipso-Cortho ca. 4° for 2,3-transphendimetrazine). Nonbonded interactions involving the 3-methyl and the 2-phenyl groups open up the H-C-Cipso-Cortho angle in a series of solid-state structures containing the epimeric (–)-(2R, 3S)-ephedrine moiety (e.g., ca. 45° for molecular mechanics calculated 2,3-cis-phendimetrazine model). 相似文献