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1.
《Tetrahedron》1986,42(7):2121-2128
A number of mesoionic compounds (2) derivatives of the 1,2,4-triazolo[4,3-]-1,2,4-triazole ring system have been prepared from 4-amino-1 -methyl -3,5-bis(methylthio)- 1,2,4-triazolium cation and aryl isothiocyanates. Compounds ((2) react with methyl iodide to give the methiodides ((3) which undergo ring opening to the monocyclic compounds ((4) through sulfur extrusion under thermal conditions. Methiodides ((3) by sequential treatment with malononitriIe and hydrochloric acid lead to the pyrazolo[5,1-]-1,2,4-triazole (6). 相似文献
2.
2-Hydroxybenzoic acid heated with 2,4 - bis(4 - methoxyphenyl) - 1,3,2,4 - dithiadiphosphetane - 2,4 -disulfide, 1, gave 2 - (p - methoxyphenyl) - 4 - 1,3,2 - benzoxathiaphosphorin - 4 - one 2 - sulfide, 3, and its thio-analogue, 4, while its ethyl or phenyl esters gave 4 as the sole product. 2 - Mercaptobenzoic acid and its ethyl ester when heated with 1 produced 3 - 1,2 - benzodithiole - 3 - one, 8, 3 -1,2 - benzodithiole - 3 - thione, 9, and 2- (p - methoxyphenyl) - 4 - 1,3,2 - benzodithia - phosphorin - 4 - one 2 - sulfide, 10. The reaction of 2 -aminobenzoic acid with 1 gave 1,2 - dihydro - 2 - (p - methoxyphenyl) - 4 - 3,1,2 - benzoxaphosphorin - 4 - one 2 - sulfide, 12. Reactions of 1 with methyl 2 - aminobenzoate and 2 - aminobenzamides are described. Mechanistic considerations for the formation of the heterocyclic phosphorus compounds are presented. 相似文献
3.
Enamino-thiones 1 prepared from the corresponding enaminones by thiation with Lawesson's Reagent, were allowed to react with 2-chloroacrylonitrile and dimethyl acetylenedicarboxylate giving dihydro-2-thiopyrans, 2, and 4-thipyrans, 3, respectively. The reaction of 1a with ethyl propiolate at room temperature afforded 4-thipyrans, 4a, which on standing rearranged to 2-thiopyran, 5a(1, 3 amide shift). The reaction of 1b with ethyl propiolate produced 4b and 5b. Some of the 13C NMR data are reported. 相似文献
4.
Methods were developed to prepare 1 -methyl-, 3-methyl- and 4-0-methyl-ψ-isocytidine by selective methylation.35O-Tetraisopropyldisiloxanyl-ψ isocytidine (8) was trimethylsilylated and then treated with MeI and, after deprotection, 1 -methyl-ψ isocytidine (6) was obtained. The 2deoxy analog (7) was also prepared in a similar manner from the 2deoxy analog (10) of 8. Treatment of 8 with CH2N2 afforded the 3-methyl-ψ-isocytidine derivative (19) as the major product. Methylation with diazomethane also occurred mainly on N3 of the 2deoxy analog 10 to form 20. Removal of the 3 5O-protecting group from 19 and 20 afforded 3-methyl-ψ-isocytidine (14) and its 2-deoxy analog (15), respectively. 2-N-Acetyl- 35O-tetraisopropyldisiloxanyl-ψ-isocytidine (24), on the other hand, gave the 4-O-methyl derivative (25) as the major product upon CH2N2 treatment. Subsequent deprotection of 25 afforded 4-O-methyl-ψ-isocytidine (29). aiv51b1p33b 相似文献
5.
Wiley J. Youngs Barbara L. Simms James A. Ibers 《Journal of organometallic chemistry》1984,272(2):295-307
When (t-Bu)2PCH2CHCH2CH2 is combined with [IrCl(C8H14)2]2 in toluene, the σ-bound cyclopropane complexes (P(t-Bu)2CH2H2) (1a, 1b) are formed. Complexes 1a,1b react readily with H2 to form IrClH2P(t-Bu)2CH2H2)2 (2). In polar solvents 1a,1b isomerize to the σ-vinyl chelated complex H)(P(t-Bu)2CH2H2) (3). The structure of this 5-coordinate, 16-electron IrIII complex was deduced from spectroscopic data, reaction chemistry, and from the crystal structure of its CO adduct (4). Compound 4 crystallizes in the monoclinic space group C2h5-P21/n (a 15.610(14), b 15.763(16), c 11.973(13) Å, and β 104.74(5)°) with 4 molecules per unit cell. The final agreement indices for 2326 reflections having Fo2 > 3σ(Fo2) are R(F) = 0.089 and Rw(F) = 0.095 (271 variables) while R(F2) is 0.148 for the 3423 unique data. Bond lengths in the 5-atom chelate ring are IrP 2.341(4), PC 1.857(26), CC 1.520(30), CC 1.341(25), and CIr 1.994(21) Å. The IrCl distance is 2.479(5) Å. 相似文献
6.
A stereoselectivity in an intramolecular cycloaddition of the olefinic -quinodimethanes 13 and 23 generated from the thermolysis of optically active 4β-[2-(4-methoxybenzocyclobutenyl)ethyl] -5α-methoxymethyl-3-phenyl-thio-methylenefuran-2-ones 12 and 22, respectively, is studied and a stereoselective synthesis of (+)--4,5-( 4-methoxybenzo) -1β,7aβ-(2α-methoxymethyl-5-oxofuro)hydrindane 1 is also described. 相似文献
7.
The indolization of deoxybenzoin ,, (Me, MeO, Cl), -NO2 and -EtO-phenylhydrazones (1) by the above reaction has been examined. All the reactions are carried out at room temperature and high yields of the corresponding indoles (2) are obtained even when -NO2 substituent is present. In this case longer reaction time is necessary. Alkoxyphenylhydrazones give the corresponding indoles (2) in high yields without showing collateral reactions which indeed are present in several Fischer routes on these derivatives. -Substituted phenylhydrazones (1) give a mixture of 4- and 6-substituted indoles in which the 6-isomer is always prevalent, a feature not inherent in the Fischer reactions. The regioselectivity is enhanced by the substituent steric hindrance increasing. The reaction can be also carried out at 0°C with a further improvement of its regioselectivity. 相似文献
8.
Georg Grötsch Wolfgang Malisch Herbert Blau 《Journal of organometallic chemistry》1983,252(2):C19-C22
The reaction of the phosphonium metallates Me4P[C5R5(CO)(Me3P))R′] (M = W, R = H, R′ = Et (1a); M = Mo, R = Me, R′ = Me (1b)) with the silylating reagent Me3SiOSO2CF3 yields the neutral complexes C5R5(CO)(Me3P))R (2a, 2b) bearing a chelating O(2), C(4)-trimethylsiloxybutenone ligand. The structure of the new compounds is established by the IR, 1H and 31P NMR spectra. 相似文献
9.
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11.
The copolymerizations of N-(3-dimethylaminophenyl) maleimide (I) and 4-(2-chlorophenyl)azo-3-maleimido-N,N-dimethylaniline (II) with styrene were investigated; the copolymerization parameters of the pairs () and () and hr I at 50° were determined; chain transfer to the maleimide ring of I was proved. The homopolymerization of styrene in the presence of 4-(2-chlorophenyl)azo-succinimide-N,N-dimethylaniline (III) was used to determine the ratio of the rate constant for addition of the polystyrene radical to the azo group in III to kp for styrene. 相似文献
12.
Lithiation of both ()- and ()-3-trimethylsilyl-2-propenyl ,-diisopropyl carbamate 2 affords the (2) -lithium compound 3. Aluminium- or titanium-mediated addition to aldehydes, 4 gives (1)-(3*4*)-enol carbamates 7. A stereospecific Peterson elimination (borontriflouride- or base-mediated) introduces the second double bond either with (3)- or with (3)-configuration. So just by reagent selection for each of the two steps, (1,3)-, (1,3)-, (1,3)-, or (1,3)- dienes 8 - 11, respectively, are prepared with stereoselectivities up to > 99.7% 相似文献
13.
Photoisomerization of -benzocycloheptenone to benzocycloheptenone and its [4 + 2] cycloaddition with selected dienes is reported for the synthesis of fused benzobicyclo[5.3.0]decanes 10, 12 and benzobicyclo [5.4.0]undecanes 13, 15. 相似文献
14.
Cycloaddition reactions between vinyl ethers 3 and -quinone methides 2, thermally generated from 2-hydroxybenzyl alcohols 1, have been studied. The structure and conformational preferences of the 4-substituted 2-ethoxy-(2,3)-dihydro-2-benzopyrans 4–9 obtained, which show new interesting features, are discussed together with competitive kinetic data. The cycloaddition process is concerted and involves -quinone methides in the -configuration. The OEt- transition state seems to be preferred with ethyl vinyl ether and -1-propenyl ethyl ether, whereas with -1-propenyl ethyl ether the stereoselectivity of the cycloaddition process depends on substituents on the methylene group of the starting alcohol 1. These results are discussed in terms of and preference of the propenyl ether methyl group. 相似文献
15.
Martin A. Bennett Tai-Nang Huang Jozef L. Latten 《Journal of organometallic chemistry》1984,272(2):189-205
The η-hexamethylbenzenehydridoruthenium(II) complexes RuHCl(η-C6Me6)L (L = PPh3 (11), AsPh3 (12), P(C6H4-p-F)3 (14), P(C6H4-p-Me)3 (15), P(C6H4-p-OMe)3 (16), P-t-BuPh2 (17), P-i-PrPh2 (18), P-i-Pr3 (19), PCy3 (20) and P-t-BuMe2 (21)) have been made by heating [RuCl2(η-C6Me6)]2, the ligand and sodium carbonate in propan-2-ol. The triarylphosphine complexes 11, 14 and 15 react with methyllithium to give aryl ortho-metallated hydridoruthenium(II) complexes such as Ph2)(η-C6Me6) (22) and 19 similarly gives the isopropyl cyclometallated complex -i-Pr2(η-C6Me6) (29) as a mixture of diastereomers. Reaction of 17 with methyllithium gives initially the t-butyl cyclometallated complex Ph2)(η-C6Me6) (25) which isomerizes by a first order process (k.2 h?1 in C6D6 or THF-d8 at 50°C) to the aryl ortho-metallated complex -t-BuPh)(η-C6Me6) (26). The similarly generated isopropyl cyclometallated complex Ph2)(η-C6Me6) (27) has not been isolated in a pure state owing to rapid isomerization to -i-PrPh)(η-C6Me6) (28); both 27 and 28 exist as a pair of diastereomers. The formation of the cyclometallated complexes and the isomerizations are thought to involve intermediate 16-electron ruthenium(O) complexes Ru(η-C6Me6)L. 相似文献
16.
The kinetics of the homopolymerizations of styrene, N-(3-dimethylaminophenyl) maleimide (I) and N-(3-dimethylamino-6-methylphenyl) maleimide (II) in benzene and dimethylformamide, and the molecular weights of the polymers were studied. N-(3-Dimethylaminophenyl) succinimide, regarded as a model for polymer I, did not affect the polymerization of styrene. The data indicate degradative transfer of polymer radicals to dimethylformamide and pronounced transfer to monomers I and II (CM ≈ 0.06–0.07). The value of for II is 0.09 . 相似文献
17.
The efficient degradation of to the α-methylene ketone is described. Compound was then converted to the allylic alcohol - the precursor of vitamin D3 relatives. 相似文献
18.
o-Lithomethylphenyl isocyanide is reacted at ?78° with isocyanates and isothiocyanates to produce o-isocyanophenyl-acetamides and -acetothioamides . Isocyanides and are cyclized to indole-3-carboxamides and -3-thiocarboxamides via lithiathion, respectively. Isocyanides are also cyclized by Cu2O catalyst to produce 4,5-dihydro-1,3-benzodiazepin-4-ones with . 相似文献
19.
The vinyloxyborane(5), prepared from (+)--phenyl-3()-butanethioate, 9-BBN triflate and diisopropylethylamine, reacted with -(3-benzyloxypropylidene)benzylamine to give the β-benzylamino thiol ester(6) in a moderate yield, which was efficiently converted to the optically pure thienamycin intermediate(10). 相似文献
20.
The enamino-thione, 1c, reacts with acrylonitrile and 2-chloroacrylonitrile at room temperature to give 3,4-dihydro-4-(1-pyrrolidinyl)-2-thiopyrans, 4 and 5, respectively. The reaction between 1-aryl-3-(1-pyrrolidinyl) (piperidino)-apropene-1-thiones, 1a-c (1d-f), and dimethyl acetylenedicarboxylate gives 4-(1-pyrrolidiny)(piperidino)-4-thiopyrans, 6a-c (6d-f). Compounds 1a-c (1d-f) and ethyl propiolate produce 2-(1-pyrrolidinyl) (piperidino)-2-thiopyrans, 8a-c (8d-f), and a new type of rearrangement is observed. The 2-thiopyran, 9, is formed from 1b and ethyl 3-propiolate, which elucidates the mechanism. 1H and 13C NMR data of 6 and 7 are discussed. 相似文献