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1.
Reaction of the amines (CF3)2NX (X=Cl,Br) with norbornadiene either in solvent (CH2Cl2) at ?78 °C in the dark or in the vapour phase at 20 °C in daylight gives a mixture of 3-halogeno-5-(-bistrifluoromethylamino)nortricyclene (, -and , -isomers) and -5-(-bistrifluoromethylamino)- -7-halogenonorbornene in quantitative yield formed halonium ion addition to the diene. The reaction of the amine (CF3)2NBr in solvent Me2O or Et2O at ?78 °C in the dark gives the same products in low yield, together with 3-bromo-5-alkoxynortricyclene (, - and , -isomers) and the amine (CF3)2NR (R=Me, Et) in high yield. 相似文献
2.
Optical absorption and emission spectra are reported for single crystals of the cubic elpasolite Cs2NaSmCl6. The variable temperature spectra obtained at high resolution are assigned using energies and relative intensities. Transitions from the ground level, 6H to cystal fi levels of 6H-, 6F-, 4G-, 4F,, 4I, and 6P, are located and characterized. Intensity calculations are reported for magnetic dipole allowed transitions. The dominance of vibronic intensity in 6H→6F - and 6P, transitions is accounted for qualitatively through the ligand polarization model involving quadrupole metal (Sm3+)-ligand (Cl?) interaction mechanisms. The Eu″(6H)→E′(6H) Eu′(6F) no-phonon transition is postulated to be pure electric quadrupole allowed. The ground state magnetic moment is determined to be very small from magnetic circular dichroism (MCD) spectra.This study has led to the assignment of nearly all of the crystal field levels in the visible and IR region for Cs2NaSmCl6. A total of 27 such levels were identified, 17 from no-phonon transitions and the rest from vibronic transitions. The magnetic dipole intensity calculated using intermediate coupling Oh wavefunctions along with a crystal field analysis of the splitting pattern was used in the assignment of the levels. Vibronic bands were observed for all transitions and their vibrational symmetries were tentatively assigned. MCD data were used to determine the magnet moment of the ground state. 相似文献
3.
The diene reacted with CHCl3/aq. NaOH/PTC in CH2 Cl2 unexpectedly to give a mixture of the chlorination products and . Usual chlorination with Cl2 yielded similarly , , and dependent on the amount of Cl2. The formation of as well as the reaction of to give (besides ) shows an unusual Cl-Cl-interaction. 相似文献
4.
Oxidation of benzotropylium () fluoborate with Na2O2 and KO2 gives the benzotropones, and , as the major products with no naphthalene () or other ring contracted products formed. Oxidation with -chloroperoxybenzoic acid produces a small amount of naphthaldehydes ( and ) and even less naphthalene, a long with the benzotropones, while oxidation with H2O2 and -butyl peroxyacetate gives slightly more of the ring contracted naphthaldehydes than benzotropones, in addition to a small quantity of naphthalene. All reactions produce some 1,2-benzotropilidene () 相似文献
5.
R.J. Bertino B.A.W. Coller G.B. Deacon I.K. Johnson 《Journal of fluorine chemistry》1975,5(4):335-357
The lithium polyfluorobenzenesulphinates, Li O2SR (R = C6F5, -HC6F4, -HC6F4, or -HC6F4), and the dilithium tetrafluorobenzenedisulphinates, - and -(LiO2S)2C6F4, have been prepared by reaction of the appropriate polyfluoroaryllithium compounds with sulphur dioxide. All compounds were isolated as hydrates and gave the corresponding -benzylthiouronium salts on treatment with -benzylthiouronium chloride. From reactions of the lithium sulphinates with suitable mercuric salts in water, generally at room temperature, the derivatives RHgX (R = C6F5, X = Cl, Br, CH3CO2, or PhSO2; R = -HC6F4, X = Cl, Br, or CH3CO2; R = -HC6F4, X = Cl or Br; R = -HC6F4, X = Cl), -(XHg)2C6F4 (X = Cl, Br, or CH3CO2), and -(XHg)2C6X4 (X = Cl or Br) have been prepared. Similarly, the bispolyfluorophenylmercurials R2Hg (R = C6F5, -HC6F4, or -HC6F4) have been prepared from the corresponding lithium sulphinates and either mercuric salts or polyfluorophenylmercuric halides in aqueous -butanol. A possible mechanism for the sulphur dioxide elimination reactions is discussed. 相似文献
6.
The chlorinative ene-type reaction of isoprenoids ( → ) has been performed by electrolysis in CH2Cl2-H2O-NaCl system. The reaction provides useful allylic chlorides for terpene synthesis in high yields and is affected strikingly by the nature of halide ions and solvents. dl-Theaspirane was prepared from α-dihydroionol the electrolysis. 相似文献
7.
A practical synthesis of [Ph3CH2F]BF4? is reported two routes, fluorination of [Ph3CH2OH]BF4? with DAST or hydrolysis of the phosphoranium salt, [Ph3FPh3]Br?. 相似文献
8.
LDA-induced cyclization of yields , the -isomer of which undergoes dehydration using Ph2S[OC(CF3)2Ph]2 to give the pyrethroid amide . 相似文献
9.
The production of I(2P) in the photolysis of CH2I2 has been studied optoacoustically at excitation wavelengths between 365.5 and 247.5 nm. Bands found at 32200 and 47000 cm?1 correlate with I(2P) whilst those at 34700 and 40100 cm?1, which correlate with I(2P), give final 2P/2P ratios of 1.75 and 1.1, respectively, after curve crossing. 相似文献
10.
Flash vacuum pyrolysis of -methylbenzyl chloride-,-2 gives benzocyclobutene-,-2. This finding indicates that the reaction involves net δ-elimination of hydrochloric acid. 相似文献
11.
A sequence of formylation followed by a carbene insertion reaction has led to the stepwise introduction of additional ethano bridges into 4,5,7,8- tetramethyl [22](1,4)cyclophane (), providing syntheses of 5,7,8-trimethyl- [23](l,2,4)cyclophane (), a mixture of 5,8-dimethyl[24(1,2,4,5)cyclophane () and 5,7-dimethyl[24(1,2,3,5)cyclophane (, and-4-methyl[25](1,2,3,4,5)-cyclophane (). This route to completes a formal eight-step synthesis of [26](1,2,3,4,5,6)cyclophane (, superphane) with an overall yield of 17%. A Birch reduction of readily gave 12,15-dihydro-5,7,8-trimethyl[23](1,2,4)-cyclophane () in 85% yield. 相似文献
12.
Thermodynamic data have been obtained by calorimetric titration in benzene solution at 30° for reaction of organotin compounds with Lewis bases; data are reported for forty acid/base systems.Ph3SnCl forms adducts of low stability with pyridine (py) or 4-methyl-pyridine (4-mepy). Ph2SnCl2, Me2SnCl2, Bu2SnCl2 and Bu2Sn(NCS)2 form simultaneously and adducts with py or 4-mepy and adducts with 2,2′-bipyridine or 1,10-phenanthroline (phen); the enthalpies of formation of the phen adducts are similar to those of adducts with 4-mepy. With BuSnCl3 and PhSnCl3 it was not possible to obtain data for each step in addition of pyridine or 4-mepy. Adduct stabilities increase with increasing chloride substitution and in the order Bu < Me < Ph; adducts of Bu2Sn(NCS)2 are more stable than those of Bu2SnCl2.Tributylphosphine does not react with Ph3SnCl but gives adducts with the other tin compounds; only PhSnCl3 adds a second molecule of this base. The adducts are more stable than those with heterocyclic bases. Tributylamine brings about disproportionation of the compounds R2SnX2 to R4Sn and SnX4NBu3. 相似文献
13.
Treatment of methyl 3,5-dideoxy-β---pentofuranoside with the Ph3P-CCl4 reagent gave none of the expected 2-chloro derivative but a mixture of l→2 linked oligosaccharides, , with some higher homologues, terminated by αa 2-chloro-2,3,5-trideoxy-α---pentofuranosyl unit at the non reducing end. 相似文献
14.
Haruhisa Shirahama Kiyoharu Hayano Yoshiro Kanemoto Shunjiro Misumi Toshikazu Ohtsuka Nobuhiro Hashiba Akio Furusaki Shizuaki Murata Ryoji Noyori Takeshi Matsumoto 《Tetrahedron letters》1980,21(50):4835-4838
Two cyclohumulanoids, dl-bicyclohumulenone () and dl-africanol ( were synthesized through newly developed conformationally selective transannular cyclization of humulene 9,10-epoxide (). The epoxide was converted to a bicyclohumulenediol diacetate in 70% yield by treatment with BF3·OEt2-Ac2O, while treatment of with trimethylsilyl trifluoromethansulfonate gave an africen-10-ol (a and b) in 80% yield. The two intermediates and furnished the natural products and in 30 and 8 % yield from respectively. 相似文献
15.
Federico G. De las Heras Ana San Félix Ana Calvo-Mateo Piedad Fernández-Resa 《Tetrahedron》1985,41(18):3867-3873
Reaction of methyl 2-acetamido-4,6--benzylidene-2-deoxy-α---hexopyranosid-3-ulose with Me3SiCN afforded methyl 2-acetamido-4,6--benzylidene-3--cyano-2-deoxy-3--trimethylsilyl-α--- Reaction of ethyl 4,6-di--acetyl-2,3-anhydro-α--mannopyranoside with Me3SiCN gave the corresponding ethyl 4,6-di--acetyl-2--cyano-2-deoxy-α--glucopyranoside. Reaction of methyl 4,6--benzylidene-2,3-anhydro-α--allopyranoside or methyl 4,6--benzylidene-2,3-di--tosyl-α--glucopyranoside with Me3SiCN at - 75° or - 50° gave the corresponding methyl 6--[(R)-cyano phenyl methyl]-α--glyco-pyranosides with high or total regio and stereoselectivity. 相似文献
16.
Wojciech Dmowski 《Journal of fluorine chemistry》1982,21(2):201-219
1-Phenylpentafluoropropene and its para-substituted analogs are susceptible to nucleophilic attack at both vinylic carbon atoms C-1 and C-2. They react with ethanolio sodium ethoxide to give predominantly substitution products, 1-ethoxy-1-phenyltetrafluoropropenes and 2-ethoxy-1-phenyltetrafluoropropenes , with only little formation of adducts, . 2-ethoxy-1H-1-phenylpentafluoropropanes . Alkenes , where the para-substituent X H,Cl,and CF3 give additionally 1,2-diethoxy-1-phenyltrifluoropropenes and, where X = CF3 also 2,2-diethoxy-1H-1-phenyltetrafluoropropane . Overall regioselectivity of nucleophilic attack of the ethoxide ion on alkenes exhibits the Hammett type correlation with Óp values of substituents X: CH3O and CH3 groups favour the attack on the vinylic carbon C-1, while CF3 and Cl substituents direct the attack on the C-2 carbon of alkenes . The E and Z isomers of 1-ethoxy and 1,2-diethoxy substituted alkenes and were formed in comparable amounts, while the E isomers of 2-ethoxy substituted alkenes were always formed with a 93 – 97 % selectivity. 相似文献
17.
Synthesis and properties of C5H5(CO)2Mn-N2H4-Cr(CC)5, C5H5(CO)2Mn-N2H2-Cr(CO)5 and C5H5(CO)2Mn-N2-Cr(CO)5 are reported. , and constitute the first series of heteronuclear complexes in which N2, N2H2 and N2H4 are bound to identical metal centers. and are obtained by reacting C5H5Mn(CO)2N2H4 respectively with Cr(CO)5THF, by oxidation of . disproportionates by addition of base yielding and H2. The IR Spectrum of allows the assignment of five normal vibrations of the diazene ligand; in the IR spectrum of the deuterated analogue all six normal vibrations can be assigned. The 1H-NMR spectrum of yields the coupling constant of protons on NN double bonds for the first time; the value of 3JHH 23,5 Hz points to a trans structure of . 相似文献
18.
Acid-catalysed ring opening of the spirodienones () and () using p-toluene-sulphonic acid affords the styrène derivatives () and (), while treatment with acetic anhydride/H2SO4 affords the furan derivatives () and (). 相似文献
19.
Adenosine cyclic 3′,5′-phosphoramidate was synthesized by reacting adenosine cyclic 3′,5′-phosphate with POCl3, in trimethyl phosphate for 1 h at O°C, followed by in situ treatment of the reaction mixture with a suspension of (NH4)2CO3 in anhydrous DMF or pyridine or DMF/pyridine mixture for 30 min at 25° C. Diastereoisomers (P)- and (P)- the relative quantities of which depended on the solvent of (NH4)2CO3 treatment, were separated by reversed phase partition chromatography. Hydrolysis of (RP)- and (SP)- proceeded with predominant (90% in 0.1 N HCl, 100% in 0.1 N NaOH) -P-O-C bond breaking. 相似文献
20.
The energies of EPR transitions of 160Gd3+ in La(C2H5SO43 · 9D2O at 77.2 K are observed to be nonlinear functions of field at low fields. The + , + and ?, ? transition energies converge asymmetrically below 10 G and differ by only ≈ MHz at the lowest fields employed. 相似文献