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1.
The reaction of the dibromide with McMurry's reagent gives 2,3-dicarbethoxy[6]paracyclophane () in about 40% yield. 相似文献
2.
Starting from 4, 5, 12, 13-tetrakis(methoxycarbonyl)[2.2]paracyclophane (), the penta-(), hexa-(–), hepta-(), and octamethyl-() derivatives have been prepared by a repetitive formylation-reduction sequence. 相似文献
3.
Vinyl -xylylene cross-dimerizes with other xylylene-type intermediates to yield cycloadducts of the [8+6] and [6+6] type. This reaction provides a simple entry to the [4.2]paracyclophane system as well as the analogous [4.2]cyclophanes containing furan and pyrrole moieties. 相似文献
4.
The synthesis of [2.2]paracyclophane-iron complexes (R=H or Me) is described. 相似文献
5.
4,16-Dibromo[2.2]paracyclophane (4) is isomerised to 4,12-dibromo[2.2]paracyclophane (1) by the application of microwaves in DMF solution. 相似文献
6.
The title compound 1 prepers the conformations / predicted for [6]paracyclophane; the barrier for the intramolecular process ? was found to be Δ G+ = 13.9 kcal/mol at +4°C. 相似文献
7.
Pyrolysis of the [2.2]paracyclophanyl diazomethane (1) at 270–300°C led to the product of carbon-hydrogen insertion (2) and -1,2-dehydro[3.2]paracyclophane (3). 相似文献
8.
V. A. Nikanorov V. G. Kharitonov E. V. Yatsenko D. P. Krut'ko M. V. Galakhov S. O. Yakushin V. V. Mikul'shina V. I. Rozenberg V. N. Guryshev V. P. Yur'ev O. A. Reutov 《Russian Chemical Bulletin》1992,41(8):1430-1434
From the reaction mixtures in the uncatalyzed polybromination of [2.2]paracyclophane by the action of excess Br2 in CCl4, there have been found along with the known products — 4,15- and 4,16-dibromo[2.2]paracyclophanes — two new aromatic tribromides of this series, which have been isolated in pure form: 4,12,15- and 4,15,16-tribromo[2.2]paracyclophanes. Special experiments demonstrated that the mixtures of these tribromides are formed as a result of competitive monobromination of 4,15-dibromo[2.2]paracyclophane; the 4,15,16-tribromo[2.2]paracyclophane, together with still another newly isolated isomer of this series — 4,8,12-tribromo[2.2]paracyclophane — is formed as a result of competitive monobromination of 4,16-dibromo[2.2]paracyclophane. As an explanation of the features of the orienting effect of substituents in these competing reactions, a rule was proposed: On the conventional orientation (from the electronic point of view) of entry of the bromine atom into the substituted ring (para > ortho > meta), a steric limitation is imposed on its attack in the pseudo-gem-position, owing to the bulky bromine atom that is transannularly positioned above it in the neighboring aromatic ring. The structures of all of the tribromides were established on the basis of elemental analyses, mass spectrometry, and1H NMR spectrometry (including PMR using the homonuclear Overhauser effect). The data obtained in this work indicate that the 4,12,15-tribromo[2.2]paracyclophane and 4,15,16-tribromo[2.2]paracyclophane are predecessors of the two tetrabromides previously obtained by Cram — 4,7,12,15- and 4,5,15,16-tetrabromo[2.2]paracyclophanes; and the 4,8,12-tribromo[2.2]paracyclophane is a possible predecessor of 4,8,12,16-tetrabromo[2.2]paracyclophane, which is unknown up to the present time.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1837–1843, August, 1992. 相似文献
9.
G. I. Borodkin I. R. Elanov R. V. Andreev M. M. Shakirov V. G. Shubin 《Russian Journal of Organic Chemistry》2006,42(3):406-411
The reaction of [2.2]paracyclophane with nitrosonium tetrachloroaluminate was studied by NMR (1H, 13C) spectroscopy using deuterium isotopic perturbation technique. The resulting cationic complexes containing one and two nitrosonium ions are involved in fast (on the NMR time scale) interconversion. Quantum-chemical calculations performed on the DFT level (using triple zeta basis set) indicate the higher stability of 2η single-charged π-complexes relative to σ complexes corresponding to the addition of NO+ ion at the ipso and ortho positions. The formation of the single-charged π-complex is energetically more favorable, compared to the double-charged π-complex. The affinity of NO+ for [2.2]paracyclophane is much greater than for p-xylene, presumably due to stacking interaction between the aromatic rings in the π-complex. 相似文献
10.
L. I. Zakharkin V. A. Ol'shevskaya L. E. Vinogradova 《Russian Chemical Bulletin》1997,46(6):1158-1163
Methods for the synthesis of [2,2]paracyclophane derivatives containingo- andm-carboranyl substituents in position 4, separated from the [2,2]paracyclophane system by one or two C atoms (alcohols and
ketones) were developed. The Clemmensen reduction of a number of ketones of the [2,2]paracyclophane ando-carbonane series occurs abnormally. The reduction of 1-benzoyl-o-carboranes to the corresponding alcohols by zinc in ethanol in a neutral medium was performed for the first time.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1206–1211, June, 1997. 相似文献
11.
Our ongoing study on cycloaddition reactions of dienes with different dienophiles afforded a great variety of derivatives
with interesting molecular structures and electronic behavior. A new type of angularly annelated [2.2]paracyclophane (3) has been synthesize by the Diels–Alder reaction of 4-(2-propenyl[2.2]paracyclophane (1) and 1,4-benzoquinone (2) under high pressure conditions. The structure determination of this compound has been achieved by NMR measurements and semiempirical
calculations. 相似文献
12.
Hinrichs H Boydston AJ Jones PG Hess K Herges R Haley MM Hopf H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(27):7103-7115
A series of [2.2]paracyclophane/dehydrobenzo[14]annulene (PC/DBA) hybrids (hydrocarbons 5, 6, 9, 10 b, and 10 c), [2.2]paracyclophane/dehydro[14]annulene (PC/DA) hybrids (7 and 8) and suitable model systems (11, 12, and 33) has been synthesized. Comparison of the electronic absorption spectra in each series of compounds provides further insight into the global communication between the decks in the [2.2]paracyclophane unit. 相似文献
13.
N. V. Vorontsova V. I. Rozenberg E. V. Vorontsov O. L. Tok Yu. N. Bubnov 《Russian Chemical Bulletin》2000,49(5):912-919
Stereoselectivity of allylboration of 4-formyl[2.2]paracyclophane, 4-acetyl[2.2]paracyclophane, and 4-hydroxy-5-formyl[2.2]paracyclophane
was studied and the relative configurations of the homoallylic alcohols obtained were established. Optically pure (Sp,Sc)-(+)-4-(4-hydroxy-1-methylbut-3-enyl)[2.2]paracyclophane and (Rc,Sc)-(+)-4-hydroxy-5-(4-hydroxybut-3-enyl)[2.2]paracyclophane were synthesized. The possibility of using (Sp,Sc)-(+)-4-(4-hydroxy-4-methylbut-3-enyl)[2.2]paracyclophane as a recoverable chiral auxiliary in asymmetric allylboration of
aldehydes was demonstrated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 914–921, May, 2000. 相似文献
14.
Geng-Shuen Wu I. C. Martinelli C. Dewitt Btanton Richard H. Cox 《Journal of heterocyclic chemistry》1977,14(1):11-17
The synthesis of N-methyl-3-aza[10]paracyclophane is reported which represents the first example of this ring system being formed via an acyloin reaction. This 3-aza[10]paraeyclophane ring system behaves physiochemically inbetween the normal [9]- and [10]paracyclophane ring systems. Reductive desulfurization of N-methyl-3-aza[10]paracyclophane-6-ethylene thioketal in ethanol provides a small amount of the title compound and an unexpected, ring-opened product, N-ethyl-N-methyl-p-heptylphenethylamine. A possible mechanism for the ring-opening process is suggested. 相似文献
15.
Kreis M Friedmann CJ Bräse S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(24):7387-7394
A Hartwig-Buchwald addition of a variety of chiral amines to rac-4-bromo-[2.2]paracyclophane and rac-trifluoromethanesulfonic acid (4-[2.2]paracyclophane) ester was performed with high diastereoselectivities. Kinetic racemic resolution of the starting materials was achieved, providing a rapid access to enantiomerically enriched 4-bromo-[2.2]paracyclophane and the corresponding enantiomerically pure [2.2]paracyclophane amines. Additionally, the first reaction of a secondary amine with a [2.2]paracyclophane halide was achieved. 相似文献
16.
A comparative molecular orbital study of [2.2]paracyclophane and simple arenes as ligands toward a Cr(CO)3 group was performed with the aim of accounting for the observed coordination patterns. While the inter-ring repulsion is
an important factor in [2.2]paracyclophane activation, it is not the only one. The molecular orbitals of two arene rings stacked
parallel to each other were analyzed in some detail. The inward hybridization (toward the other ring) of the (arene)2 HOMO was shown to reduce the strength of consequent bonding with the Cr(CO)3 is fragment. The overall stabilization of [2.2]paracyclophane complex with Cr(CO)3 is enhanced by a reduction of the inter-ring repulsion and strengthening of the Ar−Cr bond, and reduced by weakening of the
intra-ring carbon-carbon bonds. The inter-ring repulsion increases with approach of the arenes to each other, as appears to
happen in the structure of [2.2]paracyclophane complex with Cr(CO)3. This explains the high donor ability of the free ring of the (arene)2Cr(CO)3 complex toward another Cr(CO)3 fragment. It was proposed that the stabilization of the [2.2]paracyclophane complex with Cr(CO)3 results ultimately from the relaxation of the strained framework of [2.2]paracyclophane. The kinetic factor in Cr(CO)3 complexation was also studied by analyzing the charges on competing arene rings in monoaryl-substituted derivatives of [2.2]paracyclophanes.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 151–157, January, 1998. 相似文献
17.
Mikio Hori Kiyomi Tanaka Tadashi Kataoka Hiroshi Shimizu Eiji Imai Kazuhiko Kimura Yoshinobu Hashimoto 《Tetrahedron letters》1985,26(10):1321-1322
5,7-Dimethyl[1,2,4]triazolo[1,5-a]pyrimidinio-3-phenacylide () generated by the reaction of an iminium salt () with 1 eq. of triethylamine, underwent a new thermal ring cleavage of the triazole moiety to give the pyrimidine derivative. However reaction of with 2 eq. of triethylamine afforded the 2-iminooxazoline derivative. The iminooxazoline reacted with nucleophiles such as alcohols or amines to give imidazoles. 相似文献
18.
Planar chiral hydroxy derivatives of [2.2]paracyclophane as auxiliaries for asymmetric allylboration
N. V. Vorontsova R. P. Zhuravsky E. V. Sergeeva E. V. Vorontsov Z. A. Starikova V. I. Rozenberg 《Russian Chemical Bulletin》2007,56(11):2225-2231
Allylboronic esters with various structures were synthesized for the first time based on [2.2]paracyclophane derivatives containing
one or two hydroxy groups. It was demonstrated that these esters can be used as chiral inductors in the asymmetric allylboration
of benzaldehyde. The highest enantiomeric excess of 1-phenylbut-3-en-1-ol (60%) was achieved in the reactions with acyclic
bis-O,O′-(paracyclophanyl) allylboronates based on (S)-4-hydroxy-and (S)-12-bromo-4-hydroxy[2.2]paracyclophanes. (S)-4-Hydroxy[2.2]paracyclophane was studied by X-ray diffraction.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2149–2155, November, 2007. 相似文献
19.
Dolbier WR Xie P Zhang L Xu W Chang Y Abboud KA 《The Journal of organic chemistry》2008,73(6):2469-2472
A synthesis of perfluoro[2.2]paracyclophane has been sought ever since the partially fluorinated octafluoro[2.2]paracyclophane (AF4) was prepared and its chemistry studied. This compound has now been prepared in 39% yield from the precursor, 1,4-bis(chlorodifluoromethyl)-2,3,5,6-tetrafluorobenzene by its reaction with Zn when heated in acetonitrile at 100 degrees C. Two preparations of the precursor, first from 1,4-dicyano-2,3,5,6-tetrachlorobenzene and an improved method beginning from 1,2,4,5-tetrachlorobenzene, are also described as are key comparisons to our related synthesis of AF4. 相似文献
20.
L.A.M. Turkenburg P.M.L. Blok W.H. de Wolf F. Bickelhaupt 《Tetrahedron letters》1981,22(34):3317-3320
Base induced elimination of HCl from the dichloro[5.3.1]propellane gives a mixture of [5]metacyclophane () and tetrahydrocyclopentacyclooctenes (), while the stereoisomeric affords quantitatively. 相似文献