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1.
Barberà G Vaca A Teixidor F Sillanpää R Kivekäs R Viñas C 《Inorganic chemistry》2008,47(16):7309-7316
The use of nucleophilic and electrophilic processes allow the designed synthesis of several B-iodinated derivatives of o-carborane. Because of the straightforward Pd-catalyzed conversion of B-I to B-C bond with Grignard reagents, such as methylMgBr and biPhenylMgBr, both, symmetrical 3,6-R 2-1,2- closo-C 2B 10H 10 and asymmetrical 3-I-6-Me-1,2- closo-C 2B 10H 10 could be obtained. Not only conventional reactions in solution have been studied but also a highly efficient, clean and fast solvent-free procedure has provided successful results to regioselectively produce B-iodinated o-carborane derivatives by a careful control of the reaction conditions. The high number of nonequivalent leaving groups in boron iodinated o-carborane derivatives opens the possibility through B-C coupling to materials with novel possibilities and to self-assembling due to the enhanced polarizability of the C-H bond. 相似文献
2.
It was shown that 1-R-2-benzyl-o-carboranes (R=Me, i-Pr, Ph, PhCH2) and other derivatives of o-carborane containing an ArCH2 group in positions 1 and 2 are readily metallized by n-butyllithium, forming the corresponding benzyllithium derivatives, which react with electrophilic reagents like the usual organolithium compounds, permitting the synthesis of various C-substituted 1-o-carboranes.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 431–435, February, 1992. 相似文献
3.
Hamideh Jalali Seyed Javad Hosseini Safa Ali-Asgari Jafar Izadi Nia 《Journal of heterocyclic chemistry》2020,57(1):419-427
The highly trans-stereoselective reaction of ammonium salt ( AS 2 ) toward (E)-N-benzylidene-4-methylbenzenesulfonamide ( IM 4 ) in the presence of Na2CO3 leading to an aziridine derivative, trans -Az 6 , was theoretically studied using Molecular Electron Density Theory (MEDT) at the B3LYP/6-31G(d) computational level to probe energy transformation, selectivities, and molecular mechanism. The reaction starts by a nucleophilic substitution reaction between 1,4-diazabicyclo [2.2.2]octane ( DABCO ) and phenacyl bromide ( PB ) to form AS 2 which undergoes a proton abstraction by Na2CO3 to produce Ammonium Ylide ( AY 3) . Subsequently, nucleophilic addition of AY 3 to the double bond in IM 4 leads to form a betaine-like intermediate, namely, IN-Ta which named IN-Ta . Finally, trans -Az 6 is produced as a result of the nucleophilic attack of the negatively charged nitrogen atom on the carbon atom bearing DABCO in IN-Ta . Analysis of the relative Gibbs free energies shows that the ring closure step is the rate-determining step (RDS). By an investigation of the conceptual density functional theory, CDFT reactivity indices AY 3 and IM 4 are classified as a strong nucleophilic molecular system and as a strong electrophilic molecular system, respectively, which implies that the addition step of AY 3 to IM 4 has a high polar character. An analysis of the calculated electrophilic and nucleophilic Parr functions at the reactive sites of reagents clarifies the regioselectivity observed experimentally within the C1–C2 bond creation process. 相似文献
4.
G. D. Kolomnikova T. O. Krylova I. V. Chernoglazova P. V. Petrovskii Yu. G. Gololobov 《Russian Chemical Bulletin》1993,42(7):1188-1190
In the presence of trifluoroacetic acid, ethyl 2-cyanoacrylate readily reacts with nucleophilic reagents, such as 2-chloro-1,3,2-benzodioxaphosphole, (EtO)3P, (EtO)2PCl, Ph2PCl, Ph3P, and thiourea. In these reactions the acid proton enters position 2 of the cyanoacrylate, whereas the nucleophilic component enters position 3, in accordance with the electron density distribution in the acrylate. In the absence of trifluoroacetic acid the above reagents, except 2-chloro-1,3,2-benzodioxaphosphole, cause ethyl 2-cyanoacrylate polymerization. The interaction of ethyl 2-cyanoacrylate with 2-chloro-1,3,2-benzodioxaphosphole and trifluoroacetic acid is the first example of a 2-cyanoacrylate taking part in the acid-initiated electrophilic conjugate addition of a weak nucleophile.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1245–1247, July, 1993. 相似文献
5.
V. E. Bel'skii 《Russian Chemical Bulletin》1998,47(2):265-268
Regression analysis of the solvent effects on the rate constants of nucleophilic substitution at the phosphoryl group was
performed with the use of the empirical parameters of solvent polarity which characterize the ability of the solvents to electrophilic
and nucleophilic solvation. The nucleophilic solvation of reagents by solvents, as a rule, favors the phosphorylation reactions.
In the phosphorylation reactions of anionic nucleophiles, the electrophilic solvation of anions influences negatively the
reactions rates. The phosphorylation of amines by chlorides of phosphorus acids is facilitated by the electrophilic solvation
of a separated anion.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 271–274, February, 1998. 相似文献
6.
Catalyst‐Directed Diastereo‐ and Site‐Selectivity in Successive Nucleophilic and Electrophilic Allylations of Chiral 1,3‐Diols: Protecting‐Group‐Free Synthesis of Substituted Pyrans
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Dr. Inji Shin Gang Wang Prof. Michael J. Krische 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13382-13389
The iridium‐catalyzed, protecting group‐free synthesis of 4‐hydroxy‐2,6‐cis‐ or trans‐pyrans through successive nucleophilic and electrophilic allylations of chiral 1,3‐diols occurs with complete levels of catalyst‐directed diastereoselectivity in the absence of protecting groups, premetallated reagents, or discrete alcohol‐to‐aldehyde redox reactions. 相似文献
7.
Dr. Maxim V. Ponomarenko Prof. Dr. Yuriy A. Serguchev Dr. Markus E. Hirschberg Prof. Dr. Gerd‐Volker Röschenthaler Prof. Dr. Andrey A. Fokin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(33):10383-10391
Three reaction paths, namely, molecule‐induced homolytic, free radical, and electrophilic, were modeled computationally at the MP2 level of ab initio theory and studied experimentally for the reaction of F2 with the terminal dienes of bicyclo[3.3.1]nonane series. The addition of fluorine is accompanied by transannular cyclization to the adamantane derivatives in which strong evidence for the electrophilic mechanism both in nucleophilic (acetonitrile) and non‐nucleophilic (CFCl3, CHCl3) solvents were found. The presence of KF in CFCl3 and CHCl3 facilitates the addition and substantially reduces the formation of tar products. 相似文献
8.
Hubert Mimoun 《Angewandte Chemie (International ed. in English)》1982,21(10):734-750
In this progress report an attempt is made to rationalize, from a mechanistic point of view, the different ways in which oxygen is transferred from inorganic and organic peroxides to nucleophilic substrates, particularly olefins. Oxygen transfer from transition-metal peroxides, which is relevant to catalytic oxidations using O2, H2O2 or ROOH, occurs via a cyclic or “pseudocyclic” peroxymetalation in which a dioxametallacycle is formed. Owing to the wide discrepancy between peroxymetalation and the conventional oxidation mechanism, i.e. nucleophilic attack of the substrate at the electrophilic “active oxygen”, we propose an alternative mechanism involving dioxiranes as the reactive species. The generation of dioxiranes appears to be a common denominator in the reactions of most organic peroxides e.g. peroxy acids, the reaction of electrophilic ketones with H2O2, or ozonizations. Oxygen transfer from dioxirane reagents probably involves the formation of a charge-transfer π-complex between the substrate and the carbon atom of the dioxirane, and the subsequent formation of a cyclic peroxidic intermediate. 相似文献
9.
Reaction of tert-butyl-1,2,3,6-tetrahydro-4-[(trifluoromethyl)sulfonyl]pyridine-1-carboxylate with tributylvinyltin in the presence of Pd(PPh3)4-LiCl afforded tert-butyl-4-vinyl-3,6-dihydro-2H-pyridine-1-carboxylate. The latter reacted with maleic anhydride to form tert-butyl-(3aS,9bR)-1,3-dioxo-4,6,7,9,9a,9b-hexahydro-3aH-furo[3,4-h]isoquinoline-8-carboxylate as the Diels-Alder endo-adduct. Reactions of this adduct with electrophilic and nucleophilic reagents, as well as the reduction and oxidation of its functional groups was performed. 相似文献
10.
A. S. Romakhin Yu. G. Budnikova I. M. Zaripov Yu. M. Kargin E. V. Nikitin A. P. Tomilov Yu. A. Ignat'ev V. V. Smirnov 《Russian Chemical Bulletin》1992,41(6):1031-1035
An electrochemical method, based on the joint action of nucleophilic and electrophilic reagents on P4, is proposed in order to utilize white phosphorus in the formation of the esters of phosphorus acids. The action of alkoxide ions on white phosphorus in an alcohol medium in the presence of iodine generated at the anode leads to the formation of phosphate esters. A scheme in which the intermediate products are dialkyl and trialkyl phosphites and the side product is dialkyl alkylphosphonate is proposed for the process.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420028 Kazan'. V. I. Ul'yanov-Lenin Kazan State University, 420028 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1322–1328, June, 1992. 相似文献
11.
S‐((Phenylsulfonyl)difluoromethyl)thiophenium Salts: Carbon‐Selective Electrophilic Difluoromethylation of β‐Ketoesters, β‐Diketones,and Dicyanoalkylidenes
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Xin Wang Guokai Liu Dr. Xiu‐Hua Xu Naoyuki Shibata Etsuko Tokunaga Prof. Dr. Norio Shibata 《Angewandte Chemie (International ed. in English)》2014,53(7):1827-1831
S‐((Phenylsulfonyl)difluoromethyl)thiophenium salts were designed and prepared by a triflic acid catalyzed intramolecular cyclization of ortho‐ethynyl aryldifluoromethyl sulfanes. The thiophenium salts were found to be efficient as electrophilic difluoromehtylating reagents for introduction of a CF2H group to sp3‐hybridized carbon nucleophiles such as of β‐ketoesters and dicyanoalkylidenes. The (phenylsulfonyl)difluoromethyl group can be readily transformed into CF2H under mild reaction conditions. Enantioselective electrophilic difluoromethylation was also achieved in the presence of bis(cinchona) alkaloids. 相似文献
12.
Xin Wang Guokai Liu Xiu‐Hua Xu Naoyuki Shibata Etsuko Tokunaga Norio Shibata 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(7):1858-1862
S‐((Phenylsulfonyl)difluoromethyl)thiophenium salts were designed and prepared by a triflic acid catalyzed intramolecular cyclization of ortho‐ethynyl aryldifluoromethyl sulfanes. The thiophenium salts were found to be efficient as electrophilic difluoromehtylating reagents for introduction of a CF2H group to sp3‐hybridized carbon nucleophiles such as of β‐ketoesters and dicyanoalkylidenes. The (phenylsulfonyl)difluoromethyl group can be readily transformed into CF2H under mild reaction conditions. Enantioselective electrophilic difluoromethylation was also achieved in the presence of bis(cinchona) alkaloids. 相似文献
13.
Summary The synthesis of the new unsymmetrically substituted 16-membered macrocyclic complex, (3-acetyl-2,10,12-trimethyl-1, 5, 9,
13-tetraazacyclohexadeca-1, 3, 9, 11-tetraenato)-NiII, by template-controlled macrocyclization is reported. This complex has a single nucleophilic site available to react with
electrophilic reagents. The crystal structure of the acyclic precursor, (3-acetyl-10-methyl-5,9-diazatrideca-3, 8-diene-2,12-dionato)NiII shows that in the solid state it exists as a pair of enantiomers, arising from the presence of two possible skew boat conformations
adopted by the six-membered saturated metallochelate ring present in the molecule. 相似文献
14.
The triethylamine-initiated polymerization of glycine-NCA [N-carboxylic acid anhydrides (oxazolidine-2,5-diones)], L -alanine-NCA, and sarcosine-NCA, as well as the pyridine-initiated polymerization of sarcosine-NCA, were carried out in the presence of potential cocatalysts. The 11 electrophilic reagents tested in this work can be divided into two classes: N-acyllactams and similar compounds, which are less reactive than the monomers and have no influence on the polymerization; and isocyanates and N-acyl-NCAs or -NTAs [N-thiocarboxylic acid anhydrides (thiazolldine-2,5-diones)], which are more electrophilic than the monomers and behave as cocatalysts in the case of glycine-NCA and alanine-NCA, since their base-initiated polymerization proceeds via the attack of NCA anions on the electrophilic N-acyl NCA chain and (“activated monomer mechanism”). In the case of sarcosine-NCA, however, the propagation involves a nucleophilic chain end (“carbamate mechanism”) and the strong electrophilic reagents behave as inhibitors. 相似文献
15.
Branko Stanovnik Borut Furlan Marko Kupper Lidija Male Anton timac Miha Tiler Marko
li
ar 《Journal of heterocyclic chemistry》1988,25(2):393-398
The nucleophilic and electrophilic substitutions of 6-substituted 9,9-dimethyl-9H-imidazo[1,2-b]pyrazolo- [4,3-d]pyridazines 2 , nucleophilic substitutions of 6-substituted 9,9-dimethyl-9H-pyrazolo[4,3-d]-s-triazolo- [4,3-b]pyridazines 7 and some other transformations to give compounds 3 and 8 , respectively, were studied. It was shown that both heterocyclic systems are stable under the conditions employed in these transformations. 相似文献
16.
Mahmoud. M. M. Ramiz Ibrahim. S. Abdel Hafiz Mohamed. A. M. Abdel Reheim Hatem M. Gaber 《中国化学会会志》2012,59(1):72-80
A series of new pyrazolone and pyrazole derivatives with expected antifungicidal activity have been prepared through the reactions 3‐phenyl‐1‐H‐pyrazol‐5(4H)‐one ( 3 ) and 4‐(dimethylaminomethylene)‐3‐phenyl‐1H‐pyrazol‐5(4H)‐one ( 5 ) with a variety of electrophilic reagents and nucleophilic reagents. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral studies. 相似文献
17.
S. Yu. Kukushkin P. Yu. Ivanov L. M. Alekseeva V. I. Levina K. I. Kobrakov N. B. Grigor'ev V. G. Granik 《Russian Chemical Bulletin》2005,54(8):1887-1891
The half-wave potentials of polarographic reduction of the carbonyl group in unsubstituted and N-methyl- and N-phenylsulfonyl-substituted 1- and 4-oxotetrahydrocarbazoles and their reactivities in reactions with nucleophilic (NaBH4, malonodinitrile, and cyanoacetamide) and electrophilic (DMF dimethyl acetal) reagents were compared. 4-Oxotetrahydrocarbazoles
are much less reactive than 1-oxotetrahydrocarbazoles.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1832–1836, August, 2005. 相似文献
18.
A series of 5-substituted 3-nitro-1-vinyl-1,2,4-triazoles were synthesized by alkaline treatment of the corresponding 1-(2-haloethyl- or 2-nitroxyethyl)-3-nitro-1,2,4-triazoles and by transvinylation of NH acids of the same series with vinyl acetate. The scope of applicability of the transvinylation procedure was established with respect to the azole pK
a value. The vinylic double bond on the nitrogen was shown to be inactive toward both nucleophilic and electrophilic reagents, whereas the halogen atom in position 5 exhibits enhanced reactivity. The latter factor provides the possibility for versatile structural modification via nucleophilic replacement of the 5-halogen atom by various groups, including triazolate ion. 相似文献
19.
N. K. Gusarova S. F. Malysheva S. N. Arbuzova B. A. Trofimov 《Russian Chemical Bulletin》1998,47(9):1645-1652
Data on the reactions of elemental phosphorus and phosphine with electrophilic reagents are described systematically and analyzed.
These reactions occur in the presence of strong bases and yield primary, secondary, and tertiary phosphines and phosphine
oxides.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1695–1702, September, 1998. 相似文献
20.
A. L. Klebanskii V. F. Gridina L. P. Dorofeenko A. F. Zhigach N. V. Kozlova L. E. Krupnova G. E. Zakharova N. I. Shkambarnaya 《Chemistry of Heterocyclic Compounds》1968,4(6):705-707
The coupling of dilithio-o-carborane with , -dichlorooligodimethylsiloxanes of type ClSi(CH3)2O[Si(CH3)2O]nSi(CH3)2Cl with n from 1 to 3 has been performed. At a molar ratio of the reagent of 11, the products of the reaction are a five-membered ring compound, 1, 3-o-carboranetetramethyldisiloxane and a cyclodimethylsiloxane, and at a ratio of the reagents of 12, a seven-membered ring compound, 1, 5-o-carboranehexamethyltrisiloxane, and a cyclodimethylsiloxane. Attempts to open the seven-membered o-carboranesiloxane ring thermally or with the aid of acidic catalysts were unsuccessful. Under the influence of nucleophilic reagents, cleavage of the C-Si bond takes place with the splitting away of a silicon atom from the o-carborane nucleus and the formation of an o-carbonate and a cyclodimethylsiloxane. 相似文献