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1
Content available Nukleofilowe podstawienie wodoru w nitroarenach. Proces analogiczny i komplementarny do podstawienia elektrofilowego
Mąkosza M.
Wiadomości Chemiczne
|
2011
|
[Z] 65, 9-10
795-819
EN
Nucleophiles add to electron-deficient arenes, also those containing halogens, initially in positions occupied by hydrogen to form óH adducts. This addition is faster than addition in similarly activated positions occupied by halogens. Formation of the óH adducts is a reversible process, thus they dissociate and slower addition in positions occupied by halogens results in formation of óH adducts followed by fast departure of X– to form products of nucleophilic substitution of halogen, SNAr. In the review it is shown that there are a few ways for fast further conversion of initially formed óH adducts into products of nucleopilic substitution of hydrogen such as oxidative substitution, vicarious substitution, etc. Since formation of óH adducts is faster than óH adducts and the former undergo fast transformations into products of nucleophilic substitution of hydrogen we should accept than this is the major, primary reaction whereas conventional nucleophilic substitution of halogens, SNAr reaction “ipso” substitution is just a secondary process. In modern textbooks only SNAr reactions are discussed whereas nucleophilic substitution of hydrogen is not mentioned, thus it is necessary to introduce proper corrections in textbooks and teaching of this chapter of chemistry of arenes.
2
Evaluation of Electrophilic Activities of Substituted Nitroarenes in the VNS Reaction with Secondary and Tertiary Carbanions
Błażej S., Wileńska B., Voynova N. S., Mąkosza M.
Polish Journal of Chemistry
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2008
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Vol. 82, nr 10
2017-2030
EN
Relative electrophilic activities of substituted nitroarenes in the vicarious nucleophilic substitution (VNS) reaction with carbanion of chloromethyl p-chlorophenyl and bromo - methyl phenyl sulfones, 1 and 2, were determined via competitive experiments. The results are in good agreement with relative activities determined earlier in the competitive experiments with carbanion of chloromethyl phenyl sulfone 3 confirming reliability of these data. On the other hand, analogous competitive experiments with tertiary carbanions of chloroform and 1-chloroethyl phenyl sulfone gave results much affected by steric effects thus the VNS reaction with these carbanions can not be used for evaluation of electrophilic activities of nitroarenes.
3
Trifluoromethylation of Carbonyl Compounds with Trifluoromethyltrimethylsilane (Ruppert Reagent) Promoted by Triphenyldifluorostannates
Borkin D., Loska R., Mąkosza M.
Polish Journal of Chemistry
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2005
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Vol. 79 / nr 7
1187-1191
EN
Nucleophilic trifluoromethylation of aromatic aldehydes and ketones with trifluoromethyltrimethylsilane is initiated with KF/n-Bu3MeN+HSO4 /Ph3SnF cocatalytic system in CH2Cl2 or with K[Ph3SnF2] in DMF.
4
Oxidative Nucleophilic Substitution of Hydrogen in nitroarenes. A Short Review
Mąkosza M., Paszewski M.
Polish Journal of Chemistry
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2005
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Vol. 79 / nr 2
163-178
EN
Recent results of oxidative nucleophilic substitution of hydrogen in nitroarenes with carbon, nitrogen, oxygen etc. nucleophiles and discussion of oxidants used in these reactions are presented.
5
Phase Transfer Catalyzed Reactions of Chloroform with Methacrylic Esters
Fedoryński M., Błażejczyk A., Mąkosza M.
Polish Journal of Chemistry
|
2003
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Vol. 77 / nr 5
709-717
EN
Chloroform reacts with an excess of methyl methacrylate in the presence of 50% aq NaOH and benzyltriethylammonium chloride (TEBA) as a catalyst (phase transfer catalysis, PTC) to give a mixture of dichlorocarbene and trichloromethyl anion adducts, 1 and 2, respectively. These additions proceed as parallel processes, there is a slow conversion of 2_ 1, which proceeds as an intramolecular process.
6
On animation and Diazotization of Azulene and Its Derivatives
Mąkosza M., Osiński P. W., Ostrowski S.
Polish Journal of Chemistry
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2001
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Vol. 75, nr 2
275-281
EN
A practical procedure for synthesis of 6-aminoazulene (3) via Vicarious Nucleophilic Substitution of Hydrogen (VNS) amination of azulene with 4-amino-1,2,4-triazole is reported. Amination with use of N,N,N-trimethylhydrazinium iodide (TMHI) of more electrophilic azulene derivatives, substituted at position 1- with CN or COPh group, afforded a mixture of 4-, 6-, and 8-aminoazulenes. Attempts to convert 6-aminoazulene (3) into diazonium salt failed, only formation of small quantities of the "auto-coupling" product, 1-(azulen-6-ylazo)-azulen-6-yl-amine, was observed.
7
Reactions of Chlorinated Pyrimidine Derivatives with Carbanions Bearing Nucleophugal Groups at the Carbanionic Center
Mąkosza M., Ostrowski S.
Polish Journal of Chemistry
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2000
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Vol. 74, nr 10
1355-1355
EN
Reactions of chloro-, dichloro-, and trichloropyrimidines with carbanions bearing leaving groups at the carbanionic center are described. 2-Chloropyrimidine and 2,4-dichloropyrimidine react at low temperature with trihalomethyl carbanions to give covalent sigma-adducts and low yield of the Vicarious Nucleophilic Substitution of Hydrogen (VNS) products. 4,5,6-Trichloropyrimidine in the reactions with carbanions (–CH(X)SO2Tol, CBr-3) or other nucleophiles (t-BuO–, NH3) gives diverse substituted products of chlorine while in the reaction with CC-3 anion the VNS product in small amount.
8
Vicarious Nucleophilic Substitution of Hydrogen in 2,4-Dinitroanilines and Cyanonitroanilines
Mąkosza M., Voskresensky S., Białecki M., Kwast A.
Polish Journal of Chemistry
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1999
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Vol. 73, nr 12
1969-1977
EN
Orientation of the VNS reaction in nitroaniline derivatives is mostly governed by the conjugation between the nitro groups and the amino group, which could be also deprotonated under the reaction conditions.
9
Oxidative Nucleophilic Substitution of Hydrogen in Nitroarenes : a Short Review
Mąkosza M., Staliński K.
Polish Journal of Chemistry
|
1999
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vol. 73 nr 1
151-161
EN
Selected examples of oxidative nucleophilic aromatic substitution in nitroarenes are discussed with emphasis on the authors results. Generalization of this process is attempted.
10
Influence of conjugation on orientation in substituted nitropyridines: Vicarious Nucleophilic Substitution of Hydrogen with chloromethyl phenyl sulfone
Mąkosza M., Ludwiczak S.
Polish Journal of Chemistry
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1998
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Vol. 72, nr 7
1168-1172
EN
2-Hydroxy- and 2-mercapto-5-nitropyridines as well as their O- ( and S-) substituted derivatives enter Vicarious Nucleophilic Substitution of Hydrogen (VNS) with chloromethyl phenyl sulfone. The orientation of the substitution can be controlled by varying the O- (or S-) substituent. The results of VNS in 4-methoxy-3-nitropyridine and 3-methoxy-2-nitropyridine are also reported.
11
Ambiphilic reactivity of 2,4-dinitrobenzyl p-tolyl sulfone carbanion
Mąkosza M., Mathur S.N., Białecki M.
Polish Journal of Chemistry
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1998
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Vol. 72, nr 7
1198-1201
EN
Carbanions of 2,4-dinitrobenzyl p-tolyl sulfone (3a) and 5-chloro-2,4-dinitrobenzyl p-tolyl sulfone (3b) behave as ambiphilic reagents able to react with nucleophiles and electrophiles. The reaction course depends on the type of the reagent and of the base used in the reaction.
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