The Use of 2,2,2-Trichloro-1-Arylethanones as Benzoylating Agents

The preparation of several amides and hydrazides from the reaction of the title compounds with different nitrogen nucleophiles is shown to be a general high-yield conversion of synthetic utility.     

Reactions of Aroxy- and Arylsulfanylacetic Acids and Their Esters with N-(2,2,2-Trichloro-1-hydroxyethyl)sulfonamides and -carboxamides

C-Amidoalkylation of aroxy- and arylsulfanylacetic acids and their methyl esters was effected by reaction with N-(2,2,2-trichloro-1-hydroxyethyl)sulfonamides and -carboxamides in the presence of methane- or trifluoromethanesulfonic acids as catalyst and solvent. The process is regioselective, and the substitution occurs at the para-position with respect to the heteroelement-containing group.     

Alkyl 2,2,2-Trifluoroethanesulfonates (Tresylates): Elimination-Addition vs Bimolecular Nucleophilic Substitution in Reactions with Nucleophiles in Aqueous Media(1)

Alkyl 2,2,2-trifluoroethanesulfonate esters (tresylates), ROSO(2)CH(2)CF(3), react with aqueous base (pH >/= 9) to give the (alkoxysulfonyl)acetic acid, ROSO(2)CH(2)COOH; with the further addition of either a primary or secondary amine or of an alkanethiol, the product is the either the corresponding amide, ROSO(2)CH(2)C(O)NR(1)R(2), or a mixture in which the ketene dithioacetal, ROSO(2)CH=C(SR(1))(2), or the thioorthoester, ROSO(2)CH(2)C(SR(1))(3), may predominate. Kinetic and product studies are consistent with the following: (a) the reaction of tresylates with water is the normal sulfonic ester hydrolysis and (b) reaction with hydroxide is an (E1cB)(rev) process with loss of HF to yield the alkyl 2,2-difluoroethenesulfonate, ROSO(2)CH=CF(2), which rapidly yields the observed products. Benzyl 2,2,2-trifluoroethyl sulfone reacts analogously. The relationship between these observation with small molecules and those of earlier workers with tresyl agarose is discussed.     

Reactions of Alicyclic Epoxy Compounds with Nitrogen-Containing Nucleophiles

The review considers reactions of alicyclic epoxy compounds and their analogs with nitrogen-containing nucleophilic reagents, such as amines, azides, hydrazines, etc., biological aspects of these reactions, and properties of amino alcohols which are practically important organic products and synthons. Reaction mechanisms, including radical and radical ion reaction paths, the results of quantum-chemical studies, stereo- and regioselectivity aspects, and activation of epoxy substrates with achiral and chiral catalysts are discussed. The formation of nitrogen-containing heterocyclic systems via opening of the oxirane ring is described.     

The Synthesis of Sulfinylphthalimides and their Reactions with Some Nucleophiles in Dioxane

Abstract

In this study, some N-(p-substituted-arylsulfinyl)phthalimides (1a–1e) were synthesized. The synthesized compounds were examined with respect to their substitution reactions with sodium ethoxide, sodium methoxide, methylamine, and t-butylamine in dioxane. The substituent effect was investigated at 30.0 ± 0.1 °C. The activation entropy was also studied, and negative ΔS^≠ values were obtained. Configuration inversions were observed in the substitution reactions. This result is in conformity with the S_N2 mechanism.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Characterization of -(p-Substituted-arylsulfinyl)phthalimides 1a–b.]     

Reactions of alkylthiochloroacetylenes with O,N-and S,N-containing bifunctional nucleophiles

Conclusions Reaction of alkylthiochloroacetylenes with N-alkyl-N-(2-hydroxyethyl)amines proceeds with formation of N-alkyl-N-(2-hydroxyethyl) amides of alkylthioacetic acids, and reaction with 2-hydroxyethyl- and 2-mercaptoethylamine results in 2-(alkylthiomethyl)-4,5-dihydro-1,3-oxazoles and the hydrochlorides of alkylthioethynyl(2-aminoethyl) sulfides respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 616–619, March, 1988.     

Reactions of Nucleophiles with Nitroarenes: Multifacial and Versatile Electrophiles

In this overview, it is shown that there are many initial reactions between nitroarenes and nucleophiles: addition to the electron‐deficient ring at positions occupied by halogen and hydrogen atoms, addition to the nitro group, single‐electron transfer (SET), and other types of initial reactions. The resulting intermediates react further in a variety of ways to form products of nucleophilic substitution of a halogen atom (S_NAr), a hydrogen atom (S_NArH), and others. Many variants of these processes are briefly discussed, particularly in relation of rates of the initial reactions and further transformations.     

Reactions of Chlorosulfanyl Derivatives of Cyclobutanones with Different Nucleophiles

The reactions of 3‐chloro‐3‐(chlorosulfanyl)‐2,2,4,4‐tetramethylcyclobutan‐1‐one ( 2 ) with N, O, S, and P nucleophiles occur by substitution of Cl at the S‐atom. Whereas, in the cases of secondary amines, alkanols, phenols, thiols, thiophenols, and di‐ and trialkyl phosphates, the initially formed substitution products were obtained, the corresponding products with allyl and propargyl alcohols undergo a [2,3]‐sigmatropic rearrangement to give allyl and allenyl sulfoxides, respectively. Analogous substitution reactions were observed when 3‐chloro‐3‐(chlorodisulfanyl)‐2,2,4,4‐tetramethylcyclobutan‐1‐one ( 3 ) was treated with N, O, and S nucleophiles. The reaction of 3 with Et₃P led to an unexpected product via cleavage of the S? S bond (cf. Scheme 13). In the reactions of 2 with primary amines and H₂O, the substitution products react further via elimination of HCl to yield the corresponding thiocarbonyl S‐imides and the thiocarbonyl S‐oxide, respectively. Whereas the latter could be isolated, the former were not stable but could be intercepted by MeOH (Scheme 4) or adamantanethione (Scheme 5). The structures of some of the substitution products were established by X‐ray crystallography.     

Reactions of α-Phosphoryl-α-haloacetaldehydes with Difunctional Nucleophiles

Reactions of phosphorylated α-haloacetaldehydes with difunctional nitrogen-, oxygen-, and sulfur-containing nucleophiles were performed with a view to synthesize C-phosphorylated heterocyclic compounds.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 520–523.Original Russian Text Copyright © 2005 by Asadov, Burangulova, Guseinov.     

Regioselectivity of Reactions of Nitrogen and Carbon Nucleophiles with Coumarin Derivatives

Abstract

Reaction of various 3‐substituted coumarins with nitrogen and carbon nucleophiles appears to involve, in all cases examined, exclusive, direct substitution at the exocyclic C‐1′ electrophilic center.     

Reactions of Methyl 4-Aminofurazan-3-carboximidate with Nitrogen-Containing Nucleophiles

Methyl 4-aminofurazan-3-carboximidate reacts with aromatic amines and hydrazines to give the corresponding amidines and amidrazones. The reaction of the title compound with o-phenylenediamine yields 3-amino-4-(2-benzimidazolyl)furazan, and with acylhydrazines N²-acyl-4-aminofurazan-3-carbohydrazides are formed. The latter undergo thermal intramolecular cyclization with formation of 3-amino-4-(1,2,4-triazol-3-yl)furazan derivatives containing various substituents in position 5 of the triazole ring.     

Rhodium-catalyzed Asymmetric Ring-opening Reactions of N-Boc-azabenzonorbornadiene with N-Substituted Piperazine Nucleophiles

Asymmetric ring‐opening reactions of N‐Boc‐azabenzonorbornadiene with N‐substituted piperazine nucleophiles in the presence of 5 mol% of [Rh(COD)Cl]₂ and 10 mol% of chiral ligand, (R,S)‐PPF‐P‐t‐Bu₂, gave the corresponding 1,2‐diamine product in moderate to excellent yields (up to 95%) with reasonable enantiomeric excesses (up to 70% ee). The results showed that the nature of ligands had significant influence on the yields and the enantiomeric excesses.     

Reactions of 2,2,2-trifluorodiazoethane with carbon-nitrogen and carbon-oxygen multiple bonds

2,2,2-Trifluorodiazoethane reacts with trifluoroacetonitrile in the dark at room temperature to give a 2-(2,2,2-trifluoroethyl)-4, 5-bis(trifluoromethyl)triazole, the 1,2,3-triazole structure being preferred to the 1,2,4-isomer on the basis of the ¹⁹F n.m.r. spectrum. The diazoethane reacts more slowly with trichloroacetonitrile, again forming the N-alkylated triazole even in the presence of an excess of the nitrile. No identifiable adduct resulted with acetonitrile. Hexafluoroisopropyl-ideneimine is first N-alkylated and then undergoes addition to form 1-(2,2,2-trifluoro-1-trifluoromethyl)ethyl-4,5-bis(trifluoromethyl)-?-1,2,3-triazoline, but N-methylhexafluoroisopropylideneimine failed to react. Trifluoroacetaldehyde and trichloroacetaldehyde give mixtures of the ketone (formed by insertion of the CF₃CH group into the aldehyde CH bond) and the $\text{cis}$- and $\text{trans}$-oxirans, apparently $\text{via}$ a β-hydroxydiazoalkane.