Anilide anions

There is little mention in the literature of the use of amide salts in substitution reactions on chlorophosphazene precursors. The anilide anion was shown to be a powerful nucleophile in substitution reactions on various trimer derivatives, but investigations of such reactions with the high polymer have not been reported.22 Where strong nucleophiles (such as amide salts) with low steric requirements are employed, the usual pentacoordinate transition state (Scheme 1), may be a viable reaction intermediate which can undergo alternative modes of decomposition, perhaps involving chain cleavage and/or cross-linking. 

Amination of aromatic nitro compounds is a very important process in both industry and laboratory. A simple synthesis of 4-aminodiphenyl amine (4-ADPA) has been achieved by utilizing a nucleophilic aromatic substitution. 4-ADPA is a key intermediate in the rubber chemical family of antioxidants. By means of a nucleophibc attack of the anilide anion on a nitrobenzene, a o-complex is formed first, which is then converted into 4-nitrosodiphenylamine and 4-nitrodiphenylamine by intra- and intermolecular oxidation. Catalytic hydrogenation finally affords 4-ADPA. Azobenzene, which is formed as a by-product, can be hydrogenated to aniline and thus recycled into the process. Switching this new atom-economy route allows for a dramatic reduction of chemical waste (Scheme 9.9).73 The United States Environmental Protection Agency gave the Green Chemistry Award for this process in 1998.74... 

Intramolecular examples of photostimulated SRN1 reactions implying excited anions with a demonstrated chain mechanism have been reported as in the case of anilide anions and JV-acyl benzylamines used as precursors of oxindoles and isoquinolines [129]. 

Substituent (X) Phenoxide anion Anilide anion Anilinium cation ... 

Mulliken Charges and Overlap Populations for Substituted Anilide Anions... 

Amide hydrolysis at alkaline pH involves a tetrahedral anionic intermediate, which was mimicked by the transition state analogue [49], an /V-aryl arylphosphonamidate, appropriately related to substrate anilide [50] (Fig. 18) (Appendix entry 2.8). 

In conclusion, the bis-barium complex of 17 catalyzes the ethanolysis of anilide and ester substrates endowed with a distal carboxylate anchoring group (Table 5.7). The catalyst shows recognition ofthe substrate, induces fairly high reaction rates with catalytic turnover, and is subjected to competitive inhibition by carboxylate anions, as... 

A variety of five-membered nitrogen heterocycles can be prepared efficiently by inter- or intramolecular addition/cyclizations of sulfonamide anions with alkynyliodonium salts. The intermolecular variant employs the combination of the amides 172 or anilides 174 with propynyl(phenyl)iodonium triflate (Scheme 65) [131,132]. The yield of dihydropyrroles 173 in this cyclization is extremely sensitive to the nature of the protective group P the tosyl group in 172 proved... 

Anilide 4 is lithiated selectively in ortho-position to the pivaloyl amide group.4 5 The organolithium species is generated by reaction of 4 with two equivalents of n-butyllithium below 5 °C in MTBE, since the amide proton is also acidic and is deprotonated to yield resonance-stabilized anion IS before the ort/zo-lithiation of the aromatic system with the second equivalent of n-butyllithium takes place. The resulting organolithium species 16 then undergoes nucleophilic attack of ester 176 to give dianion 18. 

An anionic ortho-Fries rearrangement has been used to make BINOL derivatives.194 2.3.2.1.5 Anilides and A-aryl carbamates... 

Although the mechanism of this reaction has yet to be fully established certain of its aspects have been defined. The intermediacy of the anion 269 is very probable, particularly since a solid which is presumably the intermediate (269 R = CgHs) has been isolated from the reaction of anilide ion with p-toluenesulphonyl azide. In support of the structural assignment this solid gave a mixture of phenyl azide (40%) and aniline when heated. The reaction sequence has been summarized as shown in equation (139). 

In ethanol, the 31,850 cm maximum (A) is reduced to a shoulder near 33,000 cm. Whereas in heptane a normal "Weller shift" of fluorescence indicating Intramolecular proton transfer is observed, in alcohols we note a fluorescence band at higher frequency with a maximum at 23,800 cm. The latter is due to the anion (D) and corresponds to the absorption maximum of D at 29,400 cm The intensity of this emission increases with increasing pH and remains constant above pH = 9 (in ethanol). The anilide of 2-methoxy benzoic acid shows a ultraviolet fluorescence that was too weak to be recorded (21). Low quantum efficiency may, therefore, be the reason that the fluorescence of C has not been detected. The only evidence of the presence of C is the close similarity of the absorption spectra of SAN and the methoxy derivative in ethanol (21). 

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