A General Amination Method Based on the Addition of Polyfunctional Arylmagnesium Reagents to Functionalized Arylazo Tosylates

Abstract

A one‐pot reaction sequence consisting of a Grignard reaction, allylation, and reduction provides new functionalized diarylamines in good yields (see scheme, Ts=toluene‐4‐sulfonyl, NMP=N‐methylpyrrolidine, TFA=trifluoroacetic acid). In the first step azoaryl tosylates, which are readily obtained from aromatic amines, are treated with a myriad of functionalized organomagnesium compounds.

Synthesis of amines by the electrophilic amination of organomagnesium, -zinc, -copper, and -lithium reagents

“…81 Arylazo tosylates which can be prepared in a two step-sequence consisting of a diazotation and tosylation of the resulting diazonium tetrafluoroborates, have been used as synthetic equivalents of the electrophilic arylamino synthon in the electrophilic amination of polyfunctional arylmagnesium reagents. 82 Polyfunctional diarylamines can be prepared by the addition of functionalized arylmagnesium reagents to functionalized arylazo tosylates, followed by in situ allylation and reductive workup (Scheme 17). …”

Metalated heterocycles in organic synthesis: Recent applications

“…167 Another example is the addition of a 1-carboxylated 2-indolylmagnesium chloride, generated by treatment of the corresponding iodide with isopropylmagnesium chloride, to arylazotosylates. 168 2-Furylmagnesium bromide, obtained from 2-furyllithium by a lithium/magnesium exchange using magnesium bromide, has been used as nucleophile in substitution reaction of allyl acetoxides 169 and in addition reactions to the nucleus of chiral pyridinium salts. 170 However, (74) has been generated from the corresponding 2-iodofurane by the usual treatment with isopropylmagnesium chloride, and used in an iron-catalyzed coupling reaction to aroyl cyanide 75 at -20 ºC to give the ketone 76 (Scheme 24).…”

Simple Molecules, Highly Efficient Amination

“…Arylazo p -tolyl sulfones 26 react under mild conditions with various polyfunctional arylmagnesium halides, and allylation of the resulting addition products, followed by treatment with zinc, provides polyfunctionalized diarylamines in good yield as shown in Table 1.5 . Aliphatic magnesium halides are also aminated [39] .…”