ChemInform Abstract: Studies on the Chemistry of Isoindoles and Isoindolenines. Part 25. Procedure for the Preparation of 2‐Aryl‐2H‐isoindoles.

Abstract

1,2‐Di(bromomethyl)benzene (I) is coupled with the anilines (II) to produce the N‐arylisoindolenines (III) as the main products, together with minor amounts of the dimers (IV).

Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXII [1] Elektrophile Substitutionsreaktionen von 2-Aryl-2H-isoindolen mit Trifluoressigsäureanhydrid / Studies on the Chemistry of Isoindoles and Isoindolenines, XXXII [1] Electrophilic Substitution Reactions of 2-Aryl-2H-isoindoles with Trifluoroacetic Anhydride

“…C 62,08 H 5,12 N 4,54. IR (KBr): v = 1610, 1560, 1205, 1145, 1125 ]Aceton): <3 = 2,40 (s; 6H, CH 3 -2', CH 3 -5'), 6,00 (d, 7 U = 2,0 Hz; 2H, H-l), 7,50 (m;7H,9,90 (t,7 3 (19), 204 (17), 111 (13), 103 (18), 77 (18), 49 (18).…”

The Curtin–Hammett principle in action: 1-amino-3H-isoindole in cycloaddition reactions

“…Isoindoles are promising active biological materials 1,2 with interesting spectral properties and are the subject of study for important theoretical questions, such as: aromaticity, tautomerism [3][4][5][6][7][8] and represent the important source of the reactive compounds and synthons used for cycloaddition reactions, [9][10][11][12][13][14] the study of the organic reactions mechanisms, new rearrangements [15][16][17][18][19][20][21] and the creation of new colouring agents. [22][23][24] The most typical reaction for simple isoindole systems is the Diels-Alder reaction but previously this reaction was associated only with isoindoles prevalently in the isoindole tautomeric form.…”

New tandem cyclo‐ and/or addition reactions between N‐arylisoindolines with benzyne and dimethyl acetylenedicarboxylate

“…Herein, we report the cycloaddition reactions of N ‐arylisoindolines 4a , 4b , 4c , 4d with benzyne (dehydrobenzene, 2 ), which was generated by diazotization of 1,2‐anthranilic acid [11, 16–19]. We chose N ‐arylisoindolines 4a , 4b , 4c , 4d bearing electron donating and withdrawing substituents on the benzene ring, to examine their effect on the course of reaction.…”

“…Autoxidation of 10a is reported to give ring opening, not closure to 8a [22]; thus, we exclude 10a , 10b , 10c , 10d as intermediates in our pathways leading to 8a , 8b , 8c , 8d . Published syntheses of isoindoles from isoindolines proceed via N‐ oxidation, followed by O ‐acylation and elimination [17, 23]. However, benzyne is reported to oxidize dihydropyridines to pyridines [24], presumably by a hydrogen‐transfer mechanism like a diimide reduction.…”

“…Benzenediazonium carboxylate was prepared by the procedure described in [16–19]. Under nitrogen atmosphere, 6 mmol of benzyne ( 2 ) precursor was slowly added to the stirred and refluxed solutions of 4a , 4b , 4c , 4d (2 mmol) in dry acetonitrile (250 mL) for 1 h. The reaction mixture was refluxed till the consumption of the starting materials was completed (reaction progress monitored by TLC analysis) in 4–10 h. The solvent was concentrated and the residue was filtered off.…”