Multiple Aryne Insertions into Oxindoles: Synthesis of Bioactive 3,3-Diarylated Oxindoles and Dibenzo[b,e]azepin-6-ones

Abstract

An aryne insertion cascade reaction on oxindoles has been observed and constitutes a convenient "one pot" preparation of bioactive di- and triarylated oxindoles in good yields under mild conditions. A temperature controlled "reaction switch" enables ready access to dibenzo[b,e]azepin-6-one derivatives employing the same reaction regime. This tactic has been extended to a short synthesis of potent antiulcer agent darenzepine.

Transition-metal-free α-arylation of oxindoles via visible-light-promoted electron transfer

“…In contrast, transition-metal-free arylations were only limited in the S N Ar reaction of oxindoles with electron-deficient nitroaryl fluorides12 or oxidative nucleophilic addition of oxindoles to nitroarenes 13. In addition, Srihari and coworkers reported a multiple aryne insertion approach to construct 3,3-diarylated oxindoles 14. Even though the above achievements have been made, the direct α-arylation of oxindoles with inactive aryl halides under transition-metal-free conditions remains a challenge.…”

Dibenzo[b,e]azepin-6-ones and Seven-Membered Sultam Derivatives: Convenient Synthesis via Palladium-Catalyzed Regioselective Intra­molecular Heck Reaction and Application towards Drug-Like Small Molecules

“…For example, dibenzoazepinone derivatives were synthesized via Schmidt rearrangement followed by Wittig-Horner olefination reactions, 4 tandem reductionlactamization sequence, 8 and regio-and chemoselective direct benzylation reaction. 9 Recently, Mehta and co-workers 10 have reported the synthesis of darenzepine (A), an antiulcer agent and a scaffold of dibenzo [b,e]azepin-6-one series via temperature controlled aryne insertion cascade reaction on substituted oxindole (Scheme 1). Besides, syntheses of benzazepines are also reported.…”

PdCl2/CuCl2/Bi(OTf)3‐promoted Construction of Sulfonyl Dibenzooxabicyclo[3.3.1]nonanes and Arylnaphthalenes via Intramolecular Annulation of Sulfonyl o‐Allylarylchromanones

“…Among these diverse kinds of reaction routes, a number of synthetic efforts have attempted to control one factor or variant to generate different products with approximate or distinct skeletons in recent reports. These adjusting factors included temperature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] catalyst, [15][16][17][18][19][20][21] additive (e. g. ligand, [22][23][24][25] base [26][27] and reagent [28][29][30][31] ) and solvent. [32][33][34][35] On the basis of the abovementioned investigations, we found that controlling the temperature change is a simple, economical and direct protocol for affecting the formation of different products in comparison with other variables.…”

“…[3] Mehta et al found that the refluxing temperature can force conversion from in situ generated N,3,3-triarylated oxindoles to dibenzo [b,e] azepinones during multiple aryne insertions into the oxindole process (eq 4). [4] Very recently, we have reported the temperature-controlled synthesis of azaaryl aurones and flavones via desulfonylative condensation of α-sulfonyl o-hydroxyacetophenones and 2formyl azaarenes (Scheme 2). [5] Based on the above literature search for temperature-controlled synthetic methods, and continuing our previous research into temperature-adjusted conversion from aurones to flavones, herein, we present a novel PdCl 2 /CuCl 2 /Bi(OTf) 3 -promoted construction of tetracyclic sulfonyl dibenzooxabicyclo[3.3.1]nonanes and bicyclic arylnaphthalenes via an intramolecular domino Wacker-type annulation of sulfonyl o-allylarylchromanones under 25°C/5 h and 65°C/15 h conditions, respectively.…”