Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

Abstract

SummaryA direct one-pot base-induced alkenylation of indolin-2-ones has been developed by using 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles. Different bases such as MeONa, NaH and t-BuONa have been used to optimize the reaction conditions to obtain the desired product. NaH in THF was found to be the most suitable for the alkenylation of indolin-2-ones. Reaction in the presence of other bases led to the formation of 1-aryl-3-methoxy/methylthio-5H-dibenzo[d,f][1,3]diazepin-6(7H)-ones. Quantum chemical calculations have been performed to explain the nature of the weak noncovalent interactions operating in the supramolecular architectures of alkenylated indoline-2-ones and to explain the relative stability of one of the tautomers with respect to the others.

Non-Palladium-Catalyzed Approach to the Synthesis of (E)-3-(1,3-Diarylallylidene)Oxindoles

“…In all previous methods palladiumcatalyzed reactions were the key reactions, which greatly limited the range of products to which these procedures could be applied. A few non-palladium-catalyzed approaches to 3-allylideneoxindoles have been reported, but they cannot be applied to the synthesis of 3-(1,3-diarylallylidene)oxindoles [11,12]. Therefore, we attempted to develop a novel synthetic method for 3-(1,3-diarylallylidene)oxindoles with a wide substrate scope using commercially available or easily accessible reagents, and not involving palladium-catalyzed reactions.…”

Synthesis of Dibenzo[d,f][1,3]Diazepines via Elemental Sulfur-Mediated Cyclocondensation of 2,2′-Biphenyldiamines with 2-Chloroacetic Acid Derivatives

“…Benzodiazepines are important structural units found in a variety of biologically active agents, including natural products (e.g., streptocarbazoles A and B) and major drugs (e.g., anxiolytics, such as cloxazolam, ketazolam, flumazenil, clobazam, delorazepam, alprazolam, etc., the anesthetic midazolam, the tranquillizer ethyl loflazepate) . The prevalence of the dibenzo­[ d , f ]­[1,3]­diazepine motif in medicinally relevant compounds, dyes, catalysts, , MOFs (metal–organic frameworks), , and organic electronics materials (Figure ) has inspired the development of many novel methods for their preparation. − Thus, iodine-mediated coupling of 2,2′-diaminobiphenyl with aldehydes, cyclocondensation of silylamines with CO 2 , the reaction of 2,2′-diaminobiphenyl with bis­(isothiocyanate), the titanacarborane monoamide-catalyzed reaction of diamines with carbodiimides, cyclization reactions of 3-methyleneoxindoles with 2-cyano-2-(3,4-dihydronaphthalen-1­(2 H )-ylidene)­acetate, and indolin-2-ones with 4-methylthio-2 H -pyran-2-one-3-carbonitriles , have been recently reported. However, there is a limited number of protocols for assembling 2-carboxy-substituted dibenzo­[1,3]­diazepine derivatives that hold promise for materials science and medicinal chemistry.…”