63220-48-4Relevant articles and documents
Organocatalytic Asymmetric Synthesis of Cyclic Acetals with Spirooxindole Skeleton
Shikari, Amit,Mandal, Koushik,Chopra, Deepak,Pan, Subhas Chandra
supporting information, p. 58 - 63 (2021/11/09)
An organocatalytic asymmetric synthesis of cyclic acetal with spirooxindole skeleton has been developed via a domino reaction between isatin and γ-hydroxy enones. Bifunctional squaramide catalyst with adamantyl motif was found to be the most effective for the cascade reaction. With 10 mol% of the catalyst, the desired products were obtained in 1.8:1 to 9:1 diastereo- and 86% to >99% enantioselectivities from a range of substituted isatins and γ-hydroxy enones. (Figure presented.).
Acylation of oxindoles using methyl/phenyl estersviathe mixed Claisen condensation - an access to 3-alkylideneoxindoles
Gandhi, Thirumanavelan,Nagaraja, C. M.,Panyam, Pradeep Kumar Reddy,Rajeshwaran, Purushothaman,Sreedharan, Ramdas,Yadav, Saurabh
supporting information, p. 3843 - 3847 (2020/06/03)
Predominantly, aggressive acid chlorides and stoichiometric coupling reagents are employed in the acylating process for synthesizing carbonyl tethered heterocycles. Herein, we report simple acyl sources,viz. methyl and phenyl esters, which acylate oxindolesviathe mixed Claisen condensation. This straightforward protocol is mediated by LiHMDS and KOtBu and successfully applied to a wide range of substrates. It is a noteworthy transformation that skips the stepwise generation of enolates and acylation, and the reaction is performed at a moderate temperature with no side reactions. This protocol produces the first examples ofortho-substituents in an aryl ring flanked with electron-donating and electron-withdrawing substrates. Interestingly, robust organometallic ferrocenyl methyl ester cleaved under these conditions with ease. Furthermore, biologically important Tenidap's analog was synthesized by this protocol.
Palladium(II)/N-Heterocyclic Carbene Catalyzed One-Pot Sequential α-Arylation/Alkylation: Access to 3,3-Disubstituted Oxindoles
Reddy Panyam, Pradeep Kumar,Ugale, Bharat,Gandhi, Thirumanavelan
, p. 7622 - 7632 (2018/06/22)
Rationally designed fluorene-based mono- and bimetallic Pd-PEPPSI complexes were synthesized and demonstrated to be effective for the one-pot sequential α-arylation/alkylation of oxindoles. This streamlined approach offers efficient access to functionalized 3,3-disubstituted oxindoles in excellent yields (up to 89%) under mild reaction conditions.