31541-32-9Relevant articles and documents
A general and efficient method to access tetracyclic spirooxindole derivatives
El Bouakher, Abderrahman,Massip, Stphane,Jarry, Christian,Troin, Yves,Abrunhosa-Thomas, Isabelle,Guillaumet, Grald
, p. 556 - 559 (2015)
An efficient, simple, and convenient synthetic procedure for the synthesis of tetracyclic spirooxindole derivatives, starting from N-protected isatins and 2-fluoropyridine, was successfully developed. It enables the facile formation of a new class of spirooxindoles in which the oxindole core is fused with various heterocycles at the C-3 position.
Scope, Limitations and Mechanistic Analysis of the HyperBTM-Catalyzed Acylative Kinetic Resolution of Tertiary Heterocyclic Alcohols**
Smith, Samuel M.,Greenhalgh, Mark D.,Feoktistova, Taisiia,Walden, Daniel M.,Taylor, James E.,Cordes, David B.,Slawin, Alexandra M. Z.,Cheong, Paul Ha-Yeon,Smith, Andrew D.
supporting information, (2021/11/16)
The full scope and limitations of the catalytic acylative kinetic resolution of a range of tertiary heterocyclic alcohols (78 examples, s up to >200) is reported under operationally-simple conditions, using low loadings of a commercially available Lewis basic isothiourea catalyst, HyperBTM (generally 1 mol %). The protocol is highly effective for the kinetic resolution of 3-substituted 3-hydroxyoxindole and α-substituted α-hydroxylactam derivatives bearing up to three potential recognition motifs at the stereogenic tertiary carbinol center. The full power of this methodology has been showcased through the synthesis of highly enantioenriched biologically-active target compounds in both enantiomeric forms. To provide further insight into the reaction mechanism, a detailed kinetic analysis of this Lewis base-catalyzed acylation of tertiary alcohols is reported using the variable time normalization analysis (VTNA) method.
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.
