1346508-93-7Relevant articles and documents
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.
Reductive aromatization of oxindoles to 3-substituted indoles
Mandal, Tirtha,Chakraborti, Gargi,Dash, Jyotirmayee
supporting information, (2020/06/21)
A practical and scalable approach for the synthesis of 3-substituted indoles is delineated via hydride nucleophilic addition to 3-substituted-2-oxindoles. The reaction proceeds through reductive aromatization involving indolinium ion intermediate. A wide range of 3-functionalized indoles have been synthesized. The method is employed for the synthesis of 3,3?-bis-indoles and a dimeric 3-indole derivative. Moreover, this protocol is used to obtain naturally occuring amino acid tryptamine.
Evaluating polymer-supported isothiourea catalysis in industrially-preferable solvents for the acylative kinetic resolution of secondary and tertiary heterocyclic alcohols in batch and flow
Guha, Nitul Ranjan,Neyyappadath, Rifahath M.,Greenhalgh, Mark D.,Chisholm, Ross,Smith, Samuel M.,McEvoy, Megan L.,Young, Claire M.,Rodríguez-Escrich, Carles,Pericàs, Miquel A.,H?hner, Georg,Smith, Andrew D.
supporting information, p. 4537 - 4546 (2018/10/17)
Polymer-supported Lewis base catalysts, based on the homogeneous isothioureas HyperBTM and BTM, have been synthesised and applied for the acylative kinetic resolution of secondary and tertiary heterocyclic alcohols. In batch, the use of industrially-preferable solvents was investigated, with dimethyl carbonate proving to be most generally-applicable. Significantly, the HyperBTM-derived immobilised catalysts were readily recycled, with no loss in either activity or selectivity. In addition to the kinetic resolution of secondary benzylic, propargylic, allylic and cycloalkanol derivatives, a range of 22 tertiary heterocyclic alcohols, based on privileged 3-hydroxyoxindole and 3-hydroxypyrrolidinone substructures, were resolved with up to excellent selectivity (s = 7-190). Finally, the immobilised isothiourea catalysts were applied in a packed bed reactor to demonstrate the first example of the kinetic resolution of tertiary heterocyclic alcohols in a continuous flow process. High selectivities were obtained for the resolution of 3-hydroxyoxindole derivatives in ethyl acetate (s up to 70); and for 3-hydroxypyrrolidinones derivatives in toluene (s up to 42).
Divergent and Orthogonal Approach to Carbazoles and Pyridoindoles from Oxindoles via Indole Intermediates
Mandal, Tirtha,Chakraborti, Gargi,Karmakar, Shilpi,Dash, Jyotirmayee
supporting information, p. 4759 - 4763 (2018/08/24)
The previously unexplored Grignard addition to oxindoles provides a regiospecific approach to 2- and 2,3-disubstituted indole derivatives in high yields via a one-pot aromatization driven dehydration pathway. This method allows a convenient preparation of diallyl indoles that are used as ring-closing metathesis (RCM) precursors for the orthogonal synthesis of pyrido[1,2-a]indoles and carbazoles. The synthetic utility of this method is illustrated by the synthesis of a microtubulin inhibitor and naturally occurring carbazole alkaloids.
Axial tri-tert-butylphosphane coordination to Rh2(OAc)4: Synthesis, structure, and catalytic studies
Tan, Jiantao,Kuang, Yi,Wang, Yi,Huang, Qingfei,Zhu, Jin,Wang, Yuanhua
supporting information, p. 3139 - 3147 (2016/10/09)
The introduction of strong σ-donor axial ligands to the Rh-Rh metal bond has been utilized as an effective way to provide new chemical reactivities to bimetallic dirhodium(II) complexes. In this report, Rh2(OAc)4 complexes with axial
Copper-catalyzed arylation of indolin-2,3-ones with arylboronic acids
Zhang, Jilei,Chen, Jiuxi,Ding, Jinchang,Liu, Miaochang,Wu, Huayue
supporting information; experimental part, p. 9347 - 9351 (2011/12/14)
A convenient and efficient Cu(OTf)2-catalyzed arylation of indolin-2,3-ones with arylboronic acids using cheap 1,10-phenanthroline hydrate as ligand was developed under air atmosphere, achieving 3-aryl-3-hydroxy-2- oxindoles in good to excellen
