1384117-33-2Relevant academic research and scientific papers
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.
, (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.
Me-BIPAM for the synthesis of optically active 3-aryl-3-hydroxy-2-oxindoles by ruthenium-catalyzed addition of arylboronic acids to isatins
Yamamoto, Yasunori,Miyaura, Norio,Yohda, Masaaki,Shirai, Tomohiko,Ito, Hajime
, p. 2446 - 2449,4 (2020/08/24)
A chiral O-linked C2-symmetric bidentate phosphoramidite (Me-BIPAM) was found to be efficient for the ruthenium-catalyzed addition of arylboronic acids to isatins. Asymmetric synthesis of 3-aryl-3-hydroxy-2- oxindoles by 1,2-addition of arylboronic acids to isatins was carried out in the presence of [RuCl2(PPh3)3]/(R,R)-Me-BIPAM and KF, resulting in an enantioselectivity as high as 90 % ee. It was found that the reaction with N-protected isatins proceeds with high yields and good enantioselectivities. The best protective groups on the nitrogen atom were different depending on the substituents on the aromatic ring. The use of a N-benzyl group resulted in excellent enantioselectivities in many substrates compared with other groups. Add it up: A chiral O-linked C2-symmetric bidentate phosphoramidite (Me-BIPAM) was found to be efficient for the ruthenium-catalyzed addition of arylboronic acids to isatins. Asymmetric synthesis of 3-aryl-3-hydroxy-2-oxindoles by 1,2-addition of arylboronic acids to isatins was carried out in the presence of [RuCl2(PPh 3)3]/(R,R)-Me-BIPAM and KF, resulting in an enantioselectivity as high as 90 % ee. Copyright
