The catalytic enantioselective diorganozinc additions to cyclic diketones including pyrazolin‐4,5‐diones and isatins have been developed. In the presence of morpholine‐containing chiral amino alcohol ligand, the corresponding chiral cyclic tertiary alcohols were produced in good to excellent yields (up to 97 %) and enantioselectivities (up to 95 % ee). The notable feature of this protocol includes
Scope, Limitations and Mechanistic Analysis of the HyperBTM‐Catalyzed Acylative Kinetic Resolution of Tertiary Heterocyclic Alcohols**
作者:Samuel M. Smith、Mark D. Greenhalgh、Taisiia Feoktistova、Daniel M. Walden、James E. Taylor、David B. Cordes、Alexandra M. Z. Slawin、Paul Ha‐Yeon Cheong、Andrew D. Smith
DOI:10.1002/ejoc.202101111
日期:2022.1.11
isothiourea HyperBTM catalyzes the acylative kinetic resolution of a wide range of tertiary heterocyclic alcohols under mild conditions with high selectivity. The synthetic utility of the methodology has been demonstrated with the preparation of two bioactive targets. Kinetic analysis reveals a fractional reaction order with respect to the alcohol concentration.
Kinetic Resolution of Tertiary Alcohols: Highly Enantioselective Access to 3-Hydroxy-3-Substituted Oxindoles
作者:Shenci Lu、Si Bei Poh、Woon-Yew Siau、Yu Zhao
DOI:10.1002/anie.201209043
日期:2013.2.4
Enantioselective: The first highlyenantioselectivekineticresolution of 3‐hydroxy‐3‐substituted oxindoles has been developed through oxidative esterification catalyzed by a N‐heterocyclic carbene (see picture). This method uses a simple procedure and provides 3‐hydroxy‐oxindoles with various substituents at the 3‐position in excellent enantiopurity. S=selectivity.