Synthesis of Chiral Hydantoins and Thiazolidinediones
<i>via</i>
<scp>Iridium‐Catalyzed</scp>
Asymmetric Hydrogenation
作者:Yu Nie、Jing Li、Qianjia Yuan、Wanbin Zhang
DOI:10.1002/cjoc.202100809
日期:2022.4
Herein, we report an iridium-catalyzed asymmetric hydrogenation of hydantoin and thiazolidinedione derived exocyclic alkenes using our developed BiphPHOX as a ligand. The transformation shows good functional group tolerance, and gives the hydrogenated products with excellent yields (up to 99%) and enantioselectivities (up to 98% ee). A gram-scale reaction was also carried out, and provided the hydrogenated
Case Studies in Process Screening and Optimization Utilizing a New Automated Reactor−Analysis System
作者:Owen W. Gooding、Thomas Lindberg、Wendy Miller、Edward Munyak、Lanchi Vo
DOI:10.1021/op0001077
日期:2001.5.1
The application of a new automated workstation for conducting solution-phase reactions in parallel during chemical process development is described. The fully automated reactor-analysis system is capable of reagent/reactant addition, temperature and agitation control, and sample extraction/quench/injection for online HPLC analysis. Both precision and accuracy of the fluidic delivery and sampling systems were measured through the use of standard ultraviolet chromophore solutions in conjunction with HPLC analysis. Agitation efficiency was evaluated using a phase-transfer catalysis reaction known to be rate-dependent on stirring frequency. Chemistry cases examined included several single and multistep reactions studied to identify the best reagent/solvent combinations (screening) and optimal levels of continuous variables such as temperature, concentration, and stoichiometry (optimization), A multistep route to a chiral substituted imidazolidin-2-one was developed from initial route scouting through reaction condition screening, optimization, and scale-up. Reactions performed included alkylation, reduction, oxidation, reductive amination, displacement, and cyclization.