Modular Phosphite–Oxazoline/Oxazine Ligand Library for Asymmetric Pd-Catalyzed Allylic Substitution Reactions: Scope and Limitations—Origin of Enantioselectivity
作者:Montserrat Diéguez、Oscar Pàmies
DOI:10.1002/chem.200701636
日期:2008.4.18
A library of phosphite-oxazoline/oxazine ligands L1-L15 a-h has been synthesized and screened in the Pd-catalyzed allylic substitution reactions of several substrate types. These series of ligands can be prepared efficiently from easily accessible hydroxyl amino acid derivatives. Their modular nature enables the substituents/configurations in the oxazoline/oxazine moiety, alkyl backbone chain and in
N-Arylcarbonylpseudoprolines as Tunable Chiral Derivatizing Agents for the Determination of the Absolute Configuration of Secondary Alcohols
作者:So-Yeong Han、Kihang Choi
DOI:10.1002/ejoc.201100209
日期:2011.6
chiral derivatizing agents, 3-arylcarbonyl-2,2-dimethyl-oxazolidine-4-carboxylic acids (N-arylcarbonylpseudoprolines), were prepared through a simple, short-step synthesis. The absoluteconfiguration of secondary alcohols can be assigned on the basis of the NMR spectroscopic chemical shift difference between diastereomeric pseudoproline esters. Preparation of more efficient agents was achieved simply