141271-50-3Relevant academic research and scientific papers
Theoretical and Experimental Optimization of a New Amino Phosphite Ligand Library for Asymmetric Palladium-Catalyzed Allylic Substitution
Magre, Marc,Biosca, Maria,Norrby, Per-Ola,Pàmies, Oscar,Diéguez, Montserrat
, p. 4091 - 4107 (2015)
A new library of modular amino phosphite ligands obtained in a few synthetic steps from enantiopure amino alcohols has been tested in asymmetric Pd-catalyzed allylic substitution. The modular ligand design is crucial to find highly selective catalysts for each substrate type using a wide range of C-, N-, and O-nucleophiles. A DFT study of the species responsible for the enantiocontrol was used to optimize the ligand structure. By selecting the ligand components, we were able to identify unprecedented catalytic systems that can create new chiral C-C, C-N, and C-O bonds in a variety of substrate types (hindered and unhindered) in high yields and enantioselectivities (ee values up to 99 %). Further studies on the Pd-π-allyl intermediates provided a deep understanding of the effect of ligand structure in the origin of enantioselectivity. Potential applications of the new Pd/amino phosphite catalysts were demonstrated by the practical synthesis of a range of chiral carbocycles by simple tandem reactions, with no loss of enantioselectivity.
Formation of azomethine ylids by thermolysis of oxazolidines. Study of the reaction in solution and in the gaseous phase
Bureau, R.,Mortier, J.,Joucla, M.
, p. 584 - 596 (2007/10/02)
Thermolysis of oxazolidines leads to azomethine ylids via cycloreversion.In the liquid phase, these intermediates then give 1-3 dipolar cycloaddition; in the gaseous phase, they lead to aziridines.With an alkyl group in position 2, we observed also the formation of enamines.The effect of substituents on both the cycloreversion reaction and the evolution of azomethine ylids was studied.The mechanism of the process tautomerism aziridine -> azomethine ylid -> enamine is discussed.Keywords - azomethine ylids / oxazolidines / cycloreversion / aziridines / enamines / tautomerism
