Catalyst‐Free Electrophilic Ring Expansion of <i>N</i>‐Unprotected Aziridines with <i>α</i>‐Oxoketenes to Efficient Access 2‐Alkylidene‐1,3‐Oxazolidines
Xingpeng Chen, Z.-T. Huang, Jiaxi Xu
Abstract
Abstract 2‐(2‐Oxoalkylidene)‐1,3‐oxazolidine derivatives were synthesized in good to excellent yields regiospecifically through the catalyst‐free electrophilic ring expansion of N ‐unprotected aziridines and the ketene C=O double bond of α‐oxoketenes, in situ generated from the microwave‐assisted Wolff rearrangement of 2‐diazo‐1,3‐diketones. The ring expansion predominantly underwent an S N 1 process and the hydrogen bond decides the ( E )‐configuration of products. magnified image
Topics & Concepts
ChemistryElectrophileKeteneRing (chemistry)OxazolidineCatalysisDiazoDouble bondWolff rearrangementMedicinal chemistryHydrogen bondStereochemistryPolymer chemistryOrganic chemistryMoleculeSynthesis and Catalytic ReactionsCyclopropane Reaction MechanismsSynthesis of β-Lactam Compounds