Diastereoselective cycloaddition of ( S )- N -(1-phenylethylimino)trifluoropropionate and trifluoroethylphosphonate with diazomethane
                                
                                    
                                        作者:Yuliya V. Rassukana、Ludmyla V. Bezgubenko、Oleg V. Stanko、Eduard B. Rusanov、Irina B. Kulik、Petro P. Onys'ko                                    
                                    
                                        DOI:10.1016/j.tetasy.2017.03.009
                                    
                                    
                                        日期:2017.4
                                    
                                    The cycloaddition reaction of (S)-(alpha-phenylethylimino)trifluoropropionate with diazomethane leads to a diastereomeric mixture (4.5:1) of 5-trifluoromethyl-1,2,3-triazoline-5-carboxylates. Enantiopure diastereomers were isolated by column chromatography and converted into their respective non-racemic 2-trifluoromethyl-aziridine-2-carboxylates and carboxylic acids. The absolute configuration of newly formed stereogenic centers was determined by XRD analysis. The stereoselective reaction between (S)N-(alpha-phenylethyl)trifluoroacetimidoylphosphonate and diazomethane produces a diastereomeric mixture (2.5:1) of 5-trifluoromethyltriazoline-5-phosphonates readily separated by column chromatography in diastereomerically pure forms. (C) 2017 Elsevier Ltd. All rights reserved.