Phosphine-Catalyzed Asymmetric Synthesis of α-Quaternary Amine via Umpolung γ-Addition of Ketimines to Allenoates
                                
                                    
                                        作者:Peng Chen、Junliang Zhang                                    
                                    
                                        DOI:10.1021/acs.orglett.7b03262
                                    
                                    
                                        日期:2017.12.15
                                    
                                    A first phosphine-catalyzed enantioselective umpolung gamma-addition of ketimines to allenoates has been developed that provides efficient access to optically active gamma,delta-unsaturated alpha-amino esters and delta-amino esters with a chiral tertiary stereocenter under mild conditions. The salient features of this reaction include general substrate scope, mild conditions, good yields, high enantioselectivity, ease of scale-up to gram scale, and further transformations.