Design, Synthesis, and Application of Enantioselective Coupling Reagent with a Traceless Chiral Auxiliary
                                
                                    
                                        作者:Beata Kolesinska、Zbigniew J. Kaminski                                    
                                    
                                        DOI:10.1021/ol802691x
                                    
                                    
                                        日期:2009.2.5
                                    
                                    Stable chiral N-triazinylbrucinium tetrafluoroborate enantioselectively activates racemic carboxylic acids yielding enantiomerically enriched amides, esters, and dipeptides with er from 8:92 to 0.5:99.5. Due to the departure of a chiral auxiliary after the activation of the carboxylic function, all of the subsequent stages of the coupling reaction proceed without any perturbation caused by a chirality discriminator (traceless). Therefore, the advantageous coupling conditions, configuration, and enantiomeric purity of the final product are entirely predictable from the model experiment.