Effect of Remote Picolinyl and Picoloyl Substituents on the Stereoselectivity of Chemical Glycosylation
                                
                                    
                                        作者:Jagodige P. Yasomanee、Alexei V. Demchenko                                    
                                    
                                        DOI:10.1021/ja307355n
                                    
                                    
                                        日期:2012.12.12
                                    
                                    O-Picolinyl and O-picoloyl groups at remote positions (C-3, C-4, and C-6) can mediate glycosylation reactions by providing high or even complete facial selectivity for the attack of the glycosyl acceptor. The set of data presented herein offers a strong evidence of the intermolecular H-bond tethering between the glycosyl donor and glycosyl acceptor counterparts while providing a practical new methodology for the synthesis of either 1,2-cis or 1,2-trans linkages. Challenging glycosidic linkages including alpha-gluco, beta-manno, and beta-rhamno have seen obtained with high or complete stereocontrol.