Highly Substituted 2-Amido-furans From Rh(II)-Catalyzed Cyclopropenations of Ynamides
                                
                                    
                                        作者:Hongyan Li、Richard P. Hsung                                    
                                    
                                        DOI:10.1021/ol901860b
                                    
                                    
                                        日期:2009.10.1
                                    
                                    Rh(II)-catalyzed cyclopropenations of ynamides are described. Although an actual amido-cyclopropene intermediate may not be involved, these reactions provide a facile entry to highly substituted 2-amido-turans, thereby formerly constituting a [3 + 2] cycloaddition. An application of these de novo 2-amido-turans in N-tethered intramolecular [4 + 2] cycloadditions is also illustrated, leading to dihydroindoles and tetrahydroquinolines.