Synthesis of 1,4-Dihydropyridines by Regioselective Additions of Benzylic Zinc Bromides to Pyridinium Salts and Their Aromatizations to 4-Benzylpyridines
                                
                                    
                                        作者:A. Paul Krapcho、David J. Waterhouse、Abdelhakim Hammach、Roberto Di Domenico、Ernesto Menta、Ambrogio Oliva、Silvano Spinelli                                    
                                    
                                        DOI:10.1080/00397919708004198
                                    
                                    
                                        日期:1997.3
                                    
                                    Benzylic zinc reagents add with high regioselectivity to 1-(phenoxycarbonyl) salts of methyl nicotinate to yield methyl-1-(phenoxylcarbonyl)-4-benzyl-1,4-dihydronicotinates. The dihydronicotinates on heating with sulfur in decalin afford methyl 4-benzyinicotinates.