名称:
Formation and Selective Trapping of 2,5-Dihydropyridine and Its Isopropylidene Derivative by Tungsten(0) Alkylidene Complexes. X-ray Structure of the 5-Isopropylidene-2,5-dihydropyridine Adduct
摘要:
A mixture of 1,2- and 2,5-dihydropyridines and 5-isopropylidene-2,5-dihydropyridine, obtained from 1-(methoxycarbonyl)-1,2-dihydropyridine and methyllithium followed by protonation, reacts with a series of pentacarbonyl tungsten(0) alkoxycarbene complexes to afford, besides the expected pyridinium ylide complexes 7, the 2,5-dihydropyridinium ylide complexes 6 together with the 5-isopropylidene-2,5-dihydropyridinium ylide complexes 5, which could be separated and fully characterized by X-ray analysis.