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
H. Rudler et al., 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, Organometallics, 17(3), 1998, pp. 361-366
A mixture of 1,2- and 2,5-dihydropyridines and 5-isopropylidene-2,5-di
hydropyridine, obtained from 1-(methoxycarbonyl)-1,2-dihydropyridine a
nd methyllithium followed by protonation, reacts with a series of pent
acarbonyl tungsten(0) alkoxycarbene complexes to afford, besides the e
xpected pyridinium ylide complexes 7, the 2,5-dihydropyridinium ylide
complexes 6 together with the 5-isopropylidene-2,5-dihydropyridinium y
lide complexes 5, which could be separated and fully characterized by
X-ray analysis.