1,4-to 1,5-Homologation of Alkene-Carbene and Alkyne-Carbene Complexes of Chromium and Tungsten:The Clue to Reactivity

摘要

The carbene carbon of l,4-alkene and-alkyne carbene complexes of chromium and tungsten(1 and 2)reacts with nucleophiles such as hydrides originating from dihydropyridine and methyllithium to give upon CO and alkyne(or alkene)insertions polycyclic lac-tones 6 and 7,cyclopentanones 10 and 11,and cyclo-pentanols 12.