Selective reduction of alkynes by the reagent Sml2 - Transition metal catalysts - proton donors
摘要:
Alkynes were selectively reduced to cis-olefins under mild conditions by Sml2 in admixture with first-row transition metal catalysts and appropriate proton donors, in which the corresponding transition metal hydrides are presumed as the reactive species. The conditions also effected the conversion of 1,6-diynes to the corresponding five-membered carbocycles.
Alkynes were selectively reduced to cis-olefins under mild conditions by Sml2 in admixture with first-row transition metal catalysts and appropriate proton donors, in which the corresponding transition metal hydrides are presumed as the reactive species. The conditions also effected the conversion of 1,6-diynes to the corresponding five-membered carbocycles.
AuBr<sub>3</sub>- and Cu(OTf)<sub>2</sub>-Catalyzed Intramolecular [4 + 2] Cycloaddition of Tethered Alkynyl and Alkenyl Enynones and Enynals: A New Synthetic Method for Functionalized Polycyclic Hydrocarbons
Cu(OTf)2 catalyst, the corresponding dihydronaphthyl ketone products 13 and 15 were obtained in high yields, respectively. The present formal [4 + 2] intramolecular cycloaddition proceeds most probably through the coordination of the triple bond at the ortho position of substrates to Lewis acids, the formation of benzopyrylium ate complex 16 via the nucleophilic addition of the carbonyl oxygen atom, the