Highly regioselective nucleopalladation for the oxidative coupling of internal alkynes with alkenyl alcohols by using green and low-costing oxygen as the sole oxidant was investigated. This one-pot cascade cyclization proceeds through Pd-catalyzed intramolecular C–O bond cyclization, insertion of nonbiased alkenyl alcohols, β-H elimination, and reinsertion of a HPdX species, which is finally transferred
Palladium-Catalyzed 6-<i>endo</i>-Selective Oxycyclization-Alkene Addition Cascades of<i>ortho</i>-Alkynylarylcarboxamides and α,β-Unsaturated Carbonyl Compounds
作者:Youssef Madich、Rosana Álvarez、José M. Aurrecoechea
DOI:10.1002/ejoc.201500797
日期:2015.10
cyclization–coupling cascade reactions between ortho-alkynylarylcarboxamides and methyl vinyl ketone or acrylaldehyde are described. An initial 6-endo-oxypalladation of the triple bond is followed by a C–C coupling to give structurally diverse isochromenimines (and related heterosubstituted derivatives), in which the α,β-unsaturated carbonyl moiety is incorporated as an alkyl-type exocyclic side chain. The coupling