Pd/Cu-catalyzed cascade Heck-type reactions of alkenyl halides with terminal alkynes toward substituted pyrrolidine analogues

Abstract

A Pd/Cu-Catalyzed cascade Heck-type reactions of alkenyl halides with terminal alkynes has been developed. This research provides an efficient atom-economic approach to access a variety of highly substituted pyrrolidines bearing...

The synthesis of isoxazolines and dihydrooxazines by Pd-catalyzed oxyalkynylation alkenyl oximes with alkynyl bromides

“…Based on above results and previous work, 14,16 a plausible mechanism has been proposed for this Pd(0)/( ii ) catalytic cycle, as shown in Scheme 5. First, oxidative addition of Pd(0)L I on the alkynyl bromide provides Pd( ii ) complex II .…”

“…13 d To the best of our knowledge, these electrophiles in the carboetherification reaction are limited to sp 2 (C) motifs and developing new electrophilic variants would be highly valuable. In continuation of our interests in the study of Pd-catalyzed carboheterofunctionalization of alkene for the construction of heterocycles, 14 we were curious to see if the reaction might be extended to palladium-catalyzed carboetherification of alkenyl oximes with bromoalkyne for the synthesis of alkynyl substituted isoxazolines (Scheme 1c). With this idea in mind, we developed a novel Pd-catalyzed oxyalkynylation of β,γ- or γ,δ-unsaturated oximes with bromoalkyne for the synthesis of isoxazolines and dihydrooxazines bearing an alkyne group by simultaneous formation of C(sp 3 )–O and C(sp 3 )–C(sp) bonds in one step.…”