Recent advances of Pd-π-allyl zwitterions in cycloaddition reactions

Palladium-catalyzed [6 + 4] cycloaddition with π-allyl all-carbon 1,6-dipole for the synthesis of ten-membered heterocycles

“…2 Among various synthesis strategies, palladium-catalyzed π-allyl dipolar cycloaddition reaction is one of the most direct and effective methods, due to excellent atom economy, high reactivity, exclusive regioselectivity, and good functional group compatibility. 3 Pd-π-allyl dipoles can be divided into heteroatom dipoles and all-carbon dipoles. And the all-carbon dipoles can be further classified into trimethylenemethane (TMM), 4 a vinylcycloprops 4 b and cyclic vinylcarbonates.…”

Construction of 3,4-Dihydroquinolone Derivatives through Pd-Catalyzed [4+2] Cycloaddition of Vinyl Benzoxazinanones with α-Alkylidene Succinimides

“…On the contrary, following the pioneering research of Tunge et al., vinyl benzoxazinones have been recognized as a versatile class of building blocks for the generation of nitrogen-containing heterocycles and widely employed in the development of organic synthetic methodologies. They can readily transform into a zwitterionic Pd-π-allyl complex via oxidative addition/decarboxylation processes in the presence of palladium(0) catalysts . This class of intermediates can act as a transient 1,4-dipole and be efficiently trapped by a variety of dipolarophiles, allowing the formal [4+ n ] cycloadditions to assemble various biologically significant pharmacophore architectures .…”

Asymmetric cascades of the π-allyl complex: a journey from transition-metal catalysis to metallaphotocatalysis

“…, they are transition metal specific. 20 Furthermore, reviews showing enantioselective cascades involving π-allyl intermediates are scarcer. Thus, an accrual of literature showing the new achievements from non-classical synthons would engage younger researchers and could serve as an excellent source of information.…”

“…Despite these substantial accomplishments, reviews elaborating these findings are unfortunately limited to only allyl acetates and in some cases, they have focused on the reaction conditions, i.e., they are transition metal specific. 20 Furthermore, reviews showing enantioselective cascades involving p-allyl intermediates are scarcer. Thus, an accrual of literature showing the new achievements from non-classical synthons would engage younger researchers and could serve as an excellent source of information.…”