Stereoselective dienylation of propargylic esters with nucleophiles via transition metal catalysis is a powerful method for accessing conjugated dienes. In particular, divergent synthesis beyond 1,3-dienes can be realized.
A Pd(II)-catalyzed highly regioselective dienylation of sp3 C–H bonds has been accomplished engaging allenes for a variety of aliphatic carboxamides including fatty acids and amino acids.
We have developed a palladium-catalyzed propargylic substitution with alcohols as nucleophiles, wherein monohydric alcohols allow the synthesis of 2-alkoxy-1,3-dienes, while the use of diols allows the formation of 1,4-dioxane derivatives.
An efficient red-shift strategy contributing to NIR arylacetylene-containing rhodamines has been first developed via desulfitative Sonogashira cross-coupling of thiopyronin with a broad substrate scope, good yields, and bioimaging potential.
This review analyses recent advances and strategies employed in the Pd-AAA of nucleophilic prochiral heterocycles. Each section is focused on a specific heterocycle, where optimisation data and reaction scope have been carefully analysed.