3-Amino-1,2,4-triazolium salts as NHC-proligands: synthesis and postmodification of a new type of amino-functionalized Pd/NHC complexes

Bioactivities of Triazolium‐Based N‐Heterocyclic Carbene Salts

“…1,2,4‐Triazolium salt derivatives have been extensively studied as N ‐heterocyclic carbene (NHC) catalysts [1] and ligands [2] . Meanwhile, 1,2,4‐triazolium salts have also been reported to possess a wide range of significant bioactivities, such as antibacterial, [3] antifungal, [4] anticancer, [5] antiprotozoal, [6] and even worm growth regulation [7] activities.…”

“…1,2,4-Triazolium salt derivatives have been extensively studied as N-heterocyclic carbene (NHC) catalysts [1] and ligands. [2] Meanwhile, 1,2,4-triazolium salts have also been reported to possess a wide range of significant bioactivities, such as antibacterial, [3] antifungal, [4] anticancer, [5] antiprotozoal, [6] and even worm growth regulation [7] activities. It is well known that triazoles are widely used in the development of agrochemicals and medicines based on their highly efficient and broad-spectrum biological activities.…”

Base‐Ionizable Anionic NHC Ligands in Pd‐catalyzed Reactions of Aryl Chlorides

“…The rationale behind this requirement is multifold: such ligands not only stabilize active metal species but also provide noncovalent stabilizing interactions during oxidative addition stages, making the oxidative addition step more energetically feasible [16] . Although various Nitron‐type triazoles containing N‐aryl groups, such as Ph, 4‐bromophenyl, 1‐naphtyl‐ and unbulky alkylated aryl groups, as well as with N‐alkyl substituents, have been reported in the literature [9d,12e,h,i,17] . However, as of now, Nitron‐type ligands containing bulky N‐aryl groups, for instance, Mes or DiPP, have remained largely elusive in literature.…”

“…Among these ligands, Nitron (R = R′ = R′′ = Ph), a well‐known analytic reagent for gravimetric determination of nitrate ions, [13] has attracted attention as an NHC proligand more than 10 years ago [12a] . Complexes of Pd, [12g–k] Rh, [12a,e,g] Ru, [12b,g] Ir, [12g,j] Ni, [9d,12j] and coinage metals (Cu, Ag and Au) [12c,e] with Nitron and its analogs have been reported in the literature, some of which have been studied as catalysts. For example, complexes of Ir with Nitron catalyzed dehydrogenation of formic acid, aldehyde hydrosilylation, dehydrocoupling of hydrosilanes and alcohols, and ketone reduction via transfer hydrogenation [12j] .…”