Recent Trends in the Synthesis and Bioactivity of Coumarin, Coumarin-Chalcone, and Coumarin-Triazole Molecular Hybrids

Molecular hybridization represents a new approach in drug discovery in which specific chromophores are strategically combined to create novel drugs with enhanced therapeutic effects. This innovative strategy leverages the strengths of individual chromophores to address complex biological challenges, synergize beneficial properties, optimize pharmacokinetics, and overcome limitations associated with single-agent therapies. Coumarins are documented to possess several bioactivities and have therefore been targeted for combination with other active moieties to create molecular hybrids. This review summarizes recent (2013-2023) trends in the synthesis of coumarins, as well as coumarin-chalcone and coumarin-triazole molecular hybrids. To cover the wide aspects of this area, we have included differently substituted coumarins, chalcones, 1,2,3- and 1,2,4-triazoles in this review and considered the point of fusion/attachment with coumarin to show the diversity of these hybrids. The reported syntheses mainly relied on well-established chemistry without the need for strict reaction conditions and usually produced high yields. Additionally, we discussed the bioactivities of the reported compounds, including antioxidative, antimicrobial, anticancer, antidiabetic, and anti-cholinesterase activities and commented on their IC50 where possible. Promising bioactivity results have been obtained so far. It is noted that mechanistic studies are infrequently found in the published work, which was also mentioned in this review to give the reader a better understanding. This review aims to provide valuable information to enable further developments in this field.

Phosphine-substituted 1,2,3-triazoles as P,C- and P,N-ligands for photoluminescent coinage metal complexes

A series of homo- and hetero-polynuclear coinage metal complexes based on a phosphine-substituted 1,2,3-triazole system was synthesized.

Green click synthesis of β-hydroxy-1,2,3-triazoles in water in the presence of a Cu(ii)–azide catalyst: a new function for Cu(ii)–azide complexes

A new method for preparing 1,2,3-triazols via a [3+2]-cycloaddition reaction is introduced. The effect of reaction temperature on the epoxide ring opening reactions is also investigated.

2-(1,2,3-Triazol-4-yl)-imidazoline, -oxazoline, -thiazoline and -tetrahydropyrimidine as ligands in copper(II) and nickel(II) complexes

2-(1-Benzyl-1H-1,2,3-triazol-4-yl)-imidazolines (L1 and L2/L2′), -1,3-oxazoline (L3), -1,3-thiazoline (L4) and -tetrahydropyrimidine (L5) were prepared in one step from a 1,2,3-triazole-4-carboxamidinium tetraphenylborate and studied as novel ligands for copper(II) and nickel(II) ions. The solid-state structures of the following complexes were established: [Cu(L1)2](OTf)2, [CuL2L2′(OTf)2] · 2H2O, [[Cu(L4)2(H2O)2](OTf)2 · [Cu(L4)2(OTf)2], [Cu(L5)2(OTf)2], Cu(L3)2Cl2] · THF, [Ni(L1)2Cl2].

Singular supramolecular self-assembling of bis-cyclodextrinyl-bis-lariat hosts with metal bis-aryl-sulfonates as guests

Interlocked [2]rotaxanes were built from bis-cyclodextrinyl-bis lariats (CD-Ls) and bis-aryl sulfonates by a spontaneous dual cation/anion self-assembling process. Original CD-L's have been synthesized in high yield by a one step “click” or Staudinger–Aza-Wittig (SAW) coupling reaction.

C-Functionalized chiral dioxocyclam and cyclam derivatives with 1,2,3-triazole units: synthesis, complexation properties and crystal structures of copper(ii) complexes

NewC-functionalized dioxocyclam and cyclam derivatives with 1,2,3-triazoles attached to carbon atoms within the skeleton were designed as valuable bifunctional chelators for molecular imaging.