The photochemical behavior of several dienones was studied under aerobic conditions. 2-Allylidene-1,3-cycloalkanediones prepared via Knoevenagel-type condensation between simple readily available 1,3-dicarbonyl substrates and α,β-unsaturated aldehydes afforded 1,2,4-trioxane derivatives upon UVA irradiation in the presence of oxygen. This domino self-sensitized photooxygenation cascade of conjugated carbonyl systems proceeds stereoselectively and involves the formation of two new oxa-cycles, three new bonds (two C–O), and three stereocenters.

Aim: Encouraged by the antitumor activity exhibited by triazolylpeptidyl penicillins, we decided to synthesize and evaluate a library of peptoid analogs. Results: The replacement of the dipeptide unit of the reference compound, TAP7f, was investigated. In addition, the effect of the triazole linking group on the biological activity of these new derivatives was evaluated, exchanging it with a glycine spacer. The cytotoxic effect of the library compounds was determined in the B16-F0 cell line and compared with the effects on normal murine mammary gland cells. Conclusion: Among the tested compounds, peptoid 4e exhibited the highest antiproliferative activity.

Transition metal‐catalyzed, C−C and C−N bond‐forming reactions have made an enormous impact in the way complex molecules are assembled. The benefits of solid‐phase chemistry soon made this type of reaction applicable to solid‐supported processes. In this review, we report the most recent applications and possibilities of this combination. Remarkably, the solid‐phase CuAAC and ring‐closing metathesis have demonstrated an important role in synthetic biology, alike more traditional Pd‐catalyzed reactions, such as Suzuki‐Miyaura, Heck, Sonogashira, which are valuable tools for accessing libraries of biologically relevant small molecules. Examples proved the validity of solid‐phase transition metal‐catalyzed reactions as a practical and fast strategy to cover the current organic chemistry demands.