Multicomponent reactions are a valuable tool for the synthesis of functional π-electron systems. Two different approaches can be taken into account for accessing the target structures. In the more conventional scaffold approach an already existing chromophore is coupled with other components to give a complex functional π-system. Here, electronically monotonous components can also be introduced, which may exert synergistic electronic effects within the novel compound. The more demanding chromophore concept generates a complete π-electron system and a scaffold concurrently. The latter approach is particularly stimulating for methodologists since π-systems might be accessible from simple starting materials. This review encompasses the advances in the preparation of functional π-electron systems via multicomponent processes during the past few years, based both on the scaffold and chromophore concepts. Besides the synthetic strategies the most important properties, i.e. redox potentials, absorption and emission maxima or fluorescence quantum yields, of the synthesized molecules are highlighted.

Psoralens are heterocyclic compounds which are, among other uses, used to treat skin deseases in the framework of PUVA therapy. In the dark, they intercalate into DNA and can form photoadducts with thymines upon UV-A excitation, which harms the affected cells. We have recently discovered that after excitation of intercalated psoralens, an efficient photoinduced electron transfer (PET) from DNA occurs. Here, the PET is studied in detail by means of femtosecond transient absorption spectroscopy. Using DNA samples that contain either only GC or AT base pairs, we show that only guanine donates the electrons. Additionally, the substituent effects on PET are studied relying on three different psoralen derivatives. The substitution alters spectroscopic and electrochemical properties of the psoralens, which are determined by cyclic voltammetry and steady state spectroscopy. These experiments allow us to estimate the PET energetics, which are in line with the measured kinetics. Implications for the applications of psoralens are discussed.

This microreview summarizes, explains, and highlights endeavors in the field of multicomponent chemistry with a focus on luminophore development by this approach. Most of the fluorophores accessed by this concept are heterocyclic. The mild reaction conditions of the palladium‐, palladium–copper‐, and copper‐catalyzed processes open highly diversity‐oriented approaches to classical and also unusual luminophore classes in a straightforward and highly convergent fashion.

The cover picture shows that the quest for rapid syntheses of fluorophores, necessary to establish structure–property relationships, can be efficiently and effectively fulfilled by metal‐catalysis‐initiated chromogenic multicomponent reactions, representing a reactivity‐based concept in diversity‐oriented synthesis. Besides solution‐luminescent materials also solid‐state‐emissive chromophores and the young class of aggregation‐induced emission dyes can be readily accessed, enabling one‐pot syntheses of functional ρ‐systems for photonic and electronic materials. Details are presented in the Microreview by L. Levi and T. J. J. Müller on http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201600409/abstract.