Heterobifunctional azobenzenes and stilbenes were rationally synthesized from available precursors via Mills/Horner–Wadsworth–Emmons reactions and subsequent modification or selective functionalization of symmetric starting materials. These compounds were used in a series of model one-pot reactions to show their application for facile bridging of different molecular building blocks with a photosensitive linker.

Abstract

Azobenzenes are versatile molecules that have first been discovered as dyes and since found its way to various areas of modern life, ranging from food and textiles industry to the cutting-edge research in chemistry and medicine. Stilbenes, sharing the similar structure and isomerization behavior, are important moieties in medicinal and material chemistry. Since molecules of both classes are usually designed ad hoc for a specific purpose, studies related to syntheses of ready-to-go azobenzene and stilbene building blocks are scarce. In this article, we present a series of novel heterobifunctional cores possessing pairs of functional groups enabling stepwise or one-pot construction of molecules of interest using thoroughly studied methodologies of the CuAAC click chemistry, cross-coupling, and alkylation. Developed synthetic strategies, being simple and tolerable to a wide range of functionalities, can be applied to azobenzenes and stilbenes having auxiliary substituents and different substitution patterns.