“Cetyl radicals are very important species in synthetic chemistry. They are often used in the synthesis of complex natural products. However, catalytic chemical transformations using cetyl radicals remain challenging. Their formation often requires” tough “high temperature reaction conditions. “They are non-selective in their reaction paths, which means they are difficult to control,” explains Huan-Ming Huang. The team used cetyl radicals and palladium catalysis stimulated by visible light to generate an MCR between multiple conjugates. In selecting the coupling partners (aldehydes, 1,3-dienes and various nucleophiles), the researchers took into account several aspects: Which substances are necessary for the reaction to take place, which ones are readily available and which products are useful? “We have been able to tame cetyl-type roots by combining visible light with small amounts of a commercially available palladium catalyst,” says co-author Peter Bellotti. “This operationally simple, oxidation-neutral and therefore environmentally friendly approach could become a general platform for the construction of so-called composite homoalyl alcohol patterns, a structural pattern often used in synthetic chemistry. The one-step synthesis further conversion into valuable products is a testament to the flexibility of this approach “. In addition to the synthetic capabilities of this method, the team investigated the mechanistic complexities using combined experimental mechanistic analysis and functional density theory (DFT) calculations. “We expect that the combination of visible light with transition metals such as palladium could inspire further unpredictable synthetic transformations beyond the established catalytic reactions,” concludes Frank Glorius.
