Multi-aryl substituted olefins and 1,3-dienes are important structural motifs in material molecules, and the stereochemistry of these structures exerts significant influence on the material properties. At present, the lack of effective methods to control the geometry of the double bonds has been a hurdle for the discovery of advanced material. We report herein the development of a 1,4-palladium migration/Suzuki coupling sequence for the efficient synthesis of these interesting molecules. A precise reactivity balance of the used organoboronates played a vital role in this process. The practicality of this method was demonstrated by the excellent capability and flexibility in stereochemical control, broad substrate scope, excellent functional group tolerance, as well as versatile conversion with obtained products and easy scalability. Furthermore, the power of this method is also highlighted by the aggregation-induced emission (AIE) feature studies of some obtained products, especially the easy accessibility of several geometric isomer pairs with a marked difference on photolumnescent quantum yield values.
Stereospecific Synthesis of Multi-Aryl Substituted Olefins and 1,3-Dienes via 1,4-Palladium Migration/Suzuki Coupling Sequence
12 December 2019, Version 1