Synthesis of silicon-containing macrocyclic compounds by using intramolecular [2+2] photocycloaddition reactions of bis-dimethylsilyl-linked styrenes and stilbenes

摘要

A method for the synthesis of silicon-containing macrocyclic compounds, using intramolecular [2?+?2] photocycloaddition reactions of bis-dimethylsilyl-linked styrene or stilbene derivatives, is described. Photoirradiation of benzene solutions ofo- andm-bis(dimethylsilylmethyl)benzene derivatives, containing two styrene units, promotes efficient formation of intramolecular [2?+?2] photocycloadducts. In contrast, photoreaction of the correspondingpara-substituted analog generates only dimers. Photoreactions of bis(dimethylsilylmethyl)benzene derivatives, possessing two stilbene units produce intramolecular [2?+?2] photocycloadducts along with products ofcis-transphotoisomerization. The efficiencies of these intramolecular photoreactions depend on the distances between two double bonds undergoing [2?+?2] cycloaddition. Triplet-sensitized photoreactions of the stilbene derivatives lead tocis-transisomerization exclusively. Finally, photoreactions of the stilbene derivatives in the presence of molecular oxygen produce phenanthrene derivatives as side products.