Pd(0)-complexed 3-aryl or 2,3-diaryl propenylcarbenes generated from α-silyl-, α-germyl-, or α-boryl-σ-allylpalladium intermediates undergo self-dimerization to provide 1,6-di- or 1,2,5,6-tetraarylhexa-1,3,5-trienes in good to high yields. This method allows the use of a π-allylpalladium intermediate for a carbenoid precursor. Furthermore, the obtained 1,2,5,6-tetraarylhexa-1,3,5-trienes exhibit aggregation-induced emission enhancement property.

Practical and Convenient Synthesis of 1,6-Di-or 1,2,5,6-Tetra-arylhexa-1,3,5-trienes by the Dimerization of Pd(0)-Complexed Alkenylcarbenes Generated from -Allylpalladium Intermediates. -Application of the 4-methoxyphenyl-substituted substrate analogue of (I) yields an instable mixtures of isomers. Conversion of the 2-pyridyl-substituted substrate does not give the desired product. The X-ray structure of (VIIa) and the fluorescence properties of (VIIa-c) are investigated. -(HORINO*, Y.; TAKAHASHI, Y.; KOKETSU, K.; ABE, H.; TSUGE, K.; Org. Lett. 16 (2014) 12, 3184-3187, http://dx.

p‐Benzochinon (I) reagiert mit Alkoholen (II) beim Durchlaufen einer Schicht von mit Salzsäure aktiviertem Aluminiumoxid zu Alkoxybenzochinonen (III), 2,5‐Dialkoxybenzochinonen (IV) und Hydrochinon (V).