Reactions of guaiazulene with methyl terephthalaldehydate and 2-hydroxy- and 4-hydroxybenzaldehydes in methanol in the presence of hexafluorophosphoric acid: comparative studies on molecular structures and spectroscopic, chemical and electrochemical prop

Reaction of guaiazulene () with methyl terephthalaldehydate () in methanol in the presence of hexafluorophosphoric acid at 25 °C for 2 h under aerobic conditions gives (3-guaiazulenyl)[4-(methoxycarbonyl)phenyl]methylium hexafluorophosphate () in 94% yield. Similarly, reactions of with 2-hydroxybenzaldehyde () and 4-hydroxybenzaldehyde () under the same reaction conditions as give (3-guaiazulenyl)(2-hydroxyphenyl)methylium hexafluorophosphate () and (3-guaiazulenyl)(4-hydroxyphenyl)methylium hexafluorophosphate () in 89 and 97% yields, respectively. Comparative studies on the molecular structures as well as the spectroscopic, chemical and electrochemical properties of the monocarbocation compounds stabilized by 3-guaiazulenyl and 4-(methoxycarbonyl)phenyl (or 2-hydroxy- or 4-hydroxyphenyl) groups are reported.