Brönsted Acid-Mediated Intramolecular Cyclization of Biaryl Triazenes for the Synthesis of Fluorenes and 9,10-Dihydro-Phenanthrenes
摘要:
The efficient synthesis of fluorenes from biaryl triazenes is successfully developed Up to 27 examples of biaryl triazenes are converted into their corresponding fluorene derivatives in the presence of CF3COOH (4.0 equiv). Mechanism research indicates that the reaction undergoes concerted processes, and pentacoordinate carbocations may be involved in these reactions.
A palladium-catalyzed cross-coupling reaction of aryl halides with 2-chlorobenzoic acids has been developed. The reaction forms C(sp3), C(sp2)-palladacycles through C(sp3)–H activation. The palladacycles react with 2-chlorobenzoic acids through two successive C–C cross-couplings, and two C–C bonds are formed with high chemoselectivity. The reaction provides an innovative method for the synthesis of
The efficient synthesis of fluorenes from biaryl triazenes is successfully developed Up to 27 examples of biaryl triazenes are converted into their corresponding fluorene derivatives in the presence of CF3COOH (4.0 equiv). Mechanism research indicates that the reaction undergoes concerted processes, and pentacoordinate carbocations may be involved in these reactions.