RESUMO
Herein, we report a general method for copper-catalyzed N-arylation of isatoic anhydrides with unsymmetrical iodonium salts at room temperature. The developed catalytic protocol is mild and operationally simple, and aryl(TMP)iodonium trifluoroacetate is employed as the arylating partner. The methodology offers the broad applicability of both structurally and electronically diverse aryl groups from aryl(TMP)iodonium salts to access N-arylated isatoic anhydrides in moderate to excellent yields (53-92%). Moreover, the substituted isatoic anhydrides are equally compatible with the protocol too. To demonstrate the synthetic utilities of the N-arylation process, we also report an alternative approach for biologically relevant fenamic acid derivatives and N,N'-diarylindazol-3-ones in a one-pot step economical system. In addition, the scale-up synthesis of flufenamic acid is also illustrated.
RESUMO
Oxidative cleavage of styrene CâC double bond is accomplished by employing a nitrogen-rich triazine-based microporous organic polymer as an organocatalyst. We report this regioselective reaction as first of its kind with no metal add-ons to afford benzaldehydes up to 92% selectivity via an unusual Wacker-type CâC bond cleavage. Such a reaction pathway is generally observed in the presence of a metal catalyst. This polymer further shows high catalytic efficiency in an anaerobic oxidation reaction of benzyl alcohols into benzaldehydes. The reaction is mediated by a base via the in situ generation of hydride ions. This study is supported by experiments and computational analyses for a free-radical transformation reaction of oxidative CâC bond cleavage of styrenes and a hydride elimination mechanism for the anaerobic oxidation reaction. Essentially, the study unveils protruding applications of metal-free nitrogen-rich porous polymers in organic transformation reactions.