Simple Synthesis of 5-Substituted Resorcinols: A Revisited Family of Interesting Bioactive Molecules

(4-Methoxy-benzylidene)-(3-methoxy-phenyl)-amine, a nitrogen analog of stilbene as a potent inhibitor of melanin production

The current study was carried out to investigate in vitro the effects of (4-methoxy-benzylidene)-(3-methoxyphenyl)-amine on melanin biosynthesis which is closely related to hyper-pigmentation. (4-Methoxy-benzylidene)-(3-methoxy-phenyl)-amine, a nitrogen analog of stilbene, was synthesized by a single step process. This compound inhibited the tyrosinase activity, which converts dopa to dopachrome in the biosynthetic process of melanin, and showed a UV-blocking effect at UV-B band. The compound also exhibited SOD-like activity, which is involved in the protection against auto-oxidation and inhibited melanin production in melan-a cell line. Our results suggest the possibility that (4-methoxy-benzylidene)-(3-methoxy-phenyl)-amine might be used as a skin whitening agent.

Benzylic manganese halides, sulfonates, and phosphates: preparation, coupling reactions, and applications in organic synthesis

The use of highly active manganese, prepared by the Rieke method, for the direct preparation of benzylic manganese reagents was investigated. The oxidative addition of the highly active manganese (Mn) to benzylic halides was easily completed under mild conditions. More importantly, benzylic manganese sulfonates and phosphates were prepared by direct oxidative addition of Mn to the carbon-oxygen bonds of benzylic sulfonates and phosphates. The resulting benzylic manganese reagents were found to undergo cross-coupling reactions with a variety of electrophiles. The majority of these reactions were carried out in the absence of any transition metal catalyst under mild conditions. This approach also provided a facile synthetic route to the preparation of resorcinolic lipids.