Palladium Nanoparticles Catalyzed Synthesis of Benzofurans by a Domino Approach

Abstract

Palladium nanoparticles (PdNPs) were used as a catalyst for the one-pot synthesis of a variety of benzofurans by Sonogashira crosscoupling reactions under ambient conditions. The catalyst could be recycled without significant loss in its activity.

Emission pathway switching by solvent polarity: Facile synthesis of benzofuran-bipyridine derivatives and turn-on fluorescence probe for zinc ions

“…Historically, there are multiple synthetic pathways of benzofuran derivatives. [18][19][20][21][22][23][24][25] One of recent major approaches is utilizing a transition metal catalyzed cross-coupling reaction of ortho-halogenated phenol, followed by cyclization, [26][27][28][29][30][31] including inter- [32][33][34][35] and intramolecular [36][37][38][39][40] annulation. Amongst these, cyclization reactions of ortho-substituted phenols mediated by various catalysts including palladium, copper, and zinc have been widely utilized to prepare benzofuran derivatives.…”

A Simple and Efficient Process for the Synthesis of Novel Heterocycles Containing Benzofuran Moiety Using Thiocarbohydrazide as a Precursor

“…Various synthetic methods are reported for the production of benzofurans . The most common and recent synthetic processes for the production of benzofurans involve treatment of ortho ‐hydroxystilbenes with (diacetoxyiodo)benzene in the presence of iodine reagent in acetonitrile at room temperature for 1–3 h , Sonogashira cross‐coupling reaction of 2‐iodophenols and acetylenes in the presence of palladium nanoparticles, triphenylphosphine, and potassium carbonate , reductive cyclization of 1‐(2‐hydroxyphenyl)propargyl alcohols in acetonitrile at room temperature in the presence of palladium acetate, tert ‐butyl isocyanide, and cesium carbonate, reaction of O ‐arylhydroxylamine hydrochlorides and ketones in tetrahydrofuran in the presence of methanesulfonic acid at 60°C for 2–24 h , reaction of ethyl acetohydroximate and arylhalides in dioxane in the presence of excess hydrogen chloride at 70°C , and reaction of salicylaldehydes and excess diazo compounds in dichloroethane in the presence of a rhodium (III) catalyst and silver bis(trifluoromethanesulfonyl)imide . However, these synthetic procedures involve the use of starting materials that might need to be synthesized first, expensive or hazardous catalysts, and/or long reaction time.…”

Synthesis of New 2-Arylbenzo[b]furan Derivatives via Palladium-Catalyzed Suzuki Cross-Coupling Reactions in Aqueous Media

“…2-Arylbenzo[ b ]furan moiety is a common structural subunit found in natural products [ 1 , 2 , 3 ] and synthetic compounds with important biological activities [ 4 , 5 , 6 , 7 ]. For example, a representative complex of the natural 3-deformylated 2-arylbenzo[ b ]furan is ailanthoidol in ( Figure 1 , 1 ), which was isolated from the chloroform-soluble fraction of the tree of Zanthoxylum ailanthoides , was found to have a broad range of biological activities such as anticancer [ 8 ], immunosuppressive [ 9 , 10 , 11 ], antivirus [ 12 , 13 , 14 , 15 ], antioxidant [ 10 , 11 ], antifungal [ 16 ], and antifeedant activities [ 17 ].…”