Benzofurans from Benzophenones and Dimethylacetamide: Copper‐Promoted Cascade Formation of Furan O1C2 and C2C3 Bonds Under Oxidative Conditions

Abstract

For the title synthesis, commercially available or readily synthesized starting materials are used.

Contribution to the Chemistry of (ClC{PPh3}2)Cl, a Precursor of the Carbodiphosphorane C(PPh3)2

“…In this context, we became interested in the prospect of synthesizing 2,3‐disubstituted benzofuran derivatives starting from phenols. Although numerous approaches have been made to synthesize these scaffolds,9 the widely adopted method is the transition metal‐catalyzed annulation10 by using pre‐functionalized phenol,6a,11 thus limiting the scope of the reaction to a considerable extent. Free phenols also have been employed in several cases but reactions with cinnamic acids remained exceedingly rare 12…”

Iron‐Catalyzed Direct Synthesis of Densely Substituted Benzofurans and Naphthopyrans from Phenolic Compounds and Propargylic Alcohols

“…While benzofurans were formed in many of these cases, Li3f showed that the pyran derivatives could be generated in high selectivity in the presence of FeCl 3 catalyst. In addition, the copper‐promoted synthesis of benzofurans using ortho ‐hydroxybenzophenones or ortho ‐hydroxy‐α‐arylstyrenes has also been reported 5. However, these protocols were multistep syntheses and required frequently the use of noble metals such as Pd, Pt, Au, In, and Ru as catalysts.…”

Palladium‐Catalyzed Synthesis of 2,3‐Disubstituted Benzofurans: An Approach Towards the Synthesis of Deuterium Labeled Compounds

“…[ 5 ] Therefore, synthesis of these organic motifs has drawn significant attention from the synthetic community. [ 6 ] Recently, we have contributed to this area by synthesizing a wide array of 2-substituted benzofurans through a unique Pd-catalyzed annulation of simple phenols and olefins. [ 7 ] Of more interest was an orthogonal approach with cinnamic acids, which gave rise to 3-substituted benzofurans with excellent selectivity.…”

“…[ 8 ] In this context, we became interested in the prospect of synthesizing 2,3-disubstituted benzofuran derivatives starting from phenols. Although numerous approaches have been made to synthesize these scaffolds,[ 9 ] the widely adopted method is the transition metal-catalyzed annulation[ 10 ] by using pre-functionalized phenol,[ 6a ],[ 11 ] thus limiting the scope of the reaction to a considerable extent. Free phenols also have been employed in several cases but reactions with cinnamic acids remained exceedingly rare.…”