Pd-Catalyzed cross-coupling synthesis of 4-aryl-3-formylcoumarins

The threefold cross-coupling of triarylbismuth reagents with 4-chloro-3-formylcoumarins furnished the corresponding 4-aryl-3-formylcoumarins in a chemoselective manner with high yields under Pd-catalyzed conditions. This method was successfully applied to electronically different triarylbismuth reagents and 4-chloro-3-formylcoumarins preserving the 3-formyl group in the coumarin scaffold.

Copper-catalyzed synthesis of 1-(2-benzofuryl)-N-heteroarenes from o-hydroxy-gem-(dibromovinyl)benzenes and N-heteroarenes

An efficient method for the synthesis of 1-(2-benzofuryl)-N-heteroarenes is developed from o-hydroxy-gem-(dibromovinyl)benzenes and N-heteroarenes under copper-catalyzed tandem reaction conditions. This methodology displayed a broad substrate scope and high yields in the preparation of a variety of 1-(2-benzofuryl)-N-heteroarenes. Further, 1-(2-benzofuryl)-N-heteroarenes were also applied in the synthesis of polycyclic benzofuro-indolo-pyridine scaffolds under palladium-catalyzed dehydrogenative coupling conditions. Overall, the present tandem approach is general, synthetically advantageous and avoids air-sensitive reagents.

Catalyst-Free Synthesis of Benzofuran Derivatives from Cascade Reactions between Nitroepoxides and Salicylaldehydes

Different benzofuran derivatives are synthesized via a catalyst-free reaction between nitroepoxides and salicylaldehydes. In the employed methodology, K₂CO₃ and DMF have been used at 110 °C, and the reactions were completed after 12 h in 33-84% yields. The highest yields were obtained using 3-nitrosalicylaldehyde. Finally, a plausible mechanism was proposed for the reaction, and some evidence was provided for this mechanism such as the detection of released acetate anion (using FTIR) and isolation and structure determination of the critical intermediate.

Tandem Synthesis of 2-Carboxybenzofurans via Sequential Cu-Catalyzed C-O Coupling and Mo(CO)6-Mediated Carbonylation Reactions

A modular tandem synthesis of 2-carboxybenzofurans from 2-gem-dibromovinylphenols has been established based on a sequence of Cu-catalyzed intramolecular C-O coupling and Mo(CO)₆-mediated intermolecular carbonylation reactions. This protocol allowed one-step access to a broad variety of functionalized benzofuran-2-carboxylic acids, esters, and amides in good to excellent yields under Pd- and CO gas-free conditions.

Cross-coupling reactivity of 1,1-dichloroalkenes under palladium catalysis: domino synthesis of diarylalkynes

An efficient synthesis of diarylalkynes was achieved from the domino cross-coupling reaction of 1,1-dichloroalkenes with triarylbismuth reagents under palladium-catalyzed conditions.

Functional group manoeuvring for tuning stability and reactivity: synthesis of cicerfuran, moracins (D, E, M) and chromene-fused benzofuran-based natural products

The protecting group manoeuvring as a strategy was applied in tuning the stability and reactivity of substituted gem-dibromovinylphenols (12a and 22) for the domino synthesis of benzofuran-based natural products. (1–8).

Substrate-driven selective mono- and bis-couplings of ortho-(OTf/I/Br) substituted gem-dibromovinylarenes

A one-pot approach with the substrate-driven selective and competitive reactivity of ortho-trifloxy, iodo or bromo functionalized gem-dibromovinylarenes was studied under Pd-catalyzed conditions.

Synthesis of Highly Functionalized Triarylbismuthines by Functional Group Manipulation and Use in Palladium- and Copper-Catalyzed Arylation Reactions

Organobismuthines are an attractive class of organometallic reagents that can be accessed from inexpensive and nontoxic bismuth salts. Triarylbismuthines are particularly interesting due to their air and moisture stability and high functional group tolerance. We report herein a detailed study on the preparation of highly functionalized triarylbismuth reagents by triple functional group manipulation and their use in palladium- and copper-catalyzed C-, N-, and O-arylation reactions.

Rapid threefold cross-couplings with sterically bulky triarylbismuths under Pd–Cu dual catalysis

The threefold cross-coupling reactivity of sterically highly demanding bulky triarylbismuths was addressed with task specific Pd–Cu dual catalytic conditions.

Rapid access to unsymmetrical 1,3-diynes and 2,5-disubstituted thiophenes under ligand and Pd/Ni-free Cu-catalysis

A Pd/Ni-free copper-catalysed tandem synthesis was realized for rapid access to unsymmetrical 1,3-diynes from 1,1-dibromoalkenes and terminal alkynes.

A concise route to functionalized benzofurans directly from gem-dibromoalkenes and phenols

A tandem strategy for the construction of benzofuran motifs has been developed directly from gem-dibromoalkenes and phenols under palladium-catalyzed conditions.

Syntheses of indolizinones from an intramolecular one-pot process of gem-dibromoolefins

A rare type of indolizinone is constructed from an Intramolecular one-pot process from gem-dibromoolefins.

Palladium-catalyzed tandem reaction of 2-hydroxyarylacetonitriles with sodium sulfinates: one-pot synthesis of 2-arylbenzofurans

Palladium-catalyzed desulfinative addition and intramolecular annulation tandem reactions of 2-hydroxyarylacetonitriles with sodium sulfinates for one-pot synthesis of 2-arylbenzofurans.