Herein, we report regio- and stereoselective intramolecular direct arylations of N-(2-bromophenyl)-2-furancarboxamides 1 to produce spirooxindoles 2 and 5H-furo[2,3-c]quinolin-4-ones 3 under different reaction conditions. Specifically, in the presence of Pd(PPh) as a catalyst, PPh as a ligand, and KCO as a base, substrates 1 underwent intramolecular α-arylation, possibly via a Heck insertion pathway, to provide 2, with the Z-isomer being favored. When the base was t-BuOLi and R was an aryl group, the reaction favored E-2, possibly via an electrophilic palladation pathway. In contrast, in the presence of PdCl as a catalyst, (o-OMePh)P as a ligand, and PivOH as an additive, substrates 1 underwent intramolecular β-arylation to provide 3, possibly via a concerted metalation-deprotonation process.

A protocol for synthesis of chalcone derivatives with a 2-pyridone subunit from N-(2-furanylmethyl) alkynamides is reported. This synthesis involves Pd/Cu-catalyzed oxidative furan-yne cyclization at room temperature in air and may proceed via nucleopalladation of the alkyne to form a vinylpalladium intermediate, with a furan ring acting as the nucleophile.

A protocol for FeCl2-catalyzed oxidative decarbonylative α-alkylation of acyl furans using alkyl aldehydes as the alkylating agents has been developed. This protocol affords α-alkyl-α-acylfurans in moderate to good yields in a practical and sustainable fashion. Mechanistic studies suggest that the reaction proceeds via generation of an alkyl radical from the alkyl aldehyde, addition of the radical to the furan ring, and subsequent rearomatization.

Main observation and conclusion Polycyclic indolines and indolenines were synthesized via base‐catalyzed intramolecular dearomatizing 3‐alkenylation reactions of alkynyl indoles 1 at room temperature. The base enhanced the nucleophilicity of the carbon at the 3‐position of the indole moiety, facilitating an exclusive 5‐exo‐dig cyclization reaction with the alkyne to form spiroindolenines 2. The imine functionality of 2 could undergo in situ nucleophilic addition to form spiroindolines 3 when R was a carbamoyl group or reduction to form spiroindolines 4 when R was H.

Dearomatization reactions are among the most efficient chemical processes, combining atom economy, stereospecificity and the ability to generate molecular complexity in a single step. Dearomative vinylation reactions provide a synthetic connection between readily available, simple aromatic starting materials and more unsaturated alkynes. The last decade has witnessed a steady increase in the development of transition metal-catalyzed dearomative vinylation methods of electron rich aromatic compounds with alkynes, providing new synthetic approaches to high-value building blocks and natural products. This review aims to serve as a comprehensive reference for work in transition metal-catalyzed dearomative vinylation reactions of electron rich aromatic compounds with alkynes.