Remote C(sp)-H Carboxylation with CO via Visible-Light-Catalyzed 1,5-Hydrogen Atom Transfer.

The direct carboxylation of C(sp)-H bonds with CO represents a challenging but highly attractive strategy in organic synthesis. In this study, we presented a visible-light-catalyzed strategy for carboxylating remote C(sp)-H bonds with CO via aryl radical induced 1,5-hydrogen atom transfer. This transformation involves generating alkyl radicals via 1,5-hydrogen atom transfer from aryl radicals, forming alkyl carbanions as key intermediates, and a subsequent nucleophilic attack with CO, thereby enabling access to a variety of tertiary and quaternary carboxylic acids in moderate to good yields.

CO-promoted photocatalytic aryl migration from nitrogen to carbon for switchable transformation of N-arylpropiolamides.

Photocatalytic N-to-C aryl migration allows for quick construction of highly useful amide derivatives from readily available compounds. By developing the reactions of sodium sulfinates with the N-aryl-propiolamides, we herein demonstrate that the CO-promoted visible-light-induced method enables a large variety of aryl groups on nitrogen atoms of the N-arylamides to undergo efficient aryl migration from N atom to C atom to synthesize tetra- and tri-substituted alkenyl amides selectively. 1,4-N-to-C aryl migration is a key step in this transformation which is achieved through photocatalytic radical-polar crossover pathway.

Substituent-Determined Intramolecular Hydrogen Transfer for Photopromoted Intermolecular Cycloaddition of Anthraquinones with Aryl Olefins.

The formation of intramolecular hydrogen bonds in anthraquinones makes them inert to photoinduced reactions; therefore, it is a great challenge to phototransform these compounds. Herein, we reported a formal visible-light-induced [4 + 2] cycloaddition of both 1-hydroxyanthraquinones and 1-aminoanthraquinones with olefins under external photocatalyst-free conditions with high regioselectivity. More than 60 substrates are disclosed, demonstrating the reliability of this protocol to construct diverse functionalized anthraquinone derivatives.

Oxidation of Enones for Regioselective [3+2] Cycloaddition through γ-Enone Radical Intermediates.

Invited for the cover of this issue is the group of Min Zhang and Weiping Su at the Fujian Institute of Research on the Structure of Matter. Read the full text of the article at 10.1002/chem.

Oxidation of Enones for Regioselective [3+2] Cycloaddition through γ-Enone Radical Intermediates.

Herein, an oxidization reaction of enones with a Cu complex that leads to a new type of regioselective [3+2] cycloaddition is reported. Highly functionalized cyclopentenes and spirocyclic compounds are obtained in moderate-to-good yields. This cycloaddition reaction occurred through the formation of γ-enone radicals, providing a rarely explored reactivity pattern for enones.