Catalytic Photoinduced Intramolecular Decarboxylative and Desulfonylative sp3 Allylation Enabled by Sulfinate Salts.

Herein, we describe a catalytic intramolecular decarboxylative/desulfonylative sp3 allylation triggered by sulfinate salts under light irradiation. The reaction is likely enabled by a non-classical, radical-polar crossover mechanism, allowing rapid and reliable access to valuable allyl architectures from readily accessible precursors. The protocol is characterized by its operational simplicity and scalability, employing abundant, commercially available catalysts.

Trifluoromethylation of Carbonyl and Unactivated Olefin Derivatives by C(sp3 )-C Bond Cleavage.

Herein, we report a Cu-mediated trifluoromethylation of carbonyl-type compounds and unactivated olefins enabled by visible-light irradiation via σ C(sp3 )-C bond-functionalization. The reaction is distinguished by its modularity, mild conditions and wide scope-even in the context of late-stage functionalization-thus offering a complementary approach en route to valuable C(sp3 )-CF3 architectures from easily accessible precursors.

Decarboxylative Conjunctive Cross-coupling of Vinyl Boronic Esters using Metallaphotoredox Catalysis.

The synthesis of complex alkyl boronic esters through conjunctive cross-coupling of vinyl boronic esters with carboxylic acids and aryl iodides is described. The reaction proceeds under mild metallaphotoredox conditions and involves an unprecedented decarboxylative radical addition/cross-coupling cascade of vinyl boronic esters. Excellent functional-group tolerance is displayed, and application of a range of carboxylic acids, including secondary α-amino acids, and aryl iodides provides efficient access to highly functionalized alkyl boronic esters. The decarboxylative conjunctive cross-coupling was also applied to the synthesis of sedum alkaloids.

Site-Selective 1,2-Dicarbofunctionalization of Vinyl Boronates through Dual Catalysis.

A modular, site-selective 1,2-dicarbofunctionalization of vinyl boronates with organic halides through dual catalysis is described. This reaction proceeds under mild conditions and is characterized by excellent chemo- and regioselectivity. It thus represents a complementary new technique for preparing densely functionalized alkyl boron architectures from simple and accessible precursors.

Synthesis of Functionalized Cyclopropanes from Carboxylic Acids by a Radical Addition-Polar Cyclization Cascade.

Herein, we describe the development of a photoredox-catalyzed decarboxylative radical addition-polar cyclization cascade approach to functionalized cyclopropanes. Reductive termination of radical-polar crossover reactions between aliphatic carboxylic acids and electron-deficient alkenes yielded carbanion intermediates that were intercepted in intramolecular alkylations with alkyl chlorides appended to the alkene substrate. The mild conditions, which make use of a readily available organic photocatalyst and visible light, were demonstrated to be amenable to a broad range of structurally complex carboxylic acids and a wide variety of chloroalkyl alkenes, demonstrating exquisite functional group tolerance.

Visible-Light-Mediated Decarboxylative Radical Additions to Vinyl Boronic Esters: Rapid Access to γ-Amino Boronic Esters.

The synthesis of alkyl boronic esters by direct decarboxylative radical addition of carboxylic acids to vinyl boronic esters is described. The reaction proceeds under mild photoredox catalysis and involves an unprecedented single-electron reduction of an α-boryl radical intermediate to the corresponding anion. The reaction is amenable to a diverse range of substrates, including α-amino, α-oxy, and alkyl carboxylic acids, thus providing a novel method to rapidly access boron-containing molecules of potential biological importance.