The first iridium-catalyzed intermolecular cyclization between alkynes and ring-fused benzocyclobutenols (RBCB) through C−C bond cleavage is described. A variety of elusive polycyclic aromatic hydrocarbons (PAHs) with multiple substituents are obtained in good yields under mild conditions. This procedure provides a unique and expeditious tool for the synthesis of PAHs.

A conceptually new, efficient, and metal-free approach for the challenging azidocyanation of unactivated alkenes is presented. The strategy of intramolecular distal cyano migration is combined with alkene difunctionalization for the first time. A variety of useful azido-substituted alkyl nitriles are prepared in good yields and, most importantly, with exquisite regio- and stereo-selectivities.

The first iridium-catalyzed intermolecular cyclization between alkynes and ring-fused benzocyclobutenols (RBCB) through C−C bond cleavage is described. A variety of elusive polycyclic aromatic hydrocarbons (PAHs) with multiple substituents are obtained in good yields under mild conditions. This procedure provides a unique and expeditious tool for the synthesis of PAHs.

A conceptually new, efficient, and metal-free approach for the challenging azidocyanation of unactivated alkenes is presented. The strategy of intramolecular distal cyano migration is combined with alkene difunctionalization for the first time. A variety of useful azido-substituted alkyl nitriles are prepared in good yields and, most importantly, with exquisite regio- and stereo-selectivities.

A novel C−C bond-forming strategy employing manganese-catalyzed ring-opening of cyclobutanol substrates, followed by cyanation or ethynylation, is described. A cyano C1 unit and ethynyl C2 unit are regiospecifically introduced to the γ-position of ketones at room temperature, providing a mild yet powerful method for production of elusive aliphatic nitriles and alkynes. All transformations described are based on a common sequence: 1) oxidative ring-opening of cyclobutanol substrates by C−C bond cleavage; 2) radical addition to triple bonds bearing an arylsulfonyl group; and 3) radical-mediated C−S bond cleavage.

A novel C−C bond-forming strategy employing manganese-catalyzed ring-opening of cyclobutanol substrates, followed by cyanation or ethynylation, is described. A cyano C1 unit and ethynyl C2 unit are regiospecifically introduced to the γ-position of ketones at room temperature, providing a mild yet powerful method for production of elusive aliphatic nitriles and alkynes. All transformations described are based on a common sequence: 1) oxidative ring-opening of cyclobutanol substrates by C−C bond cleavage; 2) radical addition to triple bonds bearing an arylsulfonyl group; and 3) radical-mediated C−S bond cleavage.

An oxime-mediated oxychlorination and oxybromination of unactivated olefins relying on palladium catalysis has been developed. A wide range of chlorinated and brominated isoxazolines has been synthesized in moderate to good yields. To demonstrate the value of the method, the brominated isoxazoline has been further converted to other useful synthetic feedstock.

The direct functionalization of an aliphatic C–H bond within a complex molecule through a free-radical pathway is a valuable tool in synthetic chemistry. Herein, we developed an efficient transition-metal-free approach to generate Δ²-isoxazolines from oximes by radical-mediated C(sp³)–H oxidation. Investigation of the mechanism suggested that in the presence of Selectfluor and Bu₄NI, the homolysis of the in situ formed O–I bond generated an iminoxyl radical that facilitated subsequent 1,5-H transfer and C(sp³)–H oxidation.

A novel, manganese-catalyzed oxidative azidation of cyclobutanols is described. A wide range of primary, secondary, and tertiary alkyl azides were generated in synthetically useful yields and exclusive regioselectivity. Aside from linear alkyl azides, otherwise elusive medium-sized cyclic azides were also readily prepared. Preliminary mechanistic studies reveal that the reaction likely proceeds by a radical-mediated CC bond cleavage/CN₃ bond formation pathway.

A novel, manganese-catalyzed oxidative azidation of cyclobutanols is described. A wide range of primary, secondary, and tertiary alkyl azides were generated in synthetically useful yields and exclusive regioselectivity. Aside from linear alkyl azides, otherwise elusive medium-sized cyclic azides were also readily prepared. Preliminary mechanistic studies reveal that the reaction likely proceeds by a radical-mediated CC bond cleavage/CN₃ bond formation pathway.