Visible-Light-Driven Photocatalyst-Free Deoxygenative Radical Transformation of Alcohols to Oxime Ethers.

A visible-light-driven deoxygenative cross-coupling of alcohols with sulfonyl oxime ethers has been developed by using xanthate salts as alcohol-activating groups. Upon convenient generation and direct photoexcitation of xanthate anions, a broad range of alcohols including primary ones can efficiently undergo this transformation to afford diverse oxime ethers and derivatives. This one-pot protocol features mild conditions, broad substrate scope, and late-stage applicability, without the need for any external photocatalysts or electron donor-acceptor complex formation.

Metal-Free C(sp3)-H Azidation in a Radical Strategy for the Synthesis of 3-Azido-2-oxindoles at Room Temperature.

A novel and environmentally attractive C(sp3)-H azidation of 2-oxindoles involving the formation of a C-N bond was developed. This methodology achieved for the first time 3-azido-2-oxindole construction under metal-free conditions at room temperature via a radical strategy. PhI(OAc)2 was used as the oxidant and Et3N was used as the additive in this transformation. Furthermore, the mechanistic study indicated that this azidation involved a radical process.