Application of light-promoted Minissci C-H alkylation reaction in preparation of alkyl-substituted azacycle

Abstract

The invention belongs to the technical field of fine chemicals, and particularly relates to a method for preparing alkyl-substituted azacycle through a Minissci CH alkylation reaction which is promoted by light and takes aldehyde or ketone without an oxidizing agent as an alkyl radical source. A nitrogen-containing aromatic ring is mixed with a photocatalyst [Ir (dF (CF3) ppy) 2 (dtbbpy)] PF6, tris (trimethylsilyl) silane (TTMS), trifluoroacetic acid (TFA), aldehyde or ketone and an organic solvent, argon is blown into a reaction bottle, and a reaction is carried out under irradiation of 36W 490nm blue light. A sodium bicarbonate solution is added, liquid is separated, an organic layer is dried, a solvent is removed by spinning, and column chromatography is carried out to obtain a pure product.

Description

technical field

[0001] The invention belongs to the technical field of fine chemicals, and in particular relates to the application of light-promoted Minisci C-H alkylation reaction without an oxidant as the source of alkyl radicals in the preparation of alkyl-substituted nitrogen heterocyclic rings. Background technique

[0002] Nitrogen-containing aromatic rings are widely found in natural products, drug molecules, organic materials and ligands. The late modification of nitrogen-containing aromatic rings by selective carbon-hydrogen bond functionalization is of great significance. The addition reaction of free radicals to nitrogen-containing aromatic rings under acidic and oxidative conditions, namely the Minisci reaction, provides a very efficient method for the synthesis of alkyl-substituted nitrogen-containing aromatic rings. Traditional Minisci reactions often require excess oxidants, acids and high temperatures, which greatly limit the scope of substrate application....

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