Diels–Reese reaction

The Diels–Reese reaction is a chemical reaction that involves the conversion of aromatic amines into quinones using sulfur dioxide and oxygen. This reaction is named after the German chemists Otto Diels and Johannes Reese, who first reported it in the early 20th century.

Mechanism

General mechanism of the Diels–Reese reaction.

The Diels–Reese reaction proceeds through a series of steps involving the formation of a sulfonamide intermediate. Initially, the aromatic amine reacts with sulfur dioxide to form a sulfonamide. This intermediate is then oxidized by molecular oxygen to yield the corresponding quinone.

The reaction can be summarized in the following steps:

1. Formation of the sulfonamide intermediate by the reaction of the aromatic amine with sulfur dioxide.
2. Oxidation of the sulfonamide intermediate by oxygen to form the quinone.

Applications

The Diels–Reese reaction is used in the synthesis of various quinones, which are important compounds in organic chemistry and have applications in dyes, pharmaceuticals, and biochemistry. Quinones are also key intermediates in the synthesis of vitamin K and other biologically active molecules.

Limitations

One of the limitations of the Diels–Reese reaction is its requirement for specific conditions, such as the presence of sulfur dioxide and oxygen, which can be challenging to control. Additionally, the reaction is typically limited to aromatic amines, and the yields can vary depending on the substrate and reaction conditions.

Related pages

• Quinone
• Aromatic amine
• Sulfonamide
• Otto Diels
• Johannes Reese