Iron powder and tin/tin chloride as new reducing agents of Meerwein arylation reaction with unexpected recycling to anilines

Abstract

Simple and rapid route for Meerwein arylation reaction using iron powder or a mixture of tin/tin chloride has been developed. In the presence of iron powder, different aryl diazonium salts reacted with methyl vinyl ketone, acrylates, and isopropenyl acetate. Production of oximes was detected as the main product with acrylates or in a mixture with β-aryl methyl ketones in the case of methyl vinyl ketone. The in situ produced HNO₂ from an excess of NaNO₂/HCl was trapped by alkyl aryl radical to form oximes in the E configuration form. The presence of tin/tin chloride mixture in the reaction of the aryl diazonium salts with methyl vinyl ketone produced Michael products along with β-aryl methyl ketones. The predicted α-aryl methyl ketones from the reaction of isopropenyl acetate with the diazotized anilines were obtained using iron or tin/tin chloride mixture.

GRAPHICAL ABSTRACT

Keywords:

• Diazonium salt
• iron powder
• Meerwein arylation
• radical reaction
• reducing agent
• tin
• tin chloride

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the French and Egyptian governments through a co-financed fellowship granted by the French Embassy in Egypt (Institut Français d’Egypte) and the Science and Technology Development Fund (STDF). Additionally, Plant Advanced Technologies (PAT) is a private company of research. It financed the project of post-doc of A.B Abdelwahab during this work was carried out.