Efficient Synthesis of 1,5‐Benzodiazepine Derivatives by Ytterbium Trichloride–Catalyzed Condensation of o‐Phenylenediamine and Ketones

Abstract

1,5‐Benzodiazepines are synthesized in good to excellent yields by ytterbium trichloride (YbCl₃)–catalyzed condensation of o‐phenylenediamine and ketones under mild and solvent‐free conditions. The Lewis acid–type catalyst, ytterbium trichloride, is found to be water stable and reusable.

Keywords:

• 1,5‐Benzodiazepine
• catalysis
• lanthanide
• synthesis
• ytterbium trichloride

Acknowledgment

We thank the National Science Foundation of China (Grant No. 20272040), State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, and Key Laboratory of Organic Synthesis of Jiangsu Province for financial support.