투고논문

Intramolecualr cyclization of a dipyrromethane by an electrophilic aromatic substitution reaction producing a new chiral compound

Seung Hyun Kim and Sung Kuk Kim*

Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea

Received Dec 1, 2018; Revised Dec 10, 2018; Accepted Dec 13, 2018

Abstract

Dipyrromethane 2 functionalized with 3-chloropropyl group on the meso carbon undergoes an unusual intramolecular electrophilic aromatic substitution reaction in the presence of NaN3 instead of a simple nucleophilic substitution reaction. As a result, a new chiral dipyrromethane 1 was synthesized. In this reaction, the β-carbon of the pyrrole ring functions as a nucleophile while the carbon next to the chlorine atom acts as an electrophile. Interestingly, this reaction progresses even in the absence of an acid catalyst. Compound 1 was fully characterized by 1H-1H and 1H-13C COSY NMR spectroscopic analyses and the high resolution EI mass spectrometry.

* Address correspondence to: Sung Kuk Kim, Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea; Tel: 82-55-772-1494; E-mail: sungkukkim@gnu.ac.kr