Short-step synthesis and chiroptical properties of polyaza[5]-[9]helicenes with blue to green-colour emission

Chem Commun (Camb). 2020 Apr 25;56(32):4484-4487. doi: 10.1039/d0cc01194k. Epub 2020 Mar 23.

Abstract

We have developed a two- or three-step synthesis of polyaza[5]-[9]helicenes by consecutive N-H/C-H coupling with a hypervalent iodine reagent. We further evaluated their photophysical properties, and circularly polarized luminescence properties and found that glum values increase with the number of fused rings up to 2.7 × 10-2, which is the highest value among [9]helicenes.