Highly Regioselective Direct C-H Arylation: Facile Construction of Symmetrical Dithienophthalimide-Based π-Conjugated Molecules for Optoelectronics.

Xiang-Chun Li,Yibo Xue,Jie Min,Wei Huang,Fang Liu,Wen-Yong Lai,Xu Liu,Yu Yan,Wan Song

doi:10.34133/2020/9075697

Abstract

Controllable direct C-H arylation with high regioselectivity is highly desirable yet remains a formidable challenge. Herein, a facile regioselective direct C-H arylation is developed for efficient construction of a variety of symmetrical dithienophthalimide-based π-conjugated molecules. The resulting methodology is applicable to a wide range of substrates, from electron-rich units to electron-deficient units with large steric end groups. Aryl halides have been confirmed to be able to couple with dithienophthalimide (DTI) via direct C-H arylation, showing high regioselectivity. Varying the functional end groups onto the DTI core has been demonstrated to fine tune the emission colors to cover most of the visible spectra. The results suggest a facile strategy towards highly selective direct C-H arylation, opening the prospects towards efficient construction of π-conjugated molecules for various potential optoelectronic applications.

Highlights

Organic π-conjugated molecules have been intensively explored over recent years for various potential applications, i.e., as active materials for organic light-emitting diodes (OLEDs) [1,2,3,4,5,6,7], organic photovoltaics [8,9,10], organic fieldeffect transistors [11,12,13,14], organic semiconductor lasers [15,16,17,18,19], theranostics [20,21,22], etc
The results suggest a facile strategy towards highly selective direct C-H arylation for the efficient construction of various π-conjugated molecules based on DTI for optoelectronic applications
Varying the functional end groups onto the DTI core has been demonstrated to fine tune the emission colors to cover most of the visible spectra, which are potential active materials for organic optoelectronics, i.e., OLEDs

Summary

Introduction

Organic π-conjugated molecules have been intensively explored over recent years for various potential applications, i.e., as active materials for organic light-emitting diodes (OLEDs) [1,2,3,4,5,6,7], organic photovoltaics [8,9,10], organic fieldeffect transistors [11,12,13,14], organic semiconductor lasers [15,16,17,18,19], theranostics [20,21,22], etc. Even a small number of structural defects could result in a sharp decline in the optoelectronic characteristics [54,55,56] For these reasons mentioned above, the selectivity and regioselectivity issues have been considered the Achilles heel of C-H arylation. All the DTI-based π-conjugated molecules are easy to synthesize and functionalize in a practical, high yield, and selective synthetic pathway, which is beneficial for establishing a library of organic optoelectronic materials with emission wavelengths covering most of the visible spectra. The results suggest a facile strategy towards highly selective direct C-H arylation for the efficient construction of various π-conjugated molecules based on DTI for optoelectronic applications

Results

Discussion

Conflicts of Interest