Synthesis 2024; 56(23): 3593-3614
DOI: 10.1055/a-2412-9407
paper

Application of C–H Functionalization in the Construction of Pyrene-Azobenzene Dyads

Sonam Suwasia
,
Sugumar Venkataramani
,
We thank Indian Institute of Science Education and Research Mohali (IISER Mohali) for funding this research work; S.S. thanks IISER Mohali for a PhD fellowship. We also thank the Departmental NMR facility supported by Department of Science and Technology, Ministry of Science and Technology, Fund for Improvement of S&T Infrastructure (DST-FIST; SR/FST/CS-II/2019/94 (TPN No. 32545)).


This paper is dedicated to the late Prof. Ramesh Kapoor (former faculty, IISER Mohali and Panjab University).

Abstract

Herein we report synthesis of pyrene-azobenzene dyads using the Pd(II)-catalyzed directing-group-assisted arylation of the ortho C(sp2)–H bond of pyrenecarboxamides as a key transformation. Many examples of directly connected pyrene-azobenzene dyads (without any linker) and glycine-based azobenzene-pyrene dyads have been synthesized. Initial incorporation of an acetanilide unit in the pyrene skeleton through Pd(II)-catalyzed directing-group-assisted ortho C(sp2)–H arylation by using iodoacetanilide was followed by the transformation of the acetanilide into an azobenzene unit to give the pyrene-azobenzene dyad. UV-Vis spectroscopic studies were performed to get the absorption properties (λmax (nm)) of all the compounds. Preliminary photoswitching studies in both forward and reverse directions and their related thermal reverse ZE isomerization kinetics measurements were ascertained for representative compounds. Considering the importance of pyrene and azobenzene linked motifs as important chromophore-based photoswitchable molecules in chemical, materials, and supramolecular sciences research fields, this work enriches the library of pyrene-azobenzene dyads.

Supporting Information



Publication History

Received: 02 June 2024

Accepted after revision: 10 September 2024

Accepted Manuscript online:
10 September 2024

Article published online:
14 October 2024

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