Synthesis of substituted pyrenes by indirect methods

Abstract

The pyrene nucleus is a valuable component for materials, supramolecular and biological chemistry, due to its photophysical/electronic properties and extended rigid structure. However, its exploitation is hindered by the limited range of methods and outcomes for the direct substitution of pyrene itself. In response to this problem, a variety of indirect methods have been developed for preparing pyrenes with less usual substitution patterns. Herein we review these approaches, covering methods which involve reduced pyrenes, transannular ring closures and cyclisations of biphenyl intermediates. We also showcase the diverse range of substituted pyrenes which have been reported in the literature, and can serve as building blocks for new molecular architectures.

Recent developments in and perspectives on three-coordinate boron materials: a bright future

“…89,90 Thus, pyrene and its derivatives have been widely employed in numerous applications. Interestingly, however, both the HOMO and the LUMO of pyrene possess a nodal plane perpendicular to the molecular plane and passing through carbon atoms 2 and 7 (Scheme 2) lying along the long molecular 2-fold axis.…”

Pyrene Molecular Orbital Shuffle—Controlling Excited State and Redox Properties by Changing the Nature of the Frontier Orbitals

“…Consequently, these positions are difficult to functionalize directly through typical aromatic substitution chemistry and, until recently, circuitous routes were the only ones available for 2‐ or 2,7‐substituted pyrenes. Thus, most pyrene derivatives are functionalized at one or more of the 1‐, 3‐, 6‐, and 8‐positions, as these are the sites of maximum contributions of the HOMO (and LUMO) and consequently those at which electrophilic (and nucleophilic) substitution take place …”

Pyrene-benzothiadiazole-based copolymers for application in photovoltaic devices

“…Furthermore, the electron‐rich nature of pyrene means that the pyrene unit can be polymerized with electron‐deficient units forming the advantageous D–A arrangement discussed earlier. The pyrene unit can be polymerized through the 2,7‐positions . Furthermore, the optical and electronic properties of pyrene units can be altered by functionalizing the 4,5,9,10‐positions of pyrene with different substituents.…”