Recent achievements in synthesis of anthracene scaffolds catalyzed transition metals

Abstract

In the last 10 years, the synthesis of anthracene scaffolds has attracted considerable interest because of their distinctive electronic characteristics and various uses in organic electronics, photovoltaics, and therapeutics. Anthracene, a polycyclic aromatic hydrocarbon, is valued for its lightweight, stability, and electron transport capabilities, making it a key building block in advanced materials. Traditional synthesis methods often face challenges such as low selectivity and harsh conditions. However, recent advancements in transition metal-catalyzed reactions have transformed the field, offering more efficient and versatile approaches. This review examines methodologies utilizing transition metal catalysts like palladium, zinc, indium, cobalt, gold, iridium, rhodium and ruthenium, which have enabled novel synthetic pathways and selective formation of substituted anthracenes through cross-coupling reactions. The function of ligands, including phosphines and N-heterocyclic carbenes, in improving reaction efficiency and selectivity is also examined. The shift towards greener methodologies is noted, with a focus on minimizing waste and reducing toxic reagents. The shift towards greener methodologies is noted, with a focus on minimizing waste and reducing toxic reagents. Several case studies demonstrate the successful application of these techniques, highlighting the structural diversity and functional potential of anthracene derivatives in various applications.

Keywords: anthracene; catalyst; nanocatalys; synthesis; transition metals (Cr and Fe).

FIGURE 1

Some of anthracene derivatives.

SCHEME 1

Synthesis of tetracyclic benz [a] anthracenes through palladium-catalyzed tandem C-H activation/biscyclization reaction of propargylic carbonates with terminal alkynes.

SCHEME 2

The plausible mechanism of Synthesis of tetracyclic benz [a]anthracenes through palladium-catalyzed tandem C-H activation/biscyclization reaction of propargylic carbonates with terminal alkynes.

SCHEME 3

Synthesis of 6,8-diiododi-benzo [a,j]anthracenes through a multistep synthetic approach in the presence of catalytic amount of palladium.

SCHEME 4

Synthesis of dibenz [a,h]anthracenes through Pd-catalyzed intramolecular double-cyclization of the corresponding (Z, Z)-p-styrylstilbene derivatives.

SCHEME 5

Synthesis and a plausible mechanism of synthesis of substituted anthracene derivatives through Pd(II)-catalyzed sp³ C–H alkenylation of diphenyl carboxylic acids with acrylates.

SCHEME 6

Synthesis of 2,3,5,6-tetraalkoxydi-benz [a,c]anthracenes through Pd(PPh₃)₄ catalyzed Suzuki coupling of the appropriate dibromonaphthalene and boronate ester, followed by an oxidative cyclization.

SCHEME 7

Synthesis of substituted anthracenes through Pd(I I)-Catalyzed sp³ C-H arylation and electrophilic aromatic cyclization.

SCHEME 8

Synthesis of anthraquinones through [Pd]-catalyzed intermolecular direct acylation reaction.

SCHEME 9

Synthesis of 9,10-diarylanthracene derivatives through ZnBr₂/SiO₂ catalyzed reaction of electron-rich arenes with aromatic aldehydes and acetyl bromide.

SCHEME 10

Synthesis of 9,10-diacetoxy-anthracenes through from anthraquinone and its derivatives via a single step reaction by using reductive Zn-pyridine system.

SCHEME 11

Synthesis of anthraquinone derivatives through Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroylpropiolates followed by intramolecular Friedel-Crafts cyclization.

SCHEME 12

Synthesis of 1,8 -diaryl-anthracene derivatives from anthroquinones in the presence of zinc as the catalyst.

SCHEME 13

Synthesis of anthracenes through zinc bromide catalyzed one-pot regioselective annulation of unsymmetrical 1,2-phenylenebis (diaryl/diheteroarylmethanol).

SCHEME 14

Synthesis and mechanistic rationale pathway of anthraquinone derivatives through cyclocondensation of aldehydes, β-naphthol and cyclic 1,3-di-carbonyl compounds catalyzed by InCl₃.

SCHEME 15

Synthesis of anthracene derivatives from 2-benzylic- or 2-allylbenzaldehydes using a catalytic amount of In(III) or Re(I) complexes.

SCHEME 16

Synthesis and mechanistic rationale pathway of cytotoxic dibenzo [a,h]anthracenes through InCl3 catalyzed one-pot three-component reaction with 2-hydroxy-1,4-naphthoquinone, aromatic aldehydes, and 2-naphthol.

SCHEME 17

Synthesis of substituted anthracenes and azaanthracenes through Nickel/cobalt catalyzed [2 + 2 + 2] cyclotrimerization reactions.

SCHEME 18

Synthesis of substituted anthracenes through oCl₂·6H₂O/Zn reagent catalyzed [2 + 2 + 2] cycloaddition reaction of 1,6-diynes with 4-aryl-2-butyn-1-ols.

SCHEME 19

Synthesis of 2,3- and 2,3,6,7-halogenated anthracenes through cobalt-catalyzed [2 + 2 + 2] cyclotrimerization reactions with bis(trimethylsilyl)acetylenes.

SCHEME 20

Synthesis of dibenzo [a, h]anthracenes through one-pot double cyclization reactions in the presence of catalytic amount of AuCl.

SCHEME 21

Synthesis of substituted anthracenes through gold catalyzed cyclization of o-alkynyldiarylmethanes.

SCHEME 22

Synthesis of anthraquinone derivatives through [Ir (cod)Cl]₂/DPPE catalyzed [2 + 2 + 2] cycloaddition of a 1,2-bis(propiolyl)benzene derivative with terminal and internal alkynes.

SCHEME 23

Synthesis of 1,2,3,4-tetrasubtituted anthracene derivatives through rhodium-catalyzed oxidative coupling reactions of aryl-boronic acids with internal alkynes in the presence of Cu(OAc)₂ as the oxidant.

SCHEME 24

Synthesis of substituted anthracenes through rhodium-catalyzed oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal alkynes in the presence of Cu(OAc)₂ as the oxidant.

SCHEME 25

Synthesis of dibenzo [a,h] anthracenes through [RuH₂(CO) (PPh₃)] catalyzed one-pot regioselective C¬H arylation of aromatic ketones.