Synthetic reactions driven by electron-donor-acceptor (EDA) complexes

Abstract

The reversible, weak ground-state aggregate formed by dipole-dipole interactions between an electron donor and an electron acceptor is referred to as an electron-donor-acceptor (EDA) complex. Generally, upon light irradiation, the EDA complex turns into the excited state, causing an electron transfer to give radicals and to initiate subsequent reactions. Besides light as an external energy source, reactions involving the participation of EDA complexes are mild, obviating transition metal catalysts or photosensitizers in the majority of cases and are in line with the theme of green chemistry. This review discusses the synthetic reactions concerned with EDA complexes as well as the mechanisms that have been shown over the past five years.

Keywords: EDA complex; electron acceptor; electron donor; radical; visible light.

Scheme 1

The electron transfer process in EDA complexes.

Scheme 2

Synthesis of benzo[b]phosphorus oxide 3 initiated by an EDA complex.

Scheme 3

Mechanism of the synthesis of quinoxaline derivative 7.

Scheme 4

Synthesis of imidazole derivative 10 initiated by an EDA complex.

Scheme 5

Synthesis of sulfamoylation product 12 initiated by an EDA complex.

Scheme 6

Mechanism of the synthesis of sulfamoylation product 12.

Scheme 7

Synthesis of indole derivative 22 initiated by an EDA complex.

Scheme 8

Synthesis of perfluoroalkylated pyrimidines 26 initiated by an EDA complex.

Scheme 9

Synthesis of phenanthridine derivative 29 initiated by an EDA complex.

Scheme 10

Synthesis of cis-tetrahydroquinoline derivative 32 initiated by an EDA complex.

Scheme 11

Mechanism of the synthesis of cis-tetrahydroquinoline derivative 32.

Scheme 12

Synthesis of phenanthridine derivative 38 initiated by an EDA complex.

Scheme 13

Synthesis of spiropyrroline derivative 40 initiated by an EDA complex.

Scheme 14

Synthesis of benzothiazole derivative 43 initiated by an EDA complex.

Scheme 15

Synthesis of perfluoroalkyl-s-triazine derivative 45 initiated by an EDA complex.

Scheme 16

Synthesis of indoline derivative 47 initiated by an EDA complex.

Scheme 17

Mechanism of the synthesis of spirocyclic indoline derivative 47.

Scheme 18

Synthesis of cyclobutane product 50 initiated by an EDA complex.

Scheme 19

Mechanism of the synthesis of spirocyclic indoline derivative 50.

Scheme 20

Synthesis of 1,3-oxazolidine compound 59 initiated by an EDA complex.

Scheme 21

Synthesis of trifluoromethylated product 61 initiated by an EDA complex.

Scheme 22

Synthesis of indole alkylation product 64 initiated by an EDA complex.

Scheme 23

Synthesis of perfluoroalkylation product 67 initiated by an EDA complex.

Scheme 24

Synthesis of hydrotrifluoromethylated product 70 initiated by an EDA complex.

Scheme 25

Synthesis of β-trifluoromethylated alkyne product 71 initiated by an EDA complex.

Scheme 26

Mechanism of the synthesis of 2-phenylthiophene derivative 74.

Scheme 27

Synthesis of allylated product 80 initiated by an EDA complex.

Scheme 28

Synthesis of trifluoromethyl-substituted alkynyl product 84 initiated by an EDA complex.

Scheme 29

Synthesis of dearomatized fluoroalkylation product 86 initiated by an EDA complex.

Scheme 30

Mechanism of the synthesis of dearomatized fluoroalkylation product 86.

Scheme 31

Synthesis of C(sp³)–H allylation product 91 initiated by an EDA complex.

Scheme 32

Synthesis of perfluoroalkylation product 93 initiated by an EDA complex.

Scheme 33

Synthesis of spirocyclic indolene derivative 95 initiated by an EDA complex.

Scheme 34

Synthesis of perfluoroalkylation product 97 initiated by an EDA complex.

Scheme 35

Synthesis of alkylated indole derivative 100 initiated by an EDA complex.

Scheme 36

Mechanism of the synthesis of alkylated indole derivative 100.

Scheme 37

Synthesis of arylated oxidized indole derivative 108 initiated by an EDA complex.

Scheme 38

Synthesis of 4-ketoaldehyde derivative 111 initiated by an EDA complex.

Scheme 39

Mechanism of the synthesis of 4-ketoaldehyde derivative 111.

Scheme 40

Synthesis of perfluoroalkylated olefin 118 initiated by an EDA complex.

Scheme 41

Synthesis of alkylation product 121 initiated by an EDA complex.

Scheme 42

Synthesis of acylation product 123 initiated by an EDA complex.

Scheme 43

Mechanism of the synthesis of acylation product 123.

Scheme 44

Synthesis of trifluoromethylation product 126 initiated by an EDA complex.

Scheme 45

Synthesis of unnatural α-amino acid 129 initiated by an EDA complex.

Scheme 46

Synthesis of thioether derivative 132 initiated by an EDA complex.

Scheme 47

Synthesis of S-aryl dithiocarbamate product 135 initiated by an EDA complex.

Scheme 48

Mechanism of the synthesis of S-aryl dithiocarbamate product 135.

Scheme 49

Synthesis of thioether product 141 initiated by an EDA complex.

Scheme 50

Mechanism of the synthesis of borate product 144.

Scheme 51

Synthesis of boronation product 148 initiated by an EDA complex.

Scheme 52

Synthesis of boration product 151 initiated by an EDA complex.

Scheme 53

Synthesis of boronic acid ester derivative 154 initiated by an EDA complex.

Scheme 54

Synthesis of β-azide product 157 initiated by an EDA complex.

Scheme 55

Decarboxylation reaction initiated by an EDA complex.

Scheme 56

Synthesis of amidated product 162 initiated by an EDA complex.

Scheme 57

Synthesis of diethyl phenylphosphonate 165 initiated by an EDA complex.

Scheme 58

Mechanism of the synthesis of diethyl phenylphosphonate derivative 165.

Scheme 59

Synthesis of (Z)-2-iodovinyl phenyl ether 168 initiated by an EDA complex.

Scheme 60

Mechanism of the synthesis of (Z)-2-iodovinyl phenyl ether derivative 168.

Scheme 61

Dehalogenation reaction initiated by an EDA complex.