Chemistry Reference
In-Depth Information
Scheme 23 Examples of graphene-type structures assembled by trimerization of triphenylynes
[
56
,
57
]
In an analogous strategy, new graphene-type structures could be realized
employing arynes as alkyne partners. The trimerization of naphtalyne and
triphenylyne generated from the corresponding
-trimethylsilyl triflates gave
various PAHs 97-99, 101 as shown in Scheme
23
[
56
,
57
].
ortho
2.4 Aryl-Aryl-Coupling Reactions
2.4.1 Cross-Coupling Reactions
Without doubt, transition metal catalyzed cross-coupling reactions are one of the
most efficient ways to join two aromatic fragments. This has also been recognized
by awarding the Nobel Prize to Heck, Noyori, and Suzuki in 2010. Hence, it is not
surprising that it has been used extensively to assemble PAHs. There have been
numerous reviews on cross-coupling reactions. Therefore, the topic will not be
elaborated on further here, despite the extraordinary importance of cross-coupling
reactions [
58
-
61
]. In the area of molecular electronics, PAHs have been assembled
by cross-coupling reactions for use in organic field effect transistors [
62
]. The
effectiveness of this methodology is demonstrated by the examples shown below
(Scheme
24
)[
63
]. Twofold Suzuki coupling of the dibromoanthracene 104 with
boronic ester 103 yielded trimer 105 (Scheme
25
).
