Yamamoto Coupling for the Synthesis of Benzophenes and Acene‐Based Cyclooctatetraenes

Abstract

Two TIPS-ethynylated dibromoacenes were used in a shotgun Yamamoto-reaction with 1,2-dibromobenzene or 4,5-dibromoveratrol. Four soluble benzononaphenes/benzoundecaphenes were isolated in satisfactory yields. Examples of tetracene- and pentacene-fused tetrabenzocyclooctatetraenes also isolated from this reaction are reported. All compounds were characterized by UV/Vis and fluorescence spectroscopy, cyclic voltammetry, X-ray crystallography as well as DFT and NICS calculations.

Selective access to either a doubly boron-doped tetrabenzopentacene or an oxadiborepin from the same precursor

“…of [(bpy)Ni 0 ] and produces Ar-Ar (in DMF). 25 None of these scenarios, however, accounts for empirical observations made by us and others, 18,22,[68][69][70] namely, that the addition of excess COD ligand and of 2 equiv. rather than 1 equiv.…”

Starphenes and Phenes: Structures and Properties

“…Preparative recycling gel-permeation chromatography cleanly separated a number of different compounds otherwise difficult to access (Figure 9). 57 Some features should be noted: we find not only trimeric benzophenes such as T 2 B and TB 2 or P 2 B and PB 2 , but also cyclotetramers such as TB 3 and PB 3 or T 2 V 2 and PVPV. Although we use an excess of the benzene or veratrole derivative, the T 2 -and P 2 -products are more abundant than Figure 7 adapted with permission from Rüdiger et al 63 Copyright 2018 John Wiley and Sons.)…”

“…Figure10Photographs of phenes T 2 B, T 2 V, P 2 B, and P 2 V in n-hexane at room temperature (top); UV-vis spectra of T 2 B and P 2 B (bottom) are similar to those reported by Clar for unsubstituted phenes. (Adapted with permission from Rüdiger et al57 Copyright 2018 John Wiley and Sons. )…”

“…Calculated with Gaussian09 [B3LYP/6-311 þ þG(d,p)], geometry optimization with TURBOMOLE (BP86 def2-TZVP). (Reprinted with permission from Rüdiger et al57 Copyright 2018 John Wiley and Sons. )…”

Benzo‐fused Tri[8]annulenes as Molecular Models of Cubic Graphite

“…The least intense absorption features at long wavelengths ( λ max,abs =356/358 nm) were similar to those of phenanthrene, [27] the largest π‐conjugated subunit in both compounds—COT‐annulation did not lead to a pronounced red‐shift. [28] 7 a and 7 b fluoresced violet‐blue at λ max,em =360/365 nm. [29]…”