1,8,10-Substituted Anthracenes – Hexafunctional Frameworks via Head-to-Tail Photodimerisation

Abstract

Several 1,8,10-functionalised anthracene derivatives and a couple of 1,8,9-functionalised anthracene analogous, bearing alkynyl substituents at positions 1 and 8 were synthesised and their photochemistry investigated in UV irradiation experiments. Almost all compounds could be converted into their 9,10:10′,9′-head-to-tail photodimers completely excluding the formation of the corresponding head-to-head isomers. Working under non-inert conditions led to formation of endoperoxides in some cases. Furthermore, a non-classical [4π+2π] photodimer was obtained from 1,8,10-tris[(trimethylsilyl)ethynyl]anthracene with one of the alkynyl substituents involved in the photoreaction. The 1H and 13C NMR spectra of all classical and non-classical photodimers were compared with those of the endoperoxides identifying characteristic shifts for the atoms at positions 9 and 10. Moreover, solid-state structures were determined for one or more of each representative.

A Rational Approach to Tetra‐Functional Photo‐Switches

“…General: 1,8-Dichloroanthracene-10-(9H)-one (1), [14] 1,8-bis[(trimethylsilyl)ethynyl]-10-methylanthracene (2 b), [28] bis[(1,8-dichloroanthracene-10-yl)ethynyl]dimethylsilane (14 b) [29] and 10-bromo-1,8dichloroanthracene [17] were synthesized according to literature protocols. purchased from Sigma Aldrich), N-bromosuccinimide, copper(I) iodide, nickel(II) acetylacetonate (from Acros Organics), dichlorodimethylsilane (from Alfa Aesar), phosphorus pentoxide, palladium/charcoal activated (10 % Pd, oxidic form), AIBN, diisopropylamine (from Merck), Karstedt catalyst (2 % Pt in xylol, from abcr), bis(triphenylphosphine)-palladium(II)dichloride, 1,2-bis(dimethylsilyl)ethane, trimethylsilylacetylene, (from fluorochem) and PPh 3 (from Fluka) were used without further purification.…”

“…General : 1,8‐Dichloroanthracene‐10‐(9 H )‐one ( 1 ), 1,8‐bis[(trimethylsilyl)ethynyl]‐10‐methylanthracene ( 2 b ), bis[(1,8‐dichloroanthracene‐10‐yl)ethynyl]dimethylsilane ( 14 b ) and 10‐bromo‐1,8‐dichloroanthracene were synthesized according to literature protocols. For the syntheses of compounds 2 – 7 , 10 , 12 , 15 , 16 , 1,8‐bis[(trimethylsilyl)ethynyl]‐10‐(bromomethyl)anthracene ( 2 c ), 1,8‐dichloro‐10‐(prop‐1‐yn‐1‐yl)anthracene ( 7 b ), 10,10′‐(prop‐1‐ene‐1,3‐diyl)bis(1,8‐dichloroanthracene) ( 11 b ), its photo‐cyclomer 11b PC and lepidopterene 17 b see Supporting Information.…”