Synthesis of toxyloxanthone B
A synthesis of the naturally occurring xanthone toxyloxanthone B is described, in which the key step is the regioselective addition of a methyl salicylate to a substituted benzyne, followed by cyclization of the intermediate aryl anion to form the xanthone, the regiochemistry of the aryne addition being confirmed by X-ray crystallography. Subsequent introduction of the pyran ring by [3,3]-rearrangement and deprotection completed the synthesis.
Synthesis and thermoelectric properties of 2- and 2,8-substituted tetrathiotetracenes
Reaction of elemental sulfur with 2-R1 and 2,8-R1,R2-substituted tetracenes (2) in refluxing DMF affords 5,6,11,12 tetrathiotetracenes (1) in good yields (74–99%) for a range of substituents where R1,R2 are: H,H (a); Me,H (b); MeO,H (c); Ph,H (d); Me,Me (e), iPr,Me (f, iPr = iso-propyl, CHMe2), Me,MeO (g); MeO,MeO (h). The reaction rate is limited only by the solubility of the tetracene (2); 2g–h being both the least soluble and slowest reacting. At partial conversion recovered single crystalline 2g led to its X-ray structure determination. Vacuum deposited (substrate deposition temperature 300 K, pressure 7 × 10−6 mbar, source temperature 500 K) thin films from 1 (of initial 88–99% purity)…
CCDC 973933: Experimental Crystal Structure Determination
Related Article: Daniele Giallombardo, Adam C. Nevin, William Lewis, Christopher C. Nawrat, Russell R. A. Kitson and Christopher J. Moody|2014|Tetrahedron|70|1283|doi:10.1016/j.tet.2013.12.055
CCDC 1811026: Experimental Crystal Structure Determination
Related Article: Mary Robert Garrett, María Jesús Durán-Peña, William Lewis, Kaspars Pudzs, Jānis Užulis, Igors Mihailovs, Björk Tyril, Jonathan Shine, Emily F. Smith, Martins Rutkis, Simon Woodward|2018|J.Mater.Chem.C|6|3403|doi:10.1039/C8TC00073E