Azobenzene dye-coupled quadruply hydrogen-bonding modules as colorimetric indicators for supramolecular interactions

• Yagang Zhang and
• Steven C. Zimmerman

Beilstein J. Org. Chem. 2012, 8, 486–495, doi:10.3762/bjoc.8.55

• (DeUG) is described. The coupling of azobenzene dye 2 to mono-amido DAN units 4, 7, and 9 was effected by classic 4-(dimethylamino)pyridine (DMAP)-catalyzed peptide synthesis with N-(3-dimethylaminopropyl)-N’-ethyl carbodiimide hydrochloride (EDC) as activating agent, affording the respective amide

• products 5, 8, and 10 in 60–71% yield. The amide linkage was formed through either the aliphatic or aromatic ester group of 2, allowing both the flexibility and absorption maximum to be tuned. Azobenzene dye 1 was coupled to the DeUG unit 11 by Steglich esterification to afford the product amide 12 in 35

• % yield. Alternatively, azobenzene dye 16 underwent a room-temperature copper-catalyzed azide–alkyne Huisgen cycloaddition with DeUG alkyne 17 to give triazole 18 in 71% yield. Azobenzene coupled DAN modules 5, 8, and 10 are bright orange–red in color, and azobenzene coupled DeUG modules 12 and 18 are

Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R)- and (S)-aminopropanediol as an acyclic linker

• Daniel Lachmann,
• Sina Berndl,
• Otto S. Wolfbeis and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2010, 6, No. 13, doi:10.3762/bjoc.6.13

• ′-deoxyribose substitutes by influencing the stacking orientation of an attached azobenzene dye. The configuration of the linker decides if the dye protrudes towards the major or minor groove, which subsequently leads to an enhanced or diminished stability of the whole DNA duplex [42]. Herein, we want to