Self-organizing oligothiophene-nucleoside conjugates: versatile synthesis via "click"-chemistry.

A versatile synthesis of novel oligothiophene-nucleoside conjugates based on Cu(I)-catalyzed alkyne-azide cycloaddition ("click-reaction") has been developed. Complementary thymidine- and adenosine-functionalized quaterthiophenes form recognition-driven superstructures via hydrogen bonding and other competing intermolecular forces. Self-aggregated fibers up to 30 microm in length were characterized with atomic force microscopy.

A nucleophilic Fe catalyst for transesterifications under neutral conditions.

Carboxylic esters belong to the most important functional groups in organic chemistry. Strong efforts have been made in developing mild catalytic procedures for their preparation. Among the various methods developed to date, transesterifications have occupied an important space. In the present paper, a new catalytic method for this process based on the use of nucleophilic Fe(-II) complexes is presented. Evidence for the formation of an intermediate acyl Fe complex will be presented as well as investigations on scope and limitations.