Cover Feature: Programmed Site-Selective Palladium-Catalyzed Arylation of Thieno[3,2 -b]thiophene (Chem. Asian J. 21/2017).

An efficient and straightforward method for the synthesis of multi ‐ arylated thieno[3,2 ‐ b]thiophene is reported. The direct site ‐ selective arylation of 2 ‐ arylthieno[3,2 ‐ b]thiophene takes place at predictable positions (i.e., at the C ‐ 3 or C ‐ 5 position) depending on the nature and the size of the 2 ‐ aryl substituents. If the 2 ‐ aryl substituent bears an electron ‐ withdrawing group, the next arylation takes place at the C ‐ 3 position. On the other hand, if the 2 ‐ aryl substituent bears an electron ‐ donating group, the next arylation takes place at the C ‐ 5 position. More information can be found in the Full Paper by Tung Thanh Dang, Hien Nguyen et   al. on page   2819 in Issue 21, 2017 (DOI:10.1002/asia.201700562). [ABSTRACT FROM AUTHOR]