Retraction: Cobalt‐Catalyzed Temperature‐Dependent Annulation of 3‐Aryl‐1,2,4‐oxadiazolones with 1,3‐Diynes: An Approach to π‐Conjugated Molecules

The above article in Advanced Synthesis & Catalysis, published online on November 28, 2018, in Wiley Online Library (onlinelibrary.wiley.com), and in print Volume 361, Issue 12, 2019, pages 2885–2896 (DOI: 10.1002/adsc.201801165), has been retracted by agreement between the authors, the journal Editor, Joe P. Richmond, and Wiley-VCH Verlag GmbH & Co. KGaA. The retraction has been agreed to for the following reasons. After publication, a reader pointed out that the structure of 4 c in Scheme 3 does not correspond to the crystal structure in the same Scheme: all the structures shown in Scheme 3 are 4-alkynylisoquinolines, whereas the crystal structure is that of a 3-alkynylisoquinoline. Nevertheless, the products in Scheme 2, obtained at a lower temperature, are formed via a 4-alkynylisoquinoline intermediate. The regioselectivity of the products in Scheme 2 are different from those in Scheme 3. Therefore, the mechanism in Scheme 6 is also wrong. The authors could not find an explanation for the different regioselectivities found for the similar reactions reported in Schemes 2 and 3, in spite of literature searches, computational calculations, and control experiments.