Azodicarboxamides vs. Azodicarboxylates in Reactions against Thioisomunchnones: 1,3-Dipolar Cycloaddition or Nucleophilic Addition?

作者：Sanchez Barbara; Lopez Ignacio; Light Mark E; Silvero Guadalupe; Bravo Jose Luis^*

来源：European Journal of Organic Chemistry, 2010, (9): 1648-1652.

DOI：10.1002/ejoc.200901349

• Azo compounds
• Thioisomunchnones
• Mesoionic compounds
• 1,3-Dipolar cycloadditions
• Thioureas

This communication presents the first study on the use of azodicarboxamides against mesoionic heterocycles as 1,3-dipoles. The reactions yield thioureido compounds. Their formation could be explained, on the basis of experimental results and preliminary theoretical calculations, by a nucleophilic addition followed by rearrangement; however, a formal 1,3-dipolar cycloaddition and subsequent fragmentation and rearrangement of the transient cycloadducts could not be ruled out. Reactions are carried out in refluxing toluene and are complete in 90-240 min. Structural elucidation of the products is based on single-crystal X-ray analysis, as well as other spectroscopic data and 2D-NMR correlations.

• 出版日期2010-3