Rh-Catalyzed Direct Carboxylation of Alkenyl C?H Bonds of Alkenylpyrazoles

Article abstract of DOI:10.1002/asia.202000476

The Rh-catalyzed direct carboxylation of alkenyl C?H bonds was achieved by using pyrazole as a removable directing group. In the presence of 5 mol% RhCl₃ ? 3H₂O, 6 mol% P(Mes)₃, and 2 equiv. of AlMe₂(OMe), the alkenyl C?H bond of various alkenylpyrazoles was directly carboxylated in good yields under CO₂ atmosphere. Furthermore, several useful transformations of the pyrazole moiety of the product were achieved to afford synthetically useful carboxylic acid derivatives in good yields.