Synthesis of gem-Difluoro Olefins through C-H Functionalization and β-fluoride Elimination Reactions
Zhen Yang1, Mieke Möller1, Rene M Koenigs1
1RWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, 52074, Aachen, Germany.
Abstract:
A palladium catalyzed C-H functionalization and consecutive β-fluoride elimination reaction between indole heterocycles and fluorinated diazoalkanes is reported. This approach provides for the first time a facile method for the rapid synthesis of gem-difluoro olefins using fluorinated diazoalkanes under mild reaction conditions. Cyclopropanation products were obtained when N-arylated rather than N-alkylated indoles were applied in this reaction. Mechanistic studies reveal the importance of the β-fluoride elimination step in this transformation. This method presents a new concept for the simple and direct transfer of a 1-aryl-(2,2-difluorovinyl) group to access gem-difluoro olefins.
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