Electro‐Mechanochemical Atom Transfer Radical Cyclizations using Piezoelectric BaTiO3

Angewandte Chemie International Edition, vol. 59, pp. 16357–16360

Abstract

Abstract The formation and regeneration of active CuI species is a fundamental mechanistic step in copper‐catalyzed atom transfer radical cyclizations (ATRC). Typically, the presence of the catalytically active CuI species in the reaction mixture is secured by using high CuI catalyst loadings or the addition of complementary reducing agents. In this study it is demonstrated how the piezoelectric properties of barium titanate (BaTiO3) can be harnessed by mechanical ball milling to induce electrical polarization in the strained piezomaterial. This strategy enables the conversion of mechanical energy into electrical energy, leading to the reduction of a CuII precatalyst into the active CuI species in copper‐catalyzed mechanochemical solvent‐free ATRC reactions.

Authors 3

1. Christian Schumacher Aachen Institute of Organic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Organic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany

   Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

2. José G. Hernández corresponding Aachen Institute of Organic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Organic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany

   Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

3. Carsten Bolm corresponding Aachen Institute of Organic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Organic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany

   Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany