<i>Ortho</i> ‐Carborane‐Derived Halogen Bonding Organocatalysts
Christoph J. Vonnemann, Elric Engelage, Jas S. Ward, Kari Rissanen, Sandro Keller, Stefan M. Huber
Abstract
Abstract Multidentate neutral halogen bonding catalysts based on iodinated icosahedral ortho ‐carborane moieties are introduced. Co‐crystallization‐studies, calorimetric measurements, and 1 H NMR titrations demonstrate their strong binding to halides and neutral compounds, further underlined by quantum‐chemical calculations. Thus, their superior Lewis acidity compared to traditional perfluorinated halogen‐bond donors has been shown. The iodocarborane catalysts also outperformed the latter in a halide abstraction reaction and catalyzed a nitro‐Michael addition reaction, which was previously out of reach for neutral halogen‐bonding‐based organocatalysts.