Exploring the Selectivity of Iridium Catalysed Arene Borylation

1. Scheme 1 The reaction was set up in a glove box to prevent contact with the air. Exploring the Selectivity of Iridium Catalysed Arene Borylation Simon Kenwright – Nuffield Bursary Aug 2011 - Dr P G Steel Research Group - Durham University Substituted aromatic molecules have important roles in many aspects of life, including pharmaceuticals, smart sensors and polymers. A challenge in making these molecules lies in the activation of the aromatic C-H bond. Replacing a C-H bond with a C-B bond is a popular solution to this problem. Traditional methods of doing this generate considerable amounts of waste and new, clean catalytic methods are needed. This project aimed to evaluate a new catalyst (silica SMAP-Ir), claimed to provide high selectivity of the site at which the borylation takes place during this process. This poster describes an attempt to evaluate this catalyst and its effects with chlorobenzene. The reaction was then stirred at 50°C and monitored at periods of 19h, 24h and 43h. After 43h the reaction was stopped through the addition of Dichloromethane. The reaction was then analysed using GCMS (gas chromatography and mass spectrometry) and NMR (Nuclear Magnetic Resonance) spectroscopy. The GCMS analysis showed 58% of the reaction mixture was desired product Filling a balloon with argon to evacuate a vial of air and moisture Weighing out solid starting materials into a vial This demonstrates how the new catalyst gives good ortho selectivity and thus can be used to produce specific molecules that would otherwise be difficult/impossible to produce. This product was then isolated and purified using chromatography.