Development and mechanistic investigations of efficient Fe-catalysed asymmetric C–H activation

ended

The importance of chirality in bioactive molecules is well established with only one enantiomer exhibiting the desired biological activity. To date, more than 90% of chiral drugs on the market are supplied as racemates potentially causing side-effects or of uncertain bioactivity. The enantioselective synthesis of chemicals has risen to address such issues with enantioselective catalytic C–H activation standing out due to its atom economy, step efficiency, and avoidance of substrate pre-functionalization. So far, metal-catalysed enantioselective inner sphere C–H activation relies mainly on precious and/or toxic metals, such as Pd and Ru, limiting the reaction’s applicability. Therefore, efforts are currently being made to replace such metals with more benign 3rd row transition metals. Nevertheless, only one report of such transformation has been reported with Fe despite Fe being extremely desirable due to its low cost, toxicity and high natural abundance. The AsymFeCH project will address this issue through the development of non-toxic, sustainable and inexpensive Fe-catalysed enantioselective C–H activation reactions. For this purpose, low valent Fe complexes with chiral phosphines will be used as precatalysts in the catalytic hydroarylation of allenes or alkenes with aromatic ketones. The mechanism and origin of enantioselectivity of the developed reactions will then be delineated through a unique combination of spectroscopies and kinetic studies. Subsequently, the acquired mechanistic understanding will be used for further reaction development with more challenging substrates (imines and 1,1-diphenylketone derivatives) setting the foundations for the scientific and industrial communities to advance the field of asymmetric Fe-catalysed C-H activation. This will not only lead to the sustainable and greener synthesis of pure chiral products affecting the pharmaceutical and materials sectors but will also make Europe less dependent on Pd, an imported precious metal.