Photochemical Carbonylation and Hydroformylation (funded by BASF)

Synthesizing amides and esters for the production of agrochemical actives, pharmaceutical actives, and other complicated organic molecules is challenging, as high temperatures need to be applied in current state-of-the-art processes. This often results in limited selectivity and consequently in lower yields and margin of the desired product, in some cases the side products of reactions with limited selectivity will have a negative environmental impact and can even prevent registration of agrochemicals. Novel synthetic approaches are therefore desirable that would yield amides and esters at lower temperatures and with better selectivity. For industrial purposes atom-economic and step-economic processes are desirable, as they can save money and improve sustainability by saving energy for separation, and the disposal of side products through better atom economy and step economy. Moreover, they can make green and bio-derived raw-materials amenable. One particularly attractive way of synthesizing amides and esters is by photochemical carbonylation of aryl-halogenides in the presence of amines or alcohols. This reaction will yield the amide or ester via an intermediate carboxylic acid chloride stage at low temperature and possibly therefore with better selectivity. Moreover, this process is extremely attractive in terms of atom economy and step economy. Photochemistry serves at activating the reatents without the need of putting in heat. The reaction follows a different pathway than the transition metal and opens up a new set of paradigms. Photocatalytic utilization of CO will also be attractive for bulk chemicals produced via classical hydroformylation. Rather than using extremely expensive Rh-based catalysts, in the photochemical pathway H2 and CO to form an aldehyde, a novel, photochemical method will be applied that is based on a different mechanism and therefore has the potential of offering opportunities with regard to selectivity over the state-of-the art. The...