Rare Earth Triflate/Alanine Catalysed Diels-Alder and Michael Reactions in Water and an Alternative Pyrrole Synthesis

Abstract: Large amounts of organic solvents are used within the field of chemistry and nearly everything is being discarded and is not reused. A way to reduce the environmental impact that this leads to is to use a safe and natural solvent that is easy to access, like water. In this project, Diels-Alder and Michael reactions were carried out in an aqueous medium with rare earth triflates and alanine as catalytic system. Most of the Diels-Alder reactions were slow, and a good reaction rate was only reached in one of the reactions. The Michael reactions with methyl 2-nitroacetate as Michael donor were much faster, and all the performed reactions worked with high to moderate reaction rates. The Michael adducts were then used to demonstrate a short and convenient pyrrole synthesis route that with some optimisations of work up and purification could be a good alternative to the more conventional pyrrole synthesis methods used in industry and science today.