One-pot reactions in catalysis: a valuable tool for the synthesis of enantiopure intermediates for pharmaceutical applications

One-pot reactions stand out as processes in which several sequential reactions are conducted in a single reaction vessel and most importantly each reaction can only start after the previous one is completed thus leading to the desired final product without the need of any purification of the intermediates. This approach allows in principle to shorten the total synthesis time and generally leads to an increase in the total yield and to a reduction in the amount of chemical waste formed, resulting beneficial from an environmental point of view (Acc. Chem. Res. 2021, 54, 6, 1385–1398). Starting from these concepts of time and pot economy, the combo of chemo- and biocatalytic approach-based on a copper catalyst and Rhodotorula rubra yeast respectively- was applied to the stereoselective synthesis of key intermediates such as 1,3 diols in excellent enantio- and diastereomeric excess (ChemistryOpen 2018, 7, 393-400) . Following the same successful approach, we have recently developed a one-pot reaction in two steps for the preparation of enantio-enriched 3,3-azaaryl-1-aryl-propanols and 3,3-azaaryl-1-alkyl-propanols containing a pyridine core. After the enantioselective addition of the phenylboronic acid to 3-azaarylprop-2-en-1-ones obtained in good yields and enantiopurity by exploiting a chiral rhodium-diphosphine catalyst (New J. Chemistry 2021, 45, 18769-18775), the subsequent carbonyl reduction was carried out by a ruthenium complex for the aryl derivatives or by a Tourolopsis genera yeast in the case of the alkyl compounds, thus affording the desired products, key intermediates for pharmaceutical applications.