Synthesis Of Proline Analogues Via Rh-Catalyzed Asymmetric Conjugate Addition

An enantio- and diastereoselective Rh-catalyzed conjugate addition reaction for the synthesis of proline analogues is reported. A high-throughput experimentation campaign was used to identify an efficient chiral catalyst which was able to afford the desired products in high yield and with high levels of diastereo- and enantioselectivity. This method was used to afford a range of 3-substituted proline derivatives from readily available dehydroproline electrophiles and boronic acid nucleophiles.