Synthesis and Kinectic Studies of Novel Aminocatalysts

The insertion of N-heterocyclic side chains in the MacMillan and Jørgensen-Hayashi organocatalysts aims to obtain structures with higher catalytic efficiency (better turnover number and frequency, TON and TOF) and selectivity. The modified imidazolidinones were synthesized using either L-serine or L-phenylalanine as chiral pools and isolated as free amines, providing liberty to add any desired acid co-catalysts.

The influence of electron withdrawing and donating groups in the imidazolidinone modification at the amide group is currently being investigated using Linear Free Energy Relationships (LFER). Meanwhile, a modification in which heterocyclic side-chain was introduced was tested in known organocatalyzed reactions to compare enantio- and diastereoselectivity with the original MacMillan catalyst. The modified diarilprolinol silyl ether synthesis is being studied by introducing heteroaromatics side-chains via Grignard addition to the ethyl ester of N-Boc-L-proline. The side chain addition should enable adjustment in acid-base processes typically involved in organocatalytic condensation and hydrolysis steps.