Intramolecular hydrogen bonding guides a cationic amphiphilic organocatalyst to highly stereoselective aldol reactions in water†
Abstract
A novel amphiphilic guanidine organocatalyst, efficient for asymmetric aldol reactions of ketones in water at neutral pH, is disclosed. The reaction presented a clear substrate dependence depicting a free energy linear correlation with ee. Intramolecular hydrogen bonding in the acylguanidine moiety was identified as the key structural motif.