N-Carbamate Protected Amino Acid Derived Guanidine Organocatalysts

We report the preparation of a range of N-protected amino acid derived guanidine organocatalysts and their application to the Michael addition of 2-hydroxy-1,4-napthoquinone to beta-nitrostyrene, achieving a maximum ee of 26%. Whilst these catalysts gave poor ees, the structural variation together with the X-ray crystallographic study of the intra- and intermolecular hydrogen bonding reported suggest that the C-2-symmetric catalysts are lead compounds for the further development of this methodology. (C) 2021 Published by Elsevier Ltd.