Disulfonimide-Catalyzed Asymmetric Synthesis of β3-Amino Esters Directly from N-Boc-Amino Sulfones
摘要:
An asymmetric Mannich reaction of silyl ketene acetals with N-Boc-amino sulfones has been developed. A chiral disulfonirnide efficiently catalyzes both the in situ generation of the corresponding N-Boc imines and the asymmetric Mannich reaction with excellent yields and enantioselectivities. Kinetic studies confirm a proposed stepwise mechanism.
synthetic equivalents of a variety of α‐carboxylate anions. Phase‐transfer catalysis (PTC) enabled their mild deprotonation and catalytic asymmetric addition to highly reactive imines generated in situ from α‐amidosulfones (see scheme; Pg=protecting group). The synthetic utility of the products was demonstrated by their straightforward transformation into a range of β‐amino acid derivatives.