S_N1-like Reactions of Bicyclic α-Amino Ethers with Sulfur, Nitrogen, and Carbon Nucleophiles. Synthesis of 1-Azabicyclo[3.2.2]nonanes Functionalized at Carbon C2 and C6 with Complete Stereocontrol

In the presence of nucleophiles, Lewis acid mediated cleavage of α-amino ethers derived from quincorine and quincoridine affords a variety of C2-substituted and C6-vinylated 1-azabicyclo[3.2.2]nonanes. These are enantiopure and are formed in S_N1-like reactions with complete stereocontrol. There is no leakage into 2-Nu en route to product 1-Nu or vice versa. Me₃SiCN provides new Strecker-type α-amino nitriles. In the presence of TTMPP−BF₃·OEt₂, the ketene acetal Me₂CC(OMe)OSiMe₃ delivers enantiopure bicyclic β-amino acid esters.