Synthesis of Tropinones by Cyclization of 1,3-Bis-Silyl Enol Ethers with ­Iminium Triflates

Abstract

Tropinone derivatives were prepared by cyclization of 1,3-bis-silyl enol ethers with iminium salts.

Synthesis of Bridged and Nonbridged N‐Heterocycles by Cyclocondensation of Bis(silyl enol ethers) with Iminium Salts

“…The Me 3 SiOTf‐mediated cyclization of 1,3‐bis(silyl enol ethers) 18 with 2,5‐dimethoxypyrrolidine 24 afforded the tropinones 25 (Scheme ) 29. The tropinone substructure is present in pharmacologically relevant tropane alkaloids 30…”

Synthesis of 7,8-Benzo-3-hydroxy-9-azabicyclo[3.3.1]non-3-enes by Cyclocondensation of 1,3-Bis-Silyl Enol Ethers with Isoquinolines

“…9 We have recently reported cyclocondensations of 1,3-bis-silyl enol ethers 10,11 with benzopyrylium triflates 12 and 2,5-dimethoxypyrrolidines. 13 Herein, we wish to report what are, to the best of our knowledge, the first cyclocondensations of 1,3-bis-silyl enol ethers with isoquinolinium salts. These reactions allow a new and convenient synthesis of functionalized 7,8-benzo-3-hydroxy-9-azabicyclo[3.3.1]non-3-enes.…”