Taming Silylium Ions for Synthesis: N-Heterocycle Synthesis via Stereoselective C–C Bond FormationThis work was financially supported by the DOE (Basic Energy Sciences, DE-FG02-05ER15630)
Received: 08 May 2017
Accepted after revision: 28 June 2017
16 August 2017 (eFirst)
Published as part of the Cluster Silicon in Synthesis and Catalysis
Silylium ions (formally [R3Si]+) have long been the subject of investigations and significant debate in both theoretical and experimental chemistry, but few catalytic, synthetic applications have been reported due to the exceptionally high reactivity and Lewis acidity of these elusive species. Results to be discussed include the application of easily accessible silylium ion catalysts to the stereoselective synthesis of various N-heterocyclic pyrrolidine and piperidine scaffolds. The tested substrates are derived from the chiral pool and can be obtained in three high-yielding steps from amino alcohols; subsequent stereoselective silylium ion catalyzed Prins cyclization and trapping with R3Si–Nu nucleophiles (e.g., Nu = H, allyl, azide, and enol ethers) results in novel nitrogen-containing polycyclic scaffolds with potential medicinal chemistry applications.