Stereoselective synthesis of piperidinone and quinolinone systems via ring opening reactions using TiCl4/silyl reagents

Titanium(IV) chloride and silyl reagents mediated regio- and chemoselective ring opening reactions of oxa-bridged piperidinone ring systems were demonstrated. This methodology interestingly undergoes the stereoselective ring opening at the C–O bond of oxa-bridged piperidinone ring systems. Study of TiCl4 with hydride or non-hydride silyl reagents furnished the product with selectivity. This protocol is highly valuable to synthesize a range of stereoselective piperidinones, quinolinones ring systems.