10.1021/jo801308j.s001 Edouard Godineau Edouard Godineau Kurt Schenk Kurt Schenk Yannick Landais Yannick Landais Synthesis of Fused Piperidinones through a Radical-Ionic Cascade American Chemical Society 2008 lactamize aldoxime function ketoxime enoxime chiral allylsilanes High levels nucleophilic amidoborane initiator Et 3B species cyclopentane cyclization recombined stereochemistry Azabicyclo stereoinduction Synthesi ester fragments ability Fused Piperidinones iodoester Cascade stereocontrolled silicon group oxime moiety sterically stereogenic centers piperidinone cascade allylic position contrast alkoxyaminyl 2008-09-19 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Synthesis_of_Fused_Piperidinones_through_a_Radical_Ionic_Cascade/2912884 Azabicyclo[4.3.0]nonanes were assembled, from chiral allylsilanes possessing an oxime moiety, using a stereocontrolled formal [2 + 2 + 2] radical-ionic process. The cascade involves the addition of an α-iodoester to the less substituted end of the enoxime which is then followed by a 5-<i>exo</i>-<i>trig</i> cyclization onto the aldoxime function, producing an alkoxyaminyl radical species which finally lactamizes to afford the titled piperidinone. High levels of stereoinduction were observed, demonstrating the ability of a silicon group located at the allylic position to efficiently control the stereochemistry of the two newly created stereogenic centers. When the radical cascade was extended to ketoximes, the resulting sterically hindered alkoxyaminyl radical did not react further with the initiator Et<sub>3</sub>B to produce the expected nucleophilic amidoborane complex. In sharp contrast, this long-lived radical recombined with the initial α-stabilized ester radical to produce a cyclopentane incorporating two ester fragments.