Asymmetric catalytic [3 + 3]-cycloaddition of γ-hydroxy-α,β-unsaturated ketones with azaoxyallyl cations

Diastereo- and Enantioselective (3 + 2) Cycloaddition of a New Aza-π-Allylpalladium Zwitterionic Intermediate

“…Dipolar cycloadditions of the crucial C(CO)N synthon’s synthetic equivalents have therefore attracted considerable interest. While the reactivity of α-haloamides has been widely documented, only two enantioselective dipolar cycloadditions have been reported and rely on the activation of the electrophilic cycloaddition partner by a squaramide organocatalyst . The group of Hamada exploited the dipolar properties of acrylamides to design an enantioselective (3 + 2) cycloaddition based on a chiral iminium activation method .…”

Chemodivergent 1,3-Dipolar Cycloadditions of C,N-Cyclic Azomethine Imines with γ-Sulfonamido-α,β-Unsaturated Ketones to Synthesize Tricyclic Dinitrogen-Fused Heterocycles

“…Subsequently, in 2014, Wang et al and Fraile et al independently developed prolinol silyl ether organocatalyzed 1,3-dipolar cycloadditions of C , N -cyclic azomethine imines with α,β-unsaturated aldehydes (Scheme (2)). , In 2019, Kang et al developed rhodium complex-catalyzed [3 + 2]-cycloadditions of C , N -cyclic azomethine imines with α,β-unsaturated 2-acyl imidazoles . As a part of our continued interest in cycloaddition, in this study, we developed a novel base-catalyzed [3 + 2]-cycloaddition of C , N -cyclic azomethine imines with α,β-unsaturated ketones. N -benzoyl-protected C , N -cyclic azomethine imine substrates afforded tetrahydroisoquinolines (Scheme (3)), whereas N -tosyl-protected C , N -cyclic azomethine imines furnished tetrahydropyrazolo [5,1- a ]­isoquinolines (Scheme (4)).…”

Catalytic enantioselective [3+2] and [4+2]-annulation of cyclic N-sulfonyl ketimines with γ- or δ-hydroxy-α,β-unsaturated ketones

“…Herein, we report the asymmetric [3+2]- and [4+2]-annulation of cyclic N -sulfonyl ketimines with γ- or δ-hydroxy-α,β-unsaturated ketones, yielding enantioenriched N,O-containing polycyclic benzosultam derivatives featuring chiral quaternary centers. 10…”