Synthese du systeme cyclique de l'aza-triquinane lineaire par trois cyclisations radicalaires en cascade

Rapid Access to the Heterocyclic Core of the Calyciphylline A and Daphnicyclidin A-Type Daphniphyllum Alkaloids via Tandem Cyclization of a Neutral Aminyl Radical

“…Attempts to induce cyclization of ent -4 with BEt 3 and O 2 led to a 52% yield of N–Cl reduction products. 12 Use of neutral CuCl conditions 13 provided a low yield of the vinyl chloride. We were excited to find that reaction with AIBN and tributyltin hydride at 80 °C in toluene afforded 40–50% yields of tandem cyclization product ent -3 (Table 1).…”

Synthetic and Computational Study of Tin-Free Reductive Tandem Cyclizations of Neutral Aminyl Radicals

“…2 We were attracted to the potential utility of neutral aminyl radicals to construct these frameworks because radical cascades have well established reactivity with predictable bond construction outcomes. While amidyl, 3 iminyl, 4 and aminium 5 radicals are more reactive and tend to cyclize more efficiently 6,7 than the more stable neutral aminyl radicals, 8,9 the latter are strategically appealing because their cyclization reactions lead directly to aliphatic amine-containing products. 10 In this work, we demonstrate the utility of our recently reported 11 tin-free conditions for the cyclization of neutral aminyl radicals.…”

Triarylaminium Salt Induced Oxidative Cyclizations of Tertiary Amines. Convenient Access to 2-Substituted Pyrrolidinium Salts

“…The most widely applied methods are intramolecular N-alkylations, [3 + 2] cycloadditions, , or intramolecular additions to multiple bonds. Most notable for the last strategy are Li-, Pd- or lanthanoid-catalyzed 4c, cyclizations, intramolecular halo- or selenoaminations, , or cyclizations of aminyl radicals, generated from N -haloamines, N -sulfenylamines, or PTOC-carbamates …”

“…The most widely applied methods are intramolecular N-alkylations, 1 [3 + 2] cycloadditions, 1,2 or intramolecular additions to multiple bonds. Most notable for the last strategy are Li-, 3 Pd-4 or lanthanoid-catalyzed 4c,5 cyclizations, intramolecular halo-or selenoaminations, 1,6 or cyclizations of aminyl radicals, 7 generated from N-haloamines, 8 N-sulfenylamines, 9 or PTOC-carbamates. 10 However, almost all of these methods are applicable only to primary and secondary amine derivatives 11 and require usually the preparation of N-functionalized precursors.…”