Copper-catalyzed [3+3] annulation of ketones with oxime acetates for the synthesis of pyridines

Abstract

We have successfully developed a practical Cu-catalyzed formal [3+3] annulation of ketones with oxime acetates, providing an efficient approach to valuable polysubstituted pyridines in moderate to good yields.

Recent Advances in Synthetic Routes to Azacycles

“…Several studies have succeeded in synthesizing or functionalizing azacycle compounds. In addition, several methods of synthesis for aromatic azacycles have been reported [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ]. However, these methods still have several drawbacks such as being time-consuming, requiring a high temperature, expensive additives, and/or organic solvents, and/or having low chemoselectivity properties [ 61 , 62 , 63 ].…”

Iron-Catalyzed Oxidative C(sp3)–C(sp3) Radical Coupling Reaction between Thiohydantoins and O-Acetyloximes for the Synthesis of 1,3-Dibenzyl-3,4-dihydropyrrolo[2,3-d]imidazole-2(1H)-thione Derivatives

“…[4][5][6][7] They are a major source of iminyl radicals through N-O bond cleavage, which is readily promoted by single-electron transfer (SET) with metals. 8,9 Iminyl radicals exist in equilibrium with C-centered radicals that undergo chemo-and regioselective radical-radical couplings with a group of radical substrates. Reactions in which nitrogen intramolecularly attacks an electrophilic site, result, after condensation, in the formation of an annelated nitrogen heterocycle (Scheme 1a).…”