Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India.
Chem Asian J. 2023 Feb 14;18(4):e202201114. doi: 10.1002/asia.202201114. Epub 2023 Jan 16.
A powerful CuCl-catalyzed sequential one-pot reaction of aryl methyl ketoxime acetates with cyclic N-sulfonyl imines followed by elimination in the presence of base is reported. This hydrazine-free method conveniently makes C-C and N-N bonds via a radical cleavage of the N-O bond, delivering a special class of C3-hydroxyarylated pyrazoles in good yields. Surprisingly, while employing CuI as a catalyst instead of CuCl, the reaction proceeds through a non-radical pathway which embodies a new tactic for the high-yielding access to value-added conjugated N-unsubstituted ketimines. Moreover, additive-free approach to sulfamidate-fused-pyrazoles was achieved by successfully catalyzing addition and oxidative N-N bond-making reactions by CuI and CuCl, respectively. Significantly, our novel technique could convert the prepared ketimines into the pharmacologically recognized 6H-benzo[c]chromene frameworks.
一种强有力的 CuCl 催化的芳基甲基酮肟乙酸酯与环状 N-磺酰亚胺的顺序一锅反应，随后在碱的存在下消除，本文对此进行了报道。这种不含肼的方法通过 N-O 键的自由基断裂方便地形成了 C-C 和 N-N 键，以良好的收率得到了一类特殊的 C3-羟基芳基吡唑。令人惊讶的是，虽然采用 CuI 而不是 CuCl 作为催化剂，但反应通过非自由基途径进行，为高产率获得附加值的共轭 N-未取代亚胺提供了一种新策略。此外，通过 CuI 和 CuCl 分别成功催化加成和氧化 N-N 键形成反应，实现了无添加剂的磺酰胺稠合吡唑。值得注意的是，我们的新技术可以将制备的亚胺转化为药理学上公认的 6H-苯并[c]色烯骨架。
