Comparison of Substituting Ability of Nitronate versus Enolate for Direct Substitution of a Nitro Group
作者:Yusuke Mukaijo、Soichi Yokoyama、Nagatoshi Nishiwaki
DOI:10.3390/molecules25092048
日期:——
methylene compound such as nitroacetate, 1,3-dicarbonyl compound, or α-nitroketone, and the following ring closure afforded functionalized heterocyclic frameworks. The reaction of cinnamate with nitroacetate occurs via nucleophilic substitution of a nitro group by the O-attack of the nitronate, which results in isoxazoline N-oxide. This protocol was applicable to 1,3-dicarbonyl compounds to afford
α-硝基肉桂酸酯与活性亚甲基化合物如硝基乙酸酯、1,3-二羰基化合物或 α-硝基酮进行共轭加成,随后的环闭合得到功能化的杂环骨架。肉桂酸酯与硝基乙酸酯的反应是通过硝基的 O-攻击对硝基进行亲核取代而发生的,这会产生异恶唑啉 N-氧化物。该协议适用于 1,3-二羰基化合物,以提供二氢呋喃衍生物,包括由烯醇的 O-攻击引起的硝基的直接取代衍生的那些衍生物。发现羰基部分上的吸电子基团降低了反应性。当以α-硝基酮为底物时,可能形成三种产物;其中,仅鉴定了异恶唑啉 N-氧化物。