稳定的三环氨基过氧化物可以通过 β,δ'-三酮、H 2 O 2和 NH 基团源(如氨水或铵盐)的无催化剂三组分缩合选择性组装。这个过程是可扩展的并且可以产生克数量的三环杂环,在一个分子中包含过氧化物、氮和氧循环。令人惊讶的是,尽管有多种替代反应路线,通过过氧化物、半缩醛、单过氧缩醛和过氧半缩醛官能团的平衡,这种复杂的三环分子仍然可以选择性地形成!该反应由 H 2 O 2的“立体电子挫折”引发并将热力学和动力学控制元素与在热力学控制条件下演化的各种单环、双环和三环结构相结合,直到它们达到由逆α效应产生的动力学壁,即立体电子罚分过氧碳鎓离子和相关过渡态的形成。在这些条件下,在三个不同的杂环在无环前体框架上组装和融合的阶段,反应在达到最热力学稳定的产物之前停止。
Cerium(III) chloride heptahydrate in the presence of sodium iodide catalyses the Michael addition of 1,3-dicarbonyl compounds to α,β-unsaturated ketones and α,β-unsaturated aldehydes with extraordinary efficiency. The very mild conditions allow high chemoselectivity as shown by the absence of the typical side reactions, which can be observed in the conventional base-catalyzed processes. More interestingly
ZrCl<sub>4</sub>-Catalyzed Michael Reaction of 1,3-Dicarbonyls and Enones under Solvent-Free Conditions
作者:Ch. Reddy、G. Smitha、Sujatha Patnaik
DOI:10.1055/s-2005-861837
日期:——
ZrCl4 has been found to catalyze the conjugate addition of 1,3-dicarbonyl compounds with enones. The reaction does not require any solvent and proceeds smoothly at room temperature leading to the corresponding adduct in good yields.
Solvent free reaction under microwave irradiation: A new procedure for Eu+3 — Catalyzed Michael addition of 1,3-dicarbonyl compounds
作者:Annunziata Soriente、Aldo Spinella、Margherita De Rosa、Manuela Giordano、Arrigo Scettri
DOI:10.1016/s0040-4039(96)02294-0
日期:1997.1
CC bond formation via Michael addition is achieved in high yields and short times by employing catalytic amounts of EuCl3 in dry media undermicrowaveirradiation.
Silica gel-mediated catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to highly toxic methyl vinyl ketone without volatilization
作者:Kiyoshi Tanemura、Taoufik Rohand
DOI:10.1016/j.tetlet.2020.152142
日期:2020.7
Silica gel-mediated Michaeladdition of 1,3-dicarbonyl compounds to methyl vinylketone (MVK) and ethyl vinylketone (EVK) was carried out to give the corresponding adducts in quite excellent yields. The reactions could be carried out without any catalysts and solvents. In addition, highly toxic MVK and EVK could be employed without significant volatilization. Silica gel could be recycled five times
Hydrogen-Bond-Promoted C-C Bond-Forming Reaction: Catalyst-Free Michael Addition Reactions in Ethanol
作者:Seiji Shirakawa、Shoichi Shimizu
DOI:10.1055/s-2007-992377
日期:——
A practical protocol for catalyst-free Michael addition reactions in ethanol was developed. The reaction was promoted efficiently in alcohol without any additives, and the importance of hydrogen-bonding activation was suggested.