Iron‐Catalyzed One‐Step Synthesis of Isothiazolone/1,2‐Selenazolone Derivatives via [3+1+1] Annulation of Cyclopropenones, Anilines, and Elemental Chalcogens
作者:Hongchen Wang、Rulong Yan
DOI:10.1002/adsc.202101175
日期:2022.2.15
Described herein is the one-step synthesis of isothiazolone/1,2-selenazolone derivatives via [3+1+1] cycloaddition of cyclopropenone derivatives, anilines, and elemental chalcogens. The cascade reaction involves the C−S, C−N, and N−S bond formation along with the cleavage of C−C bond. Both anilines and cyclopropenones are tolerated and give the corresponding products in 28–73% yields.
Lanthanide Silylamide-Catalyzed Synthesis of Pyrano[2,3-<i>b</i>]indol-2-ones
作者:Qifa Chen、Yue Teng、Fan Xu
DOI:10.1021/acs.orglett.1c01506
日期:2021.6.18
A lanthanide silylamide-catalyzed tandem reaction of isatins, diethyl phosphite, and 2,3-diarylcyclopropenones has been developed. A series of pyrano[2,3-b]indol-2-ones were synthesized in high yields. The cooperation of the Lewis acidity of the lanthanide center and the Bronsted basicity of the N(SiMe3)2 anion may be the key factor affecting the catalytic activity of lanthanide amides.
已经开发了镧系元素甲硅烷基酰胺催化的靛红、亚磷酸二乙酯和 2,3-二芳基环丙烯酮的串联反应。以高产率合成了一系列吡喃并[2,3 - b ]indol-2-ones。镧系元素中心的路易斯酸度和N(SiMe 3 ) 2阴离子的布朗斯台德碱度的协同作用可能是影响镧系酰胺催化活性的关键因素。
Development of a Catalytic Platform for Nucleophilic Substitution: Cyclopropenone-Catalyzed Chlorodehydration of Alcohols
作者:Christine M. Vanos、Tristan H. Lambert
DOI:10.1002/anie.201104638
日期:2011.12.16
Cyclopropenone makes the switch: 2,3‐Bis‐(p‐methoxyphenyl)cyclopropenone is a highly efficient catalyst for the chlorodehydration of 20 diverse alcohol substrates (see scheme; X=Cl). With oxalyl chloride as catalytic activator, this nucleophilicsubstitution proceeded through cyclopropenium‐activated intermediates and resulted in complete stereochemical inversion in substrates with chiral centers.
环丙烯酮起到了作用:2,3-双(对甲氧基苯基)环丙烯酮是一种高效的催化剂,可对20种不同的醇底物进行氯脱水(参见方案; X = Cl)。用草酰氯作为催化活化剂,这种亲核取代过程通过环丙烯活化的中间体进行,并导致具有手性中心的底物完全立体化学转化。
Organocatalyzed [3 + 2] Annulation of Cyclopropenones and β-Ketoesters: An Approach to Substituted Butenolides with a Quaternary Center
作者:Xuanyi Li、Chunhua Han、Hequan Yao、Aijun Lin
DOI:10.1021/acs.orglett.6b03737
日期:2017.2.17
An unprecedented organocatalyzed [3 + 2] annulation of cyclopropenones and β-ketoesters has been developed. This reaction provides a direct approach to highly substitutedbutenolides with a quaternary center in moderate to good yields. The preliminary mechanism study verified that the enol intermediate is crucial to the reaction outcome and the intermolecular esterification and intramolecular Michael
reported that combines a cycloaddition reaction with a regioselective strain‐release process to afford diverse heterocyclic frameworks through bifunctional catalysis. The cooperation of hydrogen‐bonding network activation and a regiodivergent strain‐assisted effect is the key to promoting this complex chemical transformation, leading to the generation of two different ring systems in high yields with excellent