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。
Fully Substituted Conjugate Benzofuran Core: Multiyne Cascade Coupling and Oxidation of Cyclopropenone
作者:Liangliang Yao、Qiong Hu、Li Bao、Wenjing Zhu、Yimin Hu
DOI:10.1021/acs.orglett.1c01304
日期:2021.7.2
multiyne cascade coupling has been developed. This chemistry provides a novel, simple, and efficient approach to synthesize fullysubstituted conjugate benzofuran derivatives from simple substrates under mild conditions. The density functional theory (DFT) calculations reveal that the unique homolytic cleavages of cyclopropenone and molecular oxygen are crucial to the success of this reaction.
saturated oxygenheterocycles, providing an efficient method for the synthesis of 3-haloacrylates. The ring-opening reaction enables the construction of two C–X (X = Cl, Br, or I) bonds and a C–O bond as well as the cleavage of two C–O bonds and a C–C bond in a single step. This protocol is highly atomeconomical, has an excellent substrate scope, and exhibits the ability for gram-scale reaction.
Indolizine 1-sulfonates as potent inhibitors of 15-lipoxygenase from soybeans
作者:Solomon Teklu、Lise-Lotte Gundersen、Tove Larsen、Karl E. Malterud、Frode Rise
DOI:10.1016/j.bmc.2005.02.056
日期:2005.5
trapping of the intermediate 1-indolizinol with a sulfonylhalide, and examined as inhibitors of 15-lipoxygenase (15-LO). The compounds display IC(50) values between 15 and 42 microM; all are more active than the well-known 15-LO inhibitor quercetin (IC(50) 51 microM). A wide variety of substituents are well tolerated. The enzyme inhibition was not affected by preincubation or the presence of a detergent