描述了一种温和且操作简单的铜催化乙烯基有氧氧化 β,γ-和 α,β-不饱和酯。该方法具有收率好、底物范围广、化学选择性和区域选择性好、官能团耐受性好等特点。该方法还能够氧化β,γ-和α,β-不饱和醛、酮、酰胺、腈和砜。此外,本催化体系适用于双乙烯基和三乙烯基氧化。发现四甲基胍 (TMG) 作为碱的作用至关重要,但我们也推测它可以作为三氟甲磺酸铜 (II) 的配体来生产活性铜 (II) 催化剂。进行的机械实验表明,通过烯丙基铜 (II) 物质存在一个合理的反应途径。最后,
Synthesis of Carbazoles by a Diverted Bischler–Napieralski Cascade Reaction
作者:Matteo Faltracco、Said Ortega-Rosales、Elwin Janssen、Răzvan C. Cioc、Christophe M. L. Vande Velde、Eelco Ruijter
DOI:10.1021/acs.orglett.1c00785
日期:2021.4.16
An unforeseen twist in a seemingly trivial Bischler–Napieralskireaction led to the selective formation of an unexpected carbazole product. The reaction proved to be general, providing access to a range of diversely substituted carbazoles from readily available substrates. Judicious variation of substituents revealed a complex cascade mechanism comprising no less than 10 elementary steps, that could
ZnI<sub>2</sub>/Zn(OTf)<sub>2</sub>-TsOH: a versatile combined-acid system for catalytic intramolecular hydrofunctionalization and polyene cyclization
作者:Ting-Hung Chou、Bo-Hung Yu、Rong-Jie Chein
DOI:10.1039/c9cc07242j
日期:——
combined-acid system using a zinc(II) salt [ZnI2 or Zn(OTf)2] and p-toluene sulfonic acid (TsOH) was investigated for catalytic cationic cyclizations, including intramolecular hydrocarboxylation, hydroalkoxylation, hydroamination, hydroamidation, hydroarylation and polyenecyclizations. This reaction provides easy access to five- and six-membered O- and N-containing saturated heterocyclic compounds, tetrahydronaphthalene
Green Organocatalytic Synthesis of Isoxazolines via a One-Pot Oxidation of Allyloximes
作者:Ierasia Triandafillidi、Christoforos G. Kokotos
DOI:10.1021/acs.orglett.6b03380
日期:2017.1.6
A green, sustainable, organocatalytic, and efficient synthesis of isoxazolines from allyloximes was developed. A 2,2,2-trifluoroacetophenone-catalyzed oxidation of allyloximes, utilizing H2O2 as the green oxidant, was taken advantage of in order to introduce a cheap and environmentally friendly protocol for the synthesis of substituted isoxazolines. A variety of substitution patterns, both aromatic
从烯丙基肟开发了一种绿色,可持续,有机催化和高效的异恶唑啉合成方法。利用H 2 O 2作为绿色氧化剂,利用2,2,2-三氟苯乙酮催化的烯丙基肟的氧化反应,以引入廉价且环境友好的方法合成取代的异恶唑啉。芳香族和脂肪族部分的各种取代方式都具有良好的耐受性,从而导致异恶唑啉的产率中等至优异。
A facile synthesis of γ-butenolides via cyclization of 3-alkenoic acids with dimethyl sulfoxide and oxalyl bromide
Abstract The combination of dimethylsulfoxide and oxalyl bromide was used to accomplish the cyclization of 3-alkenoic acids with the aid of a base to afford γ-butenolides, in which bromodimethylsulfonium salt generated in situ was proposed to serve as a Br+ source. GRAPHICAL ABSTRACT
Highly Regio- and Diastereoselective Synthesis of CF<sub>3</sub>-Substituted Lactones <i>via</i> Photoredox-Catalyzed Carbolactonization of Alkenoic Acids
use of a Ru photocatalyst and Umemoto’s reagent as a CF3 source is key in the present carbolactonization. This is the first example of a highly endo- and diastereoselectivesynthesis of CF3-substituted five-, six-, and seven-membered ring lactones from internal alkenoic acids.