Electrochemical oxidative radical cascade cyclization of olefinic amides and thiophenols towards the synthesis of sulfurated benzoxazines, oxazolines and iminoisobenzofurans
containing N and O are important structures in pharmaceuticals, agrochemicals and functional molecules. The synthesis of these compounds usually requires complex substrates and harsh reaction conditions. Herein, we introduce a mild and efficient electrochemical oxidative strategy to construct benzoxazines, oxazolines and iminoisobenzofurans without the requirement of a transition-metal catalyst and an
含 N 和 O 的杂环是药物、农用化学品和功能分子中的重要结构。这些化合物的合成通常需要复杂的底物和苛刻的反应条件。在此,我们引入了一种温和有效的电化学氧化策略来构建苯并恶嗪、恶唑啉和亚氨基异苯并呋喃,而无需过渡金属催化剂和外部氧化剂。在一个简单的未分开的细胞中,各种烯酰胺和苯硫酚/二硒化物反应生成 69 个硫醇化和硒化杂环的例子,产率高达 83%。此外,这种自由基级联反应为一步构建 C-S/C-Se 和 C-O 键提供了一种简便的方法。
Organoiodine-Catalyzed Enantioselective Intramolecular Oxyaminations of Alkenes with N-(Fluorosulfonyl)carbamate
作者:Takuya Hashimoto、Chisato Wata
DOI:10.1055/s-0037-1610768
日期:2021.8
Organoiodine-catalyzed enantioselective intramolecular oxyaminations were realized by the use of benzyl N-(fluorosulfonyl)carbamate as the exogenous nitrogen source. The method allows access to enantioenriched lactones and oxazolines, starting from γ,δ- and δ,ε-unsaturated esters and N-allyl amides, respectively.
haloheterocyclization of N-alkenylamides using bulk and common chemicals such as 1,2-dihaloethanes as halogenating reagents are less studied. Herein, we have developed an electrochemical intramolecular haloheterocyclization of N-alkenylamides to prepare 2-oxazolines, 2-thiazolines, 1,3-oxazines and isoxazolines using readily available 1,2-dihaloethanes as halogenating reagents. This protocol is a convergent
Metal-Free Oxidative Functionalization of C(sp<sup>3</sup>)–H Bond Adjacent to Oxygen and Radical Addition to Olefins
作者:Wei Zhou、Ping Qian、Jincan Zhao、Hong Fang、Jianlin Han、Yi Pan
DOI:10.1021/acs.orglett.5b00088
日期:2015.3.6
A DTBP-promoted oxidative functionalization of a C(sp3)–Hbond adjacent to oxygen and intermolecular radical addition to olefins without use of any metal catalyst or photoredox catalysis is reported. The reaction has a wide scope of olefin, alcohol, and cycloether substrates, which provides an easy way for direct preparation of α,ω-amino alcohols.
the simultaneous incorporation of a boron entity and an sp-fragment across the double bond. The products contain boryl, alkynyl, and carbonyl functional groups with orthogonal synthetic reactivities, offering three handles for further derivatization to access valuable intermediates. The utility of this ligand-enabled asymmetric protocol has been highlighted through the late-stage decoration of drug-relevant