Abstract:A Lewis base catalyzed chloroamidation of olefinic substrates was achieved using diphenyl selenide as the catalyst. The reaction conditions are mild and suitable for a wide range of substrates including those which are acid labile.
Catalytic aminohalogenation methods enable the regio- and stereoselective vicinal difunctionalization of alkynes, allenes and alkenes with amine and halogen moieties. A range of protocols and reaction mechanisms including organometallic, Lewis base, Lewis acid and Brønsted acid catalysis have been disclosed, enabling the regio- and stereoselective synthesis of halogen-functionalized acyclic amines and nitrogen heterocycles. Recent advances including aminofluorination and catalytic enantioselective aminohalogenation reactions are summarized in this review.
Catalytic aminohalogenation methods enable the regio- and stereoselective vicinal difunctionalization of alkynes, allenes and alkenes with amine and halogen moieties. A range of protocols and reaction mechanisms including organometallic, Lewis base, Lewis acid and Brønsted acid catalysis have been disclosed, enabling the regio- and stereoselective synthesis of halogen-functionalized acyclic amines and nitrogen heterocycles. Recent advances including aminofluorination and catalytic enantioselective aminohalogenation reactions are summarized in this review.
“…Hierbei wechselwirkt das Chalkogenzentrum senkrecht zur R‐Ch‐R′‐Ebene (siehe Abbildung ). Yeung und Mitarbeiter berichteten 2013 über eine Chloramidierung von Olefinen mit Nitrilen in Gegenwart der Organoselenide 12 , die als Lewis‐Basen fungierten und das Chlorierungsreagens aktivierten (Abbildung , links) . In einem aktuellen Beispiel veröffentlichten Zhao et al.…”
Section: Chalkogenbrücken In Der Organischen Synthese Und Der Nichtkounclassified
In den letzten Jahrzehnten haben sich “unübliche” nichtkovalente Wechselwirkungen wie Anion‐π oder Halogenbrücken in vielen Forschungsbereichen zu interessanten Alternativen zu den allgegenwärtigen Wasserstoffbrücken entwickelt. Dies trifft – zu einem etwas geringeren Grad – auch auf Chalkogenbrücken zu, die nichtkovalenten Wechselwirkungen Lewis‐acider Chalkogenzentren. Dieser Kurzaufsatz soll einen Überblick über den Einsatz von Chalkogenbrücken in der kondensierten Phase geben, mit einem Fokus auf den neuesten Entwicklungen bei der Anwendung intermolekularer Chalkogenbrücken in Lösung. Im Festkörper wurden Chalkogenbrücken zum Aufbau nanoskaliger Strukturen und für die Selbstorganisation ausgefeilter selbstkomplementärer Komplexe verwendet. Bis vor kurzem konzentrierten sich die Anwendungen in Lösung vor allem auf intramolekulare Wechselwirkungen, welche die Konformation von Intermediaten oder Reagentien stabilisierten. In den letzten Jahren wurden nun aber auch intermolekulare Chalkogenbrücken zunehmend in Lösung eingesetzt, besonders für Anionenerkennung und ‐transport sowie in der organischen Synthese und der Organokatalyse.
“…Literature reports on electrophilic haloamidation rely on the use of strong Lewis acids and acid‐sensitive substrates are less applicable. In this particular work, a Lewis base selenium‐catalyzed chloroamidation of olefinic substrates was achieved using diphenyl selenide as the catalyst and NCS as the halogen source (Scheme ) …”
Section: Monofunctional Lewis Base Catalystmentioning
Oxygen- and nitrogen-containing heterocyclic compounds are widely recognized as key components in many natural products and biologically relevant molecules, but often the problem comes down to methodologies in synthesizing them. Halocyclization of olefinic substrates is a promising strategy in the construction of O- and N-heterocyclic compounds, which further signifies the development of their asymmetric variants. Over the past years, our group has been devoted to this particular area of asymmetric electrophilic halocyclization with chalcogen-containing molecules as catalysts. In this account, the main focus is on the development of our novel chiral catalysts and applications derived from the reaction products.
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