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Advanced Free Radical Reactions for Organic Synthesis

Beschreibung

Free radical reactions have become increasingly important and a very attractive tool in organic synthesis in the last two decades, due to their powerful, selective, specific, and mild reaction abilities. Advanced Free Radical Reactions for Organic Synthesis reviews information on all types of practical radical reactions, e.g. cyclizations, additions, hydrogen-atom abstractions, decarboxylation reactions. The book usefully provides experimental details for the most important reactions as well as numerous references to the original literature. By covering both the fundamentals and synthetic applications it is therefore suitable for both new and experienced researchers, chemists, biochemists, natural product chemists and graduate students. This title is the definitive guide to radical chemistry for all scientists.

Besprechung

Reaktionen mit Radikalen haben noch immer den Nimbus, sie wären schlecht beherrschbar und führten zu einer Vielzahl von Nebenprodukten. Dieses Vorurteil widerlegt Hideo Togo in seinem bemerkenswerten Buch. "Advanced Free Radical Reactions for Organic Synthesis" enthält viele wissenswerte Details zu den Eigenschaften von Radikalen und erklärt die wichtigen Prinzipien, welche helfen, die Selektivität von radikalischen Reaktionen vorherzusagen (zum Beispiel die Baldwin-Regeln bei Ringschluss-Reaktion). Die ersten Kapitel sind daher ein sehr guter Leitfaden für alle - insbesondere fortgeschrittene Studenten - welche sich mit Radikalchemie befassen wollen.

Die nachfolgenden Kapitel beleuchten konkrete Umsetzungen aus der aktuellen Literatur. Der Autor hat eine Vielzahl interessanter Literaturstellen zusammengefasst, was einen sehr eindrücklichen Querschnitt aller Möglichkeiten bietet und eine grosse Bandbreite an möglichen, chemischen Umsetzungen abdeckt. Von grossem Nutzen sind die unzähligen, eingestreuten Synthese-Vorschriften. Auch wenn sie kurz gehalten sind, ermöglichen sie doch den schnellen Einstieg zu eigenen experimentellen Erfahrungen.

Dem Autor ist es gelungen, viele Facetten dieser überaus interessanten Chemie, in einer ansprechenden Weise zu präsentieren. Wer sich mit Radikalchemie befassen will, sollte aus diesem Grund einen Blick in "Advanced Free Radical Reactions for Organic Synthesis" werfen.

Inhalt

What are Free Radicals?
General Aspects of Free Radicals. Aspects of free radicals. Types of free radicals. Reaction style of radicals. Orientation in radical additions. Reactivity in radical additions. Reaction patterns of radicals. Generation of radicals. Familiar and Close Radicals in Our Lives. Stable Free Radicals. Physical and Chemical Characteristics of Free Radicals. Orbital interactions between radicals and olefins. Baldwin's rule. Rate constants in radical reactions.

2. Functional Group Conversion
Radical Coupling Reactions. Radical Reduction. Conversion to Hydroxy Group and Other Functional Groups.

3. Intramolecular Radical Cyclizations
Cyclization to Small-Sized Rings. Cyclization onto olefinic group and acetylenic group by sp³ carbon-centered radicals. Cyclization onto Olefinic Group and Aromatic Group by sp² Carbon-Centered Radicals. Generation of sp carbon-centered radicals. Cyclization onto carbonyl group by sp³ or sp² carbon-centered radicals and other related cyclizations. Cyclization to Medium-Sized and Large-Sized Rings. Ring Expansions. Cyclization to Spiro Skeleton. Tandem Cyclization to Polycyclic Rings.

4. Intermolecular Radical Addition Reactions
Addition to Olefins. Reductive conditions. Oxidative conditions. Photochemical conditions. Addition-elimination reactions. Allylation Reactions. Addition-Cyclization Reactions. Reactions with Carbon Monoxide. Addition to Acetylenes.

5. Alkylation of Aromatics
Oxidative Conditions. Non-Oxidative Conditions. Photochemical Conditions. Others.

6. Intramolecular Hydrogen-Atom Abstraction
Hydrogen-atom Abstraction by Oxygen-Centered Radicals: Barton Reaction. Hydrogen-atom Abstraction by Nitrogen-Centered Radicals: Hofmann-Loffler-Freytag Reaction. Hydrogen-atom Abstraction by Carbon-Centered Radicals.

7. Synthetic Uses of Free Radicals for Nucleosides and Sugars: Barton-McCombie Reaction

8. Barton Decarboxylation Reaction with N-hydroxy-2-thiopyridone
Reduction. Conversion to Halides. Conversion to Chalcogenides. Conversion to Other Functional Groups. Carbon-Carbon Bond Formation. Intramolecular radical cyclization. Intermolecular coupling reaction. Intermolecular addition reaction. Alkylation of aromatics. Others.

9. Free Radical Reactions with Metal Hydrides

10. Stereochemistry in Free Radical Reactions
Reduction. Carbon-Carbon Bond Formation.

11. Free Radicals Related to Biology
Vitamin B12. Ene-diyne Reactions: Bergman Cyclization. Radical 1,2-Acyloxy Transfer.

12. Free Radicals for Green Chemistry
Design of Free Radical Precursors. Application of Free Radicals to Environmentally Benign Synthesis.