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Lecture

Aldolization: Zimmermann-Traxler vs Evans Auxiliary

In course

CH-335: Asymmetric synthesis and retrosynthesis

The first part of the course presents the classical methods of asymmetric synthesis. The second part of the course introduces retrosynthesis strategies based on the disconnection approach. ...

Description

This lecture covers the concept of aldolization, comparing the Zimmermann-Traxler model with the Evans auxiliary. It discusses the Aldol d'Evans and its variations, as well as the Aldol de Patterson. Additionally, it introduces the chemistry of Imines/Enamines, focusing on stereospecific reactions and the coordination of enolates with metals.

Instructors (2)

Stefano Nicolai

Sandrine Gerber

Sandrine Gerber studied chemistry at the "Ecole Nationale Supérieure de Chimie de Paris" in France, where she obtained a diploma of chemical engineer in 1993. The same year she obtained a DEA (Master degree) of organic chemistry at the University Pierre et Marie Curie (Paris VI, France). From 1993 to 1996 she did a PhD in organic chemistry under the supervision of Prof. Jean-Pierre Genêt at the Ecole Nationale Supérieure de Chimie de Paris. In 1996, she moved to University of Lausanne for a post-doctoral stay under the supervision of Prof. Pierre Vogel. In 1998, she was appointed Maître-Assistante at the Institute of Organic Chemistry in the University of Lausanne. In 2003, she obtained the habilitation to direct research from the University Pierre et Marie Curie (Paris VI, France). The same year, she was appointed scientific adjunct at the EPFL and senior scientist (Maître d'Enseignement et de Recherche) in 2006. In December 2014, she was promoted to titular professor. Since September 2007, Sandrine Gerber is deputy to the director of the Institute of Chemical Sciences and Engineering (ISIC). She is also member of the Board of Directors of the Swiss Chemical Society. Since 2007, Sandrine Gerber is part-time lecturer at the university of Fribourg. She was awarded the Prize Eugene Schueller in 1997, the Prize Dufour for prospective organic chemistry in 2005 and the Werner Prize 2010. She also received a special mention in recognition of exceptional quality of pedagogic competencies in the teaching of basic sciences, given by the Direction of the School of Biology and Medicine from the University of Lausanne, in 2013. In October 2018, she will receive the Prize for Excellence in Teaching from the section of Chemistry and Chemical Engineering.

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Related concepts (18)

Aldol reaction

The aldol reaction (aldol addition) is a reaction that combines two carbonyl compounds (aldehydes or ketones) to form a new β-hydroxy carbonyl compound. These products are known as aldols, from the aldehyde + alcohol, a structural motif seen in many of the products. The use of aldehyde in the name comes from its discovery history, where aldehydes were first used in the reaction and not ketones. Aldol structural units are found in many important molecules, whether naturally occurring or synthetic.

Chiral auxiliary

In stereochemistry, a chiral auxiliary is a stereogenic group or unit that is temporarily incorporated into an organic compound in order to control the stereochemical outcome of the synthesis. The chirality present in the auxiliary can bias the stereoselectivity of one or more subsequent reactions. The auxiliary can then be typically recovered for future use. Most biological molecules and pharmaceutical targets exist as one of two possible enantiomers; consequently, chemical syntheses of natural products and pharmaceutical agents are frequently designed to obtain the target in enantiomerically pure form.

Coordination complex

A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals (elements like titanium that belong to the periodic table's d-block), are coordination complexes. Coordination complexes are so pervasive that their structures and reactions are described in many ways, sometimes confusingly.

Imine

In organic chemistry, an imine (ᵻˈmiːn or ˈɪmɪn) is a functional group or organic compound containing a carbon–nitrogen double bond (). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions. For ketimines and aldimines, respectively, the five core atoms (C2C=NX and C(H)C=NX, X = H or C) are coplanar.

Coordination sphere

In coordination chemistry, the first coordination sphere refers to the array of molecules and ions (the ligands) directly attached to the central metal atom. The second coordination sphere consists of molecules and ions that attached in various ways to the first coordination sphere. The first coordination sphere refers to the molecules that are attached directly to the metal. The interactions between the first and second coordination spheres usually involve hydrogen-bonding. For charged complexes, ion pairing is important.

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Alkylation and Aldol Reaction

Covers the alkylation of enolates and the aldolisation reaction in organic synthesis.

Catalytic Asymmetric Reactions

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Catalytic Asymmetric Reactions in Organic Chemistry