Asymmetric C(sp(2) )-H activation
Joanna Wencel-Delord1, Françoise Colobert
1Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, F-67087 Strasbourg (France), 25, rue Rue Becquerel, 67087 Strasbourg (France).
Asymmetric C-H bond activation, especially for C(sp2)-H bonds, is a rapidly growing field. This study highlights direct, stereoselective methods for creating complex molecules efficiently.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Chemistry
Background:
- Asymmetric C-H bond activation has transitioned from a niche topic to a rapidly growing area of research.
- Significant progress has been made in direct, stereoselective transformations involving C(sp2)-H bonds.
Purpose of the Study:
- To present a comprehensive overview of various asymmetric C(sp2)-H bond activation reactions.
- To emphasize the stereo-discriminating mechanisms within these reactions.
- To illustrate the diverse and valuable molecular scaffolds constructible through these strategies.
Main Methods:
- Review of recent literature on asymmetric C(sp2)-H bond activation.
- Categorization of reactions based on stereo-discrimination principles.
- Analysis of the scope and limitations of different synthetic strategies.
Main Results:
- Demonstration of diverse asymmetric C(sp2)-H activation methodologies.
- Highlighting key catalytic systems and their stereochemical outcomes.
- Showcasing the efficient synthesis of complex molecular architectures.
Conclusions:
- Asymmetric C(sp2)-H bond activation offers powerful and efficient routes to stereochemically defined molecules.
- These strategies enable rapid access to valuable scaffolds relevant to medicinal chemistry and materials science.
- Continued development in this field promises further advancements in synthetic efficiency and molecular complexity.
Related Concept Videos
Cycloaddition Reactions: MO Requirements for Thermal Activation
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Electrophilic Addition to Alkynes: Halogenation
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
Hybridization of Atomic Orbitals I


