Bristol Myers Squibb Lecture in Organic Chemistry: Enantioselective and Remote C–H Activation Reactions
Seminar | May 1 | 11 a.m.-12 p.m. | 120 Latimer Hall
The vast majority of directed CH activation reactions proceed via cyclometallation, in which a strongly coordinating functional group binds to the metal and facilitates cleavage of a proximate CH bond. These substrates driven reactions become problematic background reactions for developing enantioselective CH activation reactions. The use of weak coordination from substrates to direct metal insertion opens up possibility of designing ligand to significantly accelerate CH activation reactions. In ideal scenario of developing asymmetric CH activation reactions, the reaction should only proceed when chiral ligands are present. We have recently discovered a number of ligand scaffolds that can enable CH activation reactions of weakly coordinating substrates that are otherwise unreactive. Further development of chiral ligands have enabled the enantioselective CH activation reactions of methylene CH bonds for the first time. This effort has also led to the development of a biomimetic asymmetric transformation based on desymmetrization of an ubiquitous isopropyl group.
Inspired by how enzymes use directing effect to achieve remote selective CH activation, we have developed a number of site-selective remote CH activation reactions which are fundamentally distinct from the classic directed CH activation via cyclometalation processes. We focused our design on recognition of distance and geometry as the simplest parameters to achieve site selectivity, which has allowed us to activate CH bonds at remote sites that are previously not accessible. The combination of remote directing effect and ligand acceleration is analogous to flying a kite in the wind.
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Light refreshments will be served at 10:50 at The Coffee Lab