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Thermal Electrocyclic Reactions: Stereochemistry

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Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

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Published on: December 16, 2022

Enantioselective Contrathermodynamic Olefin Isomerization.

Bianca L Imbriaco¹, Sumin Lee¹, Eve Yuanwei Xu¹

¹Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.

Journal of the American Chemical Society

|May 1, 2026

Summary

This summary is machine-generated.

This study introduces a novel light-driven method for enantioselective olefin isomerization. The process utilizes excited-state electron transfer and a chiral chromium catalyst to produce terminal olefins with high selectivity.

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Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators

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Area of Science:

Organic Chemistry
Photochemistry
Catalysis

Background:

Contrathermodynamic positional isomerization of olefins is challenging.
Enantioselective synthesis of olefins is crucial for pharmaceuticals and materials.

Purpose of the Study:

To develop a light-driven method for enantioselective contrathermodynamic olefin isomerization.
To achieve high regio- and enantioselectivity in olefin synthesis.

Main Methods:

Excited-state electron transfer initiated reaction.
Sequential oxidation and deprotonation of enol ethers.
Utilizing a chiral chromium(II) cocatalyst with a bioxazoline (BiOX) ligand.
Regio- and enantioselective protodemetalation using methanol.

Main Results:

Successful enantioselective contrathermodynamic positional isomerization of olefins.
Generation of an allylic radical intermediate captured by a chiral chromium complex.
Production of terminal olefin products with up to 95:5 er.
Identification of enantiodetermining protodemetalation and two primary kinetic isotope effects (KIEs).

Conclusions:

The developed method offers a novel pathway for enantioselective olefin synthesis.
The findings provide insights into the mechanism of enantioselective catalysis involving radical intermediates.
This work expands the toolkit for asymmetric synthesis using photochemistry.