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Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

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Regioselectivity-switchable hydroarylation of styrenes.

Ke Gao¹, Naohiko Yoshikai

¹Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.

Journal of the American Chemical Society

|December 17, 2010

Summary

New cobalt catalysts enable regioselective hydroarylation of styrenes through C-H activation. This research details catalyst development and mechanistic insights into branched and linear product formation.

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A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Published on: February 16, 2020

Area of Science:

Organometallic Chemistry
Catalysis
Organic Synthesis

Background:

Hydroarylation reactions are crucial for synthesizing complex organic molecules.
Developing regioselective methods for C-H bond functionalization remains a significant challenge in catalysis.

Purpose of the Study:

To develop novel cobalt-based catalysts for the hydroarylation of styrenes.
To achieve high regioselectivity in forming both branched and linear addition products.
To elucidate the reaction mechanism through mechanistic studies.

Main Methods:

Synthesis and characterization of cobalt-phosphine and cobalt-carbene catalysts.
Hydroarylation reactions using various styrene substrates.
Deuterium-labeling experiments to probe reaction intermediates and rate-determining steps.

Main Results:

Cobalt-phosphine catalysts selectively produced linear hydroarylation products.
Cobalt-carbene catalysts selectively produced branched hydroarylation products.
Mechanistic studies indicated reversible C-H bond cleavage and olefin insertion, with reductive elimination being key.

Conclusions:

Chelation-assisted C-H bond activation provides a powerful strategy for regioselective hydroarylation.
The developed cobalt catalysts offer distinct pathways to linear and branched products.
Understanding the mechanism informs the design of future catalytic systems for C-H functionalization.