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Regioselectivity and Stereochemistry of Hydroboration

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

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Catalyst-Controlled Stereoselective Barton-Kellogg Olefination.

Tanno A Schmidt¹, Christof Sparr¹

¹Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland.

Angewandte Chemie (International Ed. in English)

|August 20, 2021

Summary

This summary is machine-generated.

Researchers developed a new catalytic method for synthesizing overcrowded alkenes, enabling precise stereochemical control. This breakthrough facilitates the creation of complex molecules for advanced functional materials and applications.

Keywords:

Barton-Kellogg olefination higher-order stereogenicity overcrowded alkenes stereodivergent catalysis stereoselective catalysis

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

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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:

Organic Chemistry
Stereochemistry
Catalysis

Background:

Overcrowded alkenes possess unique stereochemical features crucial for applications in molecular switches and motors.
Previous synthesis of bistricyclic aromatic enes required stereospecific reactions and chiral auxiliaries, limiting broader application.

Purpose of the Study:

To develop a direct catalytic method for the stereoselective synthesis of overcrowded alkenes.
To achieve enantio- and diastereocontrol in the preparation of bistricyclic aromatic enes.

Main Methods:

Employed the Barton-Kellogg olefination catalyzed by Rh₂(S-PTAD)₄.
Coupled diazo compounds with thioketones followed by reduction.
Utilized distinct thiirane reductions to access all stereoisomers.

Main Results:

Achieved direct catalyst control for stereoselective Barton-Kellogg olefination.
Synthesized various bistricyclic aromatic enes with high enantiomeric ratios (up to 99:1).
Demonstrated complete stereodivergence, accessing all four anti-folded overcrowded alkene stereoisomers.

Conclusions:

This catalytic strategy enables the efficient and stereocontrolled synthesis of topologically unique overcrowded alkenes.
The developed method opens avenues for creating novel functional materials, catalysts, and bioactive compounds.