The Pauson-Khand reaction using alkynylboronic esters: solving a long-standing regioselectivity issue

Area of Science:

• Organic Chemistry
• Organometallic Chemistry

Background:

• The Pauson-Khand reaction is a vital tool for constructing cyclopentenones.
• Introducing functional groups regioselectively remains a synthetic challenge.

Purpose of the Study:

• To develop a novel intermolecular Pauson-Khand reaction.
• To enable the direct installation of boronic ester moieties into cyclopentenone structures.

Main Methods:

• Utilized internal alkynylboronic esters as substrates.
• Performed the intermolecular Pauson-Khand reaction under optimized conditions.

Main Results:

• Achieved the first successful intermolecular Pauson-Khand reaction with alkynylboronic esters.
• Demonstrated total regioselectivity and stereoselectivity in installing the boronic ester at the β-position.
• Successfully synthesized functionalized cyclopentenones.

Conclusions:

• This new methodology expands the scope of the Pauson-Khand reaction.
• Provides a powerful route for synthesizing complex molecules with precise stereochemical control.