Controlling cyclization pathways in palladium(ii)-catalyzed intramolecular alkene hydro-functionalization via...

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Palladium catalysis is crucial for C-C and C-heteroatom bond formation.
• Intramolecular reactions offer efficient routes to cyclic compounds.
• Controlling regioselectivity and stereoselectivity in cyclizations remains a challenge.

Purpose of the Study:

• To develop novel palladium(II)-catalyzed intramolecular hydrofunctionalization reactions.
• To investigate the role of directing groups in controlling cyclization pathways.
• To elucidate the mechanistic basis for pathway selectivity.

Main Methods:

• Palladium(II)-catalyzed intramolecular reactions utilizing alkene substrates.
• Employing various carbon, nitrogen, and oxygen nucleophiles.
• Density Functional Theory (DFT) calculations to study reaction mechanisms.

Main Results:

• Successful synthesis of five- and six-membered carbo- and heterocycles.
• Demonstrated control over cyclization pathway and ring size by a proximal bidentate directing group.
• Observed pathway selection overriding Baldwin's rules and inherent preferences.

Conclusions:

• The developed methodology provides a versatile route to diverse cyclic structures.
• Proximal directing groups are powerful tools for controlling palladium-catalyzed cyclizations.
• DFT studies offer insights into the origins of observed selectivity.