Positional isomerization of N-allyl compounds with a practical low-valent cobalt catalyst system

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Developing efficient synthetic routes for enamides and N-alkenyl heterocycles is crucial in organic synthesis.
• Cobalt catalysis offers a promising avenue for novel transformations.
• Positional isomerization is a valuable tool for rearranging molecular structures.

Purpose of the Study:

• To report a practical and (E)-stereoselective synthesis of enamides and N-alkenyl heterocycles.
• To introduce a novel cobalt-catalyzed positional isomerization reaction.
• To demonstrate the applicability of this method to various N-allyl imides, sulfonamides, and nitrogen heterocycles.

Main Methods:

• Utilizing a cobalt catalyst with commercially available and bench-stable reagents.
• Performing positional isomerization of N-allyl imides, sulfonamides, and nitrogen heterocycles (indoles, carbazoles, pyrroles).
• Conducting mechanistic studies to elucidate the reaction pathway.

Main Results:

• Achieved (E)-stereoselective synthesis of enamides and N-alkenyl heterocycles.
• Demonstrated the first cobalt-catalyzed positional isomerization for N-allyl imides, sulfonamides, and nitrogen heterocycles.
• Identified a cobalt-hydride-type pathway through mechanistic investigations.

Conclusions:

• The reported method provides a practical and stereoselective route to valuable organic compounds.
• Cobalt catalysis is effective for positional isomerization, expanding synthetic capabilities.
• The mechanistic insights offer a foundation for further catalyst development and reaction optimization.