Switchable Regiodivergent Reductive Alkyl-Alkyl Coupling by Nickel Catalysis: Sorting Different Alkyl-Nickel...

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Site-selective functionalization of unactivated saturated alkyl chains is a significant challenge in organic synthesis.
• Developing methods for precise control over C-H bond activation and functionalization is crucial for accessing complex molecular architectures.

Purpose of the Study:

• To develop a ligand-controlled nickel-catalyzed method for site-selective and divergent alkyl-alkyl reductive coupling.
• To achieve chemo- and position-selective alkylation of unactivated C-H bonds in amines.
• To enable the synthesis of diverse branched aliphatic amine structures from simple starting materials.

Main Methods:

• Utilizing a ligand-controlled nickel catalyst for reductive coupling of two different alkyl halides.
• Employing reaction conditions that favor specific radical intermediates (α-aminoalkyl, β-aminoalkyl, ipso-alkyl).
• Tuning catalytic parameters to control selectivity for α-alkylation, β-alkylation, and ipso-alkylation.

Main Results:

• Demonstrated successful ligand-controlled Ni-catalyzed site-selective and divergent alkyl-alkyl reductive coupling.
• Achieved chemo- and position-selective alkylation of unactivated α-H and β-H bonds in amines.
• Showcased the ability to selectively functionalize one alkyl chain over others with migratable chains.
• Enabled rapid access to three distinct branched aliphatic amine architectures by altering catalytic parameters.

Conclusions:

• The developed Ni-catalyzed reaction provides a powerful and versatile platform for site-selective functionalization of saturated alkyl chains.
• This methodology offers unprecedented synthetic opportunities for constructing complex amine derivatives.
• The ability to access multiple branched aliphatic amine architectures from identical starting materials highlights the reaction's efficiency and divergence.