Copper Catalyzed sp³ C-H Etherification with Acyl Protected Phenols.

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Acyl protected phenols (AcOAr) are common precursors in organic synthesis.
• C-H functionalization offers a direct route to complex molecules, minimizing pre-functionalization steps.
• Copper catalysis is increasingly utilized for C-H activation and bond formation.

Purpose of the Study:

• To develop a novel copper-catalyzed sp3 C-H etherification reaction.
• To explore the scope and selectivity of the reaction with various substrates.
• To elucidate the catalytic mechanism involving copper intermediates.

Main Methods:

• Utilized copper(I) β-diketiminato catalysts for the etherification reaction.
• Employed tert-butyl hydroperoxide (tBuOO tBu) as the oxidant.
• Investigated the functionalization of primary, secondary, and tertiary C-H bonds in substrates (R-H).

Main Results:

• Successfully synthesized a variety of alkyl aryl ethers (R-OAr) from AcOAr and R-H.
• Demonstrated selectivity for the formation of hindered, tertiary C-OAr bonds.
• Mechanistic studies implicated copper(II) phenolates ([CuII]-OAr) in the C-O bond formation.

Conclusions:

• Developed an efficient copper-catalyzed sp3 C-H etherification of protected phenols.
• The reaction provides a selective route to sterically demanding alkyl aryl ethers.
• The proposed mechanism involves key copper(II) intermediates formed via transesterification.