Copper-catalysed borylation of aryl chlorides

Area of Science:

• Organic Chemistry
• Catalysis
• Organoboron Chemistry

Background:

• Arylboronic esters are crucial building blocks in organic synthesis, particularly in cross-coupling reactions.
• Efficient synthesis of arylboronic esters from aryl chlorides remains challenging due to the inertness of the C-Cl bond.

Purpose of the Study:

• To develop a novel copper-catalyzed method for the borylation of aryl chlorides.
• To investigate the scope and limitations of the developed catalytic system.

Main Methods:

• Utilized a readily prepared N-heterocyclic carbene (NHC)-stabilized copper catalyst.
• Employed potassium tert-butoxide (KOtBu) as the base and bis(pinacolato)diboron (B2pin2) as the boron source.
• Screened various aryl chlorides with diverse electronic and steric properties.

Main Results:

• Achieved the first copper-catalyzed borylation of a wide range of aryl chlorides.
• Obtained corresponding arylboronic esters in good yields.
• Demonstrated broad functional group tolerance and applicability of B2neop2 as an alternative boron reagent.

Conclusions:

• The developed NHC-Cu catalyzed borylation offers an efficient and versatile route to arylboronic esters from aryl chlorides.
• This method provides a valuable tool for organic synthesis, enabling access to diverse organoboron compounds.