Strain Release of Donor-Acceptor Cyclopropyl Boronate Complexes

Area of Science:

• Organic Chemistry
• Organometallic Chemistry

Background:

• Boronate complexes are versatile synthetic intermediates.
• Donor-acceptor cyclopropanes exhibit unique reactivity patterns.

Purpose of the Study:

• To investigate the reactivity of enantioenriched cyclopropyl boronate complexes.
• To develop an atom-efficient synthesis of chiral γ-carbonyl boronic esters.

Main Methods:

• Activation of cyclopropyl boronate complexes with Lewis acids.
• Concerted 1,2-metalate rearrangement and ring-opening reactions.
• Three-component reaction via in situ alkylation.

Main Results:

• Demonstrated a novel Lewis acid-catalyzed rearrangement of cyclopropyl boronate complexes.
• Achieved moderate to excellent yields of optically active γ-carbonyl boronic esters.
• Established complete enantiospecificity in the transformation.
• Developed a three-component variant for broader applicability.

Conclusions:

• The described method provides efficient access to chiral γ-carbonyl boronic esters.
• The products serve as valuable chiral building blocks for further synthesis.
• This work expands the synthetic utility of boronate complexes.