Reliably Regioselective Dialkyl Ether Cleavage with Mixed Boron Trihalides

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Unsymmetrical alkyl ethers are common functional groups.
• Cleavage of these ethers often lacks regioselectivity or requires harsh conditions.
• Limited methods exist for synthesizing acyclic dialkoxyboryl chlorides.

Purpose of the Study:

• To develop a regioselective protocol for cleaving unsymmetrical alkyl ethers.
• To improve upon existing ether cleavage methods using boron trihalides.
• To synthesize acyclic dialkoxyboryl chlorides as versatile intermediates.

Main Methods:

• Utilizing a mixture of trihaloboranes for ether cleavage.
• Employing the developed protocol for the synthesis of dialkyl boronate esters.

Main Results:

• Achieved regioselective cleavage of unsymmetrical alkyl ethers to alkyl alcohols and alkyl bromides.
• Demonstrated improved reactivity, regioselectivity, and yield compared to boron tribromide (BBr₃) alone.
• Successfully synthesized acyclic (B-Cl) dialkyl boronate esters.

Conclusions:

• The described protocol offers an efficient and selective method for alkyl ether cleavage.
• The use of mixed trihaloboranes enhances reactivity and selectivity.
• This work provides access to valuable dialkyl boronate ester synthons in main-group chemistry.