Cyclohexylcarbonitriles: diastereoselective arylations with TMPZnCl·LiCl

Area of Science:

• Organic Chemistry
• Catalysis
• Medicinal Chemistry

Background:

• Substituted cyclohexanecarbonitriles are important building blocks in medicinal chemistry.
• Developing efficient and diastereoselective synthetic methods is crucial for pharmaceutical development.

Purpose of the Study:

• To investigate the diastereoselective coupling of zincated nitriles with aryl bromides.
• To explore the influence of steric and electronic effects on diastereoselectivity in this reaction.

Main Methods:

• Deprotonation of substituted cyclohexanecarbonitriles using TMPZnCl·LiCl.
• Palladium-catalyzed (Pd(OAc)(2)) cross-coupling with aryl bromides using S-Phos ligand.

Main Results:

• Achieved diastereoselective coupling of zincated nitriles with aryl bromides.
• Demonstrated that steric and electronic effects significantly influence diastereoselectivity.
• Observed virtually complete diastereocontrol with 4-t-butyl-, 4-TBSO-, and 2-Me-cyclohexanecarbonitriles.
• Reported modest diastereoselectivity with 4-i-Pr-, 4-Me-, and 3-Me-cyclohexanecarbonitriles.

Conclusions:

• The developed method provides a valuable tool for the synthesis of substituted cyclohexanecarbonitrile derivatives.
• The observed diastereoselectivity trends offer insights for designing targeted pharmaceutical compounds.
• This work facilitates the efficient construction of complex molecules for drug discovery.