(R)-2-Methyl-CBS-oxazaborolidine丨CAS 112022-83-0

(R)-2-Methyl-CBS-oxazaborolidine丨CAS 112022-83-0 is a chiral organoboron catalyst developed by Corey, Bakshi, and Shibata (hence "CBS") for enantioselective reductions of prochiral ketones. It is among the most widely used asymmetric catalysts in organic synthesis, particularly for the enantioselective reduction of ketones to secondary alcohols with high enantiomeric excess (ee).
This compound exemplifies the power of chiral catalysis in fine chemical and pharmaceutical manufacturing, offering excellent selectivity, efficiency, and compatibility with various substrates.

1. Enantioselective Ketone Reductions
● Primary Application: (R)-2-Methyl-CBS-oxazaborolidine丨CAS 112022-83-0 acts as a chiral catalyst in the borane-mediated asymmetric reduction of ketones to chiral secondary alcohols.
● When used with borane (BH₃·THF or BH₃·Me₂S), it enables highly enantioselective transformations.
● Tolerates a broad range of substrates, including:
oAromatic and aliphatic ketones
oα,β-unsaturated ketones
oSterically hindered ketones
Example Reaction:
R-CO-R' + BH₃ + (R)-CBS → R-CH(OH)-R' with up to >99% ee

2. Pharmaceutical and API Synthesis
Used extensively in the synthesis of chiral alcohol intermediates, which are building blocks for:
● Chiral drugs and active pharmaceutical ingredients (APIs)
● Agrochemicals
● Natural product derivatives
Notable Examples:
● Intermediates for HIV protease inhibitors
● Non-steroidal anti-inflammatory drugs (NSAIDs)
● Chiral amines and amino alcohols

3. Academic and Industrial Organic Synthesis
● A staple in asymmetric synthesis laboratories worldwide.
● Used in proof-of-concept and process-scale applications due to:
oPredictable performance
oHigh enantiocontrol
oEase of use

√ Exceptional Enantioselectivity
● Routinely delivers >90% to >99% enantiomeric excess (ee) for a wide array of ketones.
● Often considered a benchmark for asymmetric reduction techniques.
√ Mild Reaction Conditions
● Reactions typically run at ambient temperatures.
● Compatible with moisture-sensitive environments (performed under inert atmosphere).
√ High Catalytic Efficiency
● Used in catalytic quantities (typically 5–10 mol%), making it economical for small- to medium-scale synthesis.
√ Versatility
● Applicable to structurally diverse ketones.
● Suitable for both aromatic and aliphatic systems, including challenging substrates.
√ Scalable
● Widely used in gram to kilogram scale manufacturing in pharma and fine chemicals sectors.
● Compatible with common lab and industrial equipment.

Conclusion
(R)-2-Methyl-CBS-oxazaborolidine丨CAS 112022-83-0 is a cornerstone reagent in modern asymmetric synthesis, enabling efficient and highly selective reductions of ketones to chiral alcohols. Its high enantioselectivity, broad substrate compatibility, and scalability have made it indispensable in pharmaceutical R&D, API manufacturing, and academic research.