133576-75-7

Upstream product

• 628-77-3 1,5-diiodopentane 
• 37577-28-9 (1S,2R)-(+)-norphedrine 
• 111-24-0 1,5-dibromo-pentane 

Downstream Products

• 103-79-7 1-phenyl-acetone 

Relevant academic research and scientific papers

Enantioselective Conjugate Addition of Catalytically Generated Zinc Homoenolate

We report herein an enantioselective conjugate addition reaction of a zinc homoenolate, catalytically generated via ring opening of a cyclopropanol, to an α,β-unsaturated ketone. The reaction is promoted by a zinc aminoalkoxide catalyst generated from Et2Zn and a chiral β-amino alcohol to afford 1,6-diketones, which undergo, upon heating, intramolecular aldol condensation to furnish highly substituted cyclopentene derivatives with good to high enantioselectivities. The reaction has proved applicable to various 1-substituted cyclopropanols as well as chalcones and related enones. The chiral amino alcohol has proved to enable ligand-accelerated catalysis of the homoenolate generation and its conjugate addition. Positive nonlinear effects and lower reactivity of a racemic catalyst have been observed, which can be attributed to a stable and inactive heterochiral zinc aminoalkoxide dimer.

Chiral ytterbium complex-catalyzed direct asymmetric aldol-tishchenko reaction: Synthesis of anti-1,3-diols

The asymmetric aldol-Tishchenko reaction of aromatic aldehydes with aliphatic and aromatic ketones has been developed as an efficient strategy for the synthesis of anti-1,3-diols in good yield with high diastereo-control and good levels of enantiose-lectivity. This domino-type reaction is catalyzed by a chiral ytterbium complex that promotes both the aldol reaction through enolization of the carbon yl compound and the Evans-Tishchenko reduction of the aldol intermediate. The stereochemistry of the resulting diols is also investigated and finally proved by using CD techniques.

New chiral catalysts for the highly enantioselective addition of diethylzinc to aldehydes

Optically active amino thioacetate derivatives of (+)-norephedrine were found to act as effective catalysts for enantioselective addition of diethylzinc to aldehydes. This reaction provided optically active secondary alcohols with e.e. of up to >99%.

ENANTIOSELECTIVE CONJUGATE ADDITION OF DIETHYLZINC TO ENONES USING CHIRAL β-AMINOALCOHOL AS CHIRAL CATALYST OR LIGAND

Optically active β-substituted ketones of up to 94percent e.e. were synthesized by the enantioselective conjugate addition of diethylzinc to enones in the presence of either a catalyic or stoichometric amount of chiral β-aminoalcohol.