180187-02-4

Upstream product

• 127927-55-3 (2S,3R)-2-(dibenzylamino)-1-phenylpentan-3-ol 
• 111138-83-1 N,N-dibenzyl-L-phenylalanine benzyl ester 
• 111060-52-7 (S)-2-(dibenzylamino)-3-phenylpropan-1-ol 
• 123054-12-6 (2S)-N,N-dibenzylphenylalaninal 
• 3182-95-4 L-Phenylalaninol 

Downstream Products

• 114745-01-6 (4S,5R)-4-Benzyl-5-ethyl-oxazolidin-2-one 

Relevant academic research and scientific papers

Pyridoxal-Catalyzed Racemization of α-Aminoketones Enables the Stereodivergent Synthesis of 1,2-Amino Alcohols Using Ketoreductases

Differentially substituted 1,2-amino alcohols are a prevalent motif in a variety of pharmaceutical and agrochemical molecules. Dynamic kinetic resolutions (DKRs) that involve the asymmetric reduction of α-amino ketones are attractive for preparing this motif; however, methods for racemizing the stereogenic α-carbon under mild conditions are underdeveloped. Here we report a chemoenzymatic DKR involving ketoreductases (KREDs), in which pyridoxal-5-phosphate (PLP) is used to catalyze racemization of the starting racemic α-aminoketone. This strategy enables access to a variety of 1,2-amino alcohols with high levels of diastereo- and enantioselectivity. Using commercially available KREDs, all four possible stereoisomers can be accessed, highlighting a benefit to this approach.

Direct stereoselective synthesis of enantiomerically pure anti -β-amino alcohols

Enantiomerically pure anti-β-amino alcohols were synthesized from optically pure α-(N,N-dibenzylamino)benzyl esters, derived from α-amino acids, by the sequential reduction to aldehyde with DIBAL-H at -78 °C and subsequent in situ addition of Grignard reagents. Besides anti-β-amino alcohols, anti-2-amino-1,3-diols and anti-3-amino-1,4-diols were obtained in good yields (60-95%) and excellent stereoselectivity (de > 95%). Our technique is compatible with free hydroxyl groups present in the substrate. To demonstrate the versatility of the method, spisulosine and sphinganine were synthesized in two steps from the appropriate N,N-dibenzyl-l-aminobenzyl ester in 42% and 45% yield, respectively.

Vanadium-catalyzed asymmetric oxidation of sulfides using Schiff base ligands derived from ss-amino alcohols with two stereogenic centers

Novel Schiff base ligands derived from ss-amino alcohols with two stereogenic centers were prepared and. used in the preparation of optically pure sulfoxides by using aqueous hydrogen peroxide as the oxidant. A variety of sulfides were smoothly converted into the corresponding sulfoxides cata-lyzed by the chiral vanadium-Schiff base complex. Good yields (>80%) with excellent: enantioselectivities (>99%ee) were obtained in most cases.

Synthesis of enantiopure syn-β-amino alcohols. A simple case of chelation-controlled additions of diethylzinc to α-(dibenzylamino) aldehydes

Enantiomerically pure syn-2-amino alcohols 6 are prepared by addition of diethylzinc to chiral α-(dibenzylamino) aldehydes 4. The addition is highly stereoselective, leading to syn-2-(dibenzylamino) alcohols 5 with excellent diastereomeric excesses (76-98%). Debenzylation of 5 by hydrogenolysis on Pearlman's catalyst yields quantitatively the amino alcohols 6.