37589-40-5

Upstream product

• 1798-60-3 (R)-1-hydroxy-1-phenyl-2-propanone 
• 75-04-7 ethylamine 
• 492-41-1 (1R,2S)-norephedrine 
• 75-05-8 acetonitrile 
• 100390-41-8 (+/-)-3-ethyl-4r-methyl-5t-phenyl-oxazolidin-2-one 
• 74-96-4 ethyl bromide 
• 917-64-6 methyl magnesium iodide 
• 120443-82-5 (R)-2-phenyl-2-(trimethylsiloxy)acetonitrile 
• 877384-26-4 2-(N-ethyl-N-benzyloxycarbonyl-amino)-1-phenyl-1-propanone 

Downstream Products

• 55116-50-2 N-Ethyl-N-((1S,2S)-2-hydroxy-1-methyl-2-phenyl-ethyl)-acetamide 

Relevant academic research and scientific papers

Highly diastereoselective catalytic Meerwein-Ponndorf-Verley reductions

Very practical synthesis of ephedrine analogues in high yields and enantiopurity was realized by a highly diastereoselective Meerwein-Ponndorf- Verley (MPV) reduction of protected α-amino aromatic ketones using catalytic aluminum isopropoxide. The high anti selectivity resulted from the chelation of the nitrogen anion to the aluminum. In contrast, high syn selectivity was obtained with α-alkoxy ketones and other compounds via Felkin-Ahn control.

Nitriles under palladium-catalyzed hydrogenation conditions as substitutes for aldehydes in the reaction with 1,2-amino alcohols: Formation of 1,3-oxazolidines and reductive N-alkylation

At room temperature, the presence of hydrogen and catalytic amounts of Pd/C induced the formation of 1,3-oxazolidines from nitriles and 1,2-amino alcohols. The subsequent reductive cleavage of the NC-O bond of these heterocycles occurred under the same conditions. Thus, this methodology provides a new one-pot N-alkylation of 19-amino alcohols using nitriles as reagents with yields up to 98%.

Stereoselective synthesis of (1R)- and (1R,2S)-1-aryl-2-alkylamino alcohols from (R)-cyanohydrins

Hydrogenation of (R)-cyanohydrins (R)-1 with LiAlH4 occurs without racemization to give the (R)-2-amino alcohols (R)-3. (1R,2S)-2-Amino alcohols (1R,2S)-4 are obtained with high diastereoselectivity by addition of methyl Grignard to O-silyl protected cyanohydrins (R)-2 and subsequent hydrogenation with NaBH4. The N-alkylated 2-amino alcohols (R)-8 and (1R,2S)-9 can be prepared either by reductive alkylation of the corresponding 2-amino alcohols (R)-3 and (1R,2S)-4, respectively, or by a transimination reaction of the Grignard addition products with primary amines and subsequent hydrogenation with NaBH4. The lower diastereoselectivity of hydrogenation in case of the N-alkylmino compounds in comparison to the N-unsubstituted imines is explained by a weaker chelating effect.