Diastereoselective Addition of Metal α-Fluoroenolates of Carboxylate Esters to N-tert-Butylsulfinyl Imines: Synthesis of α-Fluoro-β-amino Acids.
We report a diastereoselective addition reaction of fluoroacetate and α-alkylated fluoroacetate to N-tert-butylsulfinyl imines. This method provides a concise route to α-fluoro-β-amino acids containing fluorinated quaternary stereogenic carbon centers with very good yields and high diastereoselectivities. This protocol has the benefit of using abundant and readily accessible starting materials and is operationally simple. Additionally, the stereochemical outcome of the present reaction was different from that of the previously known addition of comparable nonfluorinated, brominated, and chlorinated enolates to N-sulfinyl imines, suggesting that an open transition state (rather than a closed one) is involved in the current fluoroalkylation reaction.
Department of Chemistry and Chemical Engineering, Shanghai University of Engineering Science , 333 Longteng Road, Shanghai 201620, China.
Huaqi
H
Shang
Department of Chemistry and Chemical Engineering, Shanghai University of Engineering Science , 333 Longteng Road, Shanghai 201620, China.
Ya
Y
Li
Department of Chemistry and Chemical Engineering, Shanghai University of Engineering Science , 333 Longteng Road, Shanghai 201620, China.
Xiang
X
Li
Department of Chemistry and Chemical Engineering, Shanghai University of Engineering Science , 333 Longteng Road, Shanghai 201620, China.
Xinfeng
X
Ren
D000478:Alkylation; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D000596:Amino Acids; D002264:Carboxylic Acids; D006845:Hydrocarbons, Fluorinated; D007097:Imines; D008670:Metals