Synthesis of gamma-amino esters via Mn-mediated radical addition to chiral gamma-hydrazonoesters.
Highly stereoselective Mn-mediated couplings of alkyl iodides with chiral N-acylhydrazones bearing ester functionality afford a series of gamma-hydrazino esters, including gamma-substituted, alpha,gamma-disubstituted, and alpha,alpha,gamma-trisubstituted examples. In contrast to prior work with chiral N-acylhydrazones, high stereoselectivity was observed even in the absence of Lewis acid. Microwave-assisted acylation with trifluoroacetic anhydride and reductive N-N bond cleavage provided the gamma-amino ester functionality in a synthetically useful N-TFA-protected form.
Friestad
Gregory K
GK
Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA. gregory-friestad@uiowa.edu
Banerjee
Koushik
K
D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D004952:Esters; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry; D006835:Hydrazones / Q000737:chemistry*; D006847:Hydrocarbons, Iodinated / Q000737:chemistry*; D007204:Indium / Q000737:chemistry; D008345:Manganese / Q000737:chemistry*; D008872:Microwaves; D015394:Molecular Structure; D013237:Stereoisomerism
D000596:Amino Acids; D004952:Esters; D006834:Hydrazines; D006835:Hydrazones; D006847:Hydrocarbons, Iodinated; D007204:Indium; C020758:indium trichloride; D008345:Manganese