Asymmetric Allylation of -Ketoester-Derived N-Benzoylhydrazones Promoted by Chiral Sulfoxides/N-Oxides Lewis Bases: Highly Enantioselective Synthesis of Quaternary -Substituted -Allyl--Amino Acids

作者：Reyes Rangel Gloria; Bandala Yamir; Garcia Flores Fred; Juaristi Eusebio^*

来源：Chirality, 2013, 25(9): 529-540.

DOI：10.1002/chir.22159

• Asymmetric allylation
• chiral sulfoxides
• -allyl--amino acids
• quaternary carbons
• Lewis bases

Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of -keto ester N-benzoylhydrazone derivatives 3a, 3b, 3c, 3d, 3e, 3f, 3g to generate the corresponding N-benzoylhydrazine derivatives 4a, 4b, 4c, 4d, 4e, 4f, 4g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a, 4b were subsequently treated with SmI2, and the resulting amino esters 5a, 5b with LiOH to obtain quaternary -substituted -allyl -amino acids 6a, 6b, whose absolute configuration was assigned as (S), with fundament on chemical correlation and electronic circular dichroism (ECD) data. Chirality 25:529-540, 2013.

• 出版日期2013-9