TY - JOUR
T1 - Chiral N-phosphonyl imine chemistry
T2 - Asymmetric additions of ester enolates for the synthesis of β-amino acids
AU - Han, Jianlin
AU - Ai, Teng
AU - Nguyen, Thao
AU - Li, Guigen
PY - 2008/8
Y1 - 2008/8
N2 - Chiral phosphonyl imines attached by 1-naphthyl protection group were found to react with lithium ester enolates smoothly and give chiral β-amino esters in good yields (70-88%) and up to excellent diastereoselectivity (>99:1 dr). Triisopropoxytitanium (IV) chloride was found to enhance diastereoseletivity when used as the Lewis acid promoter. The chiral auxiliary can be readily removed by treating with HBr to give free amino esters. The absolute structure has been unambiguously determined by converting one of the products into an authentic sample. This reaction provides an easy access to β-amino acid derivatives.
AB - Chiral phosphonyl imines attached by 1-naphthyl protection group were found to react with lithium ester enolates smoothly and give chiral β-amino esters in good yields (70-88%) and up to excellent diastereoselectivity (>99:1 dr). Triisopropoxytitanium (IV) chloride was found to enhance diastereoseletivity when used as the Lewis acid promoter. The chiral auxiliary can be readily removed by treating with HBr to give free amino esters. The absolute structure has been unambiguously determined by converting one of the products into an authentic sample. This reaction provides an easy access to β-amino acid derivatives.
KW - Chiral N-phosphonyl imines
KW - Chiral phosphoramide
KW - Lithium enolate
KW - Triisopropoxytitanium(IV) chloride
KW - β-amino acid
UR - http://www.scopus.com/inward/record.url?scp=47949118819&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=47949118819&partnerID=8YFLogxK
U2 - 10.1111/j.1747-0285.2008.00682.x
DO - 10.1111/j.1747-0285.2008.00682.x
M3 - Article
C2 - 18631372
AN - SCOPUS:47949118819
SN - 1747-0277
VL - 72
SP - 120
EP - 126
JO - Chemical Biology and Drug Design
JF - Chemical Biology and Drug Design
IS - 2
ER -