Catalytic asymmetric syntheses of tyrosine surrogates.
Amino acid esters 5-11 as tyrosine mimics have been synthesized in excellent enantioselectivity (up to 99.6% ee) and in good overall chemical yields. The key step in the sequence was the Burk's [Rh(COD)(2R,5R)-Et-DuPhos]BF4-catalyzed asymmetric hydrogenation of enamides with a variety of reactive functional groups.
Han
Xiaojun
X
Neuroscience Discovery Chemistry, Research & Development, Bristol-Myers Squibb Company, 5 Research Parkway, Wallingford, Connecticut 06492, USA. xiaojun.han@bms.com
Civiello
Rita L
RL
Fang
Haiquang
H
Wu
Dedong
D
Gao
Qi
Q
Chaturvedula
Prasad V
PV
Macor
John E
JE
Dubowchik
Gene M
GM
D000596:Amino Acids / Q000737:chemistry; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis*; D006865:Hydrogenation; D018716:Molecular Mimicry; D013237:Stereoisomerism; D014443:Tyrosine / Q000737:chemistry*
D000596:Amino Acids; D004952:Esters; D014443:Tyrosine