Nitrile Biotransformations for the Synthesis of Highly Enantioenriched β-Hydroxy and β-Amino Acid and Amide Derivatives: A General and Simple but Powerful and Efficient Benzyl Protection Strategy To Increase Enantioselectivity of the Amidase
摘要:
Biotransformations of a number of racemic beta-hydroxy and beta-amino nitrile derivatives were studied using Rhodococcus erythropolis AJ270, the nitrile hydratase and amidase-containing microbial whole cell catalyst, under very mild conditions. The overall enantioselectivity of nitrile biotransformations was governed predominantly by the amidase whose enantioselectivity was switched on remarkably by an O- and a N-benzyl protection group of the Substrates. While biotransformations of beta-hydroxy and beta-amino alkanenitriles gave low yields of amide and acid products of very low enantiomeric purity, introduction of a simple benzyl protection group on the beta-hydroxy and beta-amino of nitrile substrates led to the formation of highly enantioenriched beta-benzyloxy and beta-benzylamino amides and acids in almost quantitative yield. The easy protection and deprotection operations, high chemical yield, and excellent enantioselectivity render the nitrile biotransformation a useful protocol in the synthesis of enantiopure beta-hydroxy and beta-amino acids.
Process for producing either optically active n-substituted beta-amino acid and optically active n-substituted beta-amino acid ester or optically active n-substituted 2-homopipecolic acid and optically active n-substituted 2-homopipecolic acid ester
申请人:Miyata Hiroyuki
公开号:US20050170473A1
公开(公告)日:2005-08-04
The present invention discloses a process which comprises selectively hydrolyzing one enantiomer of racemic mixtures of an N-substituted β-amino acid alkyl ester or N-substituted 2-homopipecolic acid ester represented by the formula (I):
wherein Ar, R
1
, R
2
, R
3
, R
4
and R
5
are the same as defined in the specification,
in the presence of a hydrolase to form an optically active ((R) or (S))-N-substituted-β-amino acid or optically active ((R) or (S))-N-substituted 2-homopipecolic acid represented by the formula (II):
and simultaneously to obtain an unreacted optically active ((S) or (R))-N-substituted β-amino acid alkyl ester or unreacted optically active ((S) or (R))-N-substituted 2-homopipecolic acid ester represented by the formula (III):
which has a reverse steric absolute configuration to that of the compound represented by the formula (II).
PROCESS FOR PRODUCING EITHER OPTICALLY ACTIVE N-SUBSTITUTED BETA-AMINO ACID AND OPTICALLY ACTIVE N-SUBSTITUTED BETA-AMINO ACID ESTER OR OPTICALLY ACTIVE N-SUBSTITUTED 2-HOMOPIPECOLIC ACID AND OPTICALLY ACTIVE N-SUBSTITUTED 2-HOMOPIPECOLIC ACID ESTER
申请人:Ube Industries, Ltd.
公开号:EP1493819A1
公开(公告)日:2005-01-05
The present invention discloses a process which comprises selectively hydrolyzing one enantiomer of racemic mixtures of an N-substituted β-amino acid alkyl ester or N-substituted 2-homopipecolic acid ester represented by the formula (I):
wherein Ar, R1, R2, R3, R4 and R5 are the same as defined in the specification,
in the presence of a hydrolase to form an optically active ((R) or (S))-N-substituted β-amino acid or optically active ((R) or (S))-N-substituted 2-homopipecolic acid represented by the formula (II):
and simultaneously to obtain an unreacted optically active ((S) or (R))-N-substituted β-amino acid alkyl ester or unreacted optically active ((S) or (R))-N-substituted 2-homopipecolic acid ester represented by the formula (III):
which has a reverse steric absolute configuration to that of the compound represented by the formula (II).
Nitrile Biotransformations for the Synthesis of Highly Enantioenriched β-Hydroxy and β-Amino Acid and Amide Derivatives: A General and Simple but Powerful and Efficient Benzyl Protection Strategy To Increase Enantioselectivity of the Amidase
作者:Da-You Ma、De-Xian Wang、Jie Pan、Zhi-Tang Huang、Mei-Xiang Wang
DOI:10.1021/jo800074k
日期:2008.6.1
Biotransformations of a number of racemic beta-hydroxy and beta-amino nitrile derivatives were studied using Rhodococcus erythropolis AJ270, the nitrile hydratase and amidase-containing microbial whole cell catalyst, under very mild conditions. The overall enantioselectivity of nitrile biotransformations was governed predominantly by the amidase whose enantioselectivity was switched on remarkably by an O- and a N-benzyl protection group of the Substrates. While biotransformations of beta-hydroxy and beta-amino alkanenitriles gave low yields of amide and acid products of very low enantiomeric purity, introduction of a simple benzyl protection group on the beta-hydroxy and beta-amino of nitrile substrates led to the formation of highly enantioenriched beta-benzyloxy and beta-benzylamino amides and acids in almost quantitative yield. The easy protection and deprotection operations, high chemical yield, and excellent enantioselectivity render the nitrile biotransformation a useful protocol in the synthesis of enantiopure beta-hydroxy and beta-amino acids.