Frozen Solution-Mediated Asymmetric Synthesis: Control of Enantiomeric Excess

2020 ◽  
Vol 85 (6) ◽  
pp. 4525-4529
Author(s):  
Koki Iijima ◽  
Makoto Harada ◽  
Gaku Fukuhara ◽  
Tetsuo Okada
Keyword(s):  
Asymmetric Synthesis ◽  
Enantiomeric Excess ◽  
Frozen Solution

Asymmetric synthesis of new γ-butenolides via organocatalyzed epoxidation of chalcones

2017 ◽  
Vol 15 (29) ◽  
pp. 6098-6103 ◽  
Author(s):  
Lucas C. C. Vieira ◽  
Bianca T. Matsuo ◽  
Lorena S. R. Martelli ◽  
Mayara Gall ◽  
Marcio W. Paixão ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Enantiomeric Excess ◽  
Chromatographic Purification

A greener three-step sequence, with only one single chromatographic purification, afforded γ-butenolides in moderate overall yield and high enantiomeric excess.

Asymmetric Synthesis of Chiral Tertiary Alcohols in High Enantiomeric Excess

1982 ◽  
pp. 37-53 ◽  
Author(s):  
ERNEST L. ELIEL ◽  
JORMA K. KOSKIMIES ◽  
BRUNO LOHRI ◽  
W. JACK FRAZEE ◽  
SUSAN MORRIS-NATSCHKE ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Enantiomeric Excess ◽  
Tertiary Alcohols ◽  
Chiral Tertiary Alcohols

scholarly journals Isolation of Rhodococcus sp. Strain ECU0066, a New Sulfide Monooxygenase-Producing Strain for Asymmetric Sulfoxidation

2008 ◽  
Vol 75 (2) ◽  
pp. 551-556 ◽  
Author(s):  
Ai-Tao Li ◽  
Jian-Dong Zhang ◽  
Jian-He Xu ◽  
Wen-Ya Lu ◽  
Guo-Qiang Lin
Keyword(s):  
Enzyme Activity ◽  
Asymmetric Synthesis ◽  
Bacterial Strain ◽  
Enantiomeric Excess ◽  
Good Activity ◽  
Rich Medium ◽  
Practical Application ◽  
Chiral Sulfoxides ◽  
Good Potential ◽  
Rhodococcus Sp

ABSTRACT A new and efficient sulfide monooxygenase-producing strain, ECU0066, was isolated and identified as a Rhodococcus sp. that could transform phenylmethyl sulfide (PMS) to (S)-sulfoxide with 99% enantiomeric excess via two steps of enantioselective oxidations. Its enzyme activity could be effectively induced by adding PMS or phenylmethyl sulfoxide (PMSO) directly to a rich medium at the early log phase (6 h) of fermentation, resulting in over 10-times-higher production of the enzyme. This bacterial strain also displayed fairly good activity and enantioselectivity toward seven other sulfides, indicating a good potential for practical application in asymmetric synthesis of chiral sulfoxides.

An improved synthesis of sitophilure

2009 ◽  
Vol 87 (1) ◽  
pp. 30-32 ◽  
Author(s):  
Cuifen Lu ◽  
Junqi Nie ◽  
Guichun Yang ◽  
Zuxing Chen
Keyword(s):  
Asymmetric Synthesis ◽  
Aldol Reaction ◽  
Enantiomeric Excess ◽  
Chiral Auxiliary

The asymmetric synthesis of sitophilure was carried out in 8 steps, with 42% overall yield and 97% enantiomeric excess from propionaldehyde. The synthesis relied on an approach employing an asymmetric acyl-thiazolidinethione propionate aldol reaction to establish two stereogenic centers.Key words: sitophilure, thiazolidinethione, chiral auxiliary, synthesis.

Asymmetric Synthesis of Enantiomerically Enriched a-Amino Acids Containing 2-Furyl- and 2-Thienyl-1,2,4-triazoles in the Side-Chain

2014 ◽  
Vol 69 (4) ◽  
pp. 451-460 ◽  
Author(s):  
Ashot S. Saghyan ◽  
Hayarpi M. Simonyan ◽  
Satenik G. Petrosyan ◽  
Anna F. Mkrtchyan ◽  
Lilit V. Khachatryan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Schiff Base ◽  
Asymmetric Synthesis ◽  
Efficient Method ◽  
Enantiomeric Excess ◽  
Side Chain ◽  
Chiral Auxiliaries ◽  
Enantiomerically Pure ◽  
Dehydroamino Acids ◽  
Hydrolysis Of

An efficient method for the asymmetric synthesis of a-amino acids, containing furyl- and thiophenyl-substituted triazoles in their side-chain, is reported. The strategy relies on Michael addition of 3,4,5-substituted 1,2,4-triazoles to the C=C bond of chiral NiII complexes containing the Schiff base formed from dehydroamino acids (dehydroalanine and (E + Z)-dehydroaminobutyric acid) and from chiral auxiliaries, i. e. (S)-2-N-(N0-benzylprolyl)aminobenzophenone and (S)-2-N- (N0-2-chlorobenzylprolyl) aminobenzophenone. The reactions proceeded with good to very good diastereoselectivity. Hydrolysis of the diastereomeric mixtures of metal complexes afforded the enantiomerically pure a-amino acids with high enantiomeric excess (ee> 98%).

Sign in / Sign up

Export Citation Format

Share Document