33442-47-6Relevant articles and documents
Auxiliary-Directed Diastereoselectivity in the Claisen Rearrangement of Glycolate Esters
Kallmerten, James,Gould, Thomas J.
, p. 1152 - 1155 (1986)
Examples are presented in which the stereochemical course of the Claisen rearrangement of allylic glycolates is controlled by a chiral substituent appended to the glycolate hydroxyl.
Catalytic asymmetric synthesis of esters from ketenes
Wiskur, Sheryl L.,Fu, Gregory C.
, p. 6176 - 6177 (2005)
By building on elementary principles of Bronsted acid-base chemistry, a nucleophile-catalyzed method for the asymmetric synthesis of esters from ketenes has been transformed into a much more versatile and effective Bronsted acid-catalyzed process. The product aryl esters can be converted into useful derivatives, such as enantioenriched alcohols and carboxylic acids. Copyright
Identification of an Esterase Isolated Using Metagenomic Technology which Displays an Unusual Substrate Scope and its Characterisation as an Enantioselective Biocatalyst
Gavin, Declan P.,Murphy, Edel J.,Foley, Aoife M.,Castilla, Ignacio Abreu,Reen, F. Jerry,Woods, David F.,Collins, Stuart G.,O'Gara, Fergal,Maguire, Anita R.
, p. 2466 - 2474 (2019/03/11)
Evaluation of an esterase annotated as 26D isolated from a marine metagenomic library is described. Esterase 26D was found to have a unique substrate scope, including synthetic transformations which could not be readily effected in a synthetically useful manner using commercially available enzymes. Esterase 26D was more selective towards substrates which had larger, more sterically demanding substituents (i. e. iso-propyl or tert-butyl groups) on the β-carbon, which is in contrast to previously tested commercially available enzymes which displayed a preference for substrates with sterically less demanding substituents (e.g. methyl group) at the β-carbon. (Figure presented.).
Rh-Catalyzed Asymmetric Hydrogenation of β-Branched Enol Esters for the Synthesis of β-Chiral Primary Alcohols
Liu, Chong,Yuan, Jing,Zhang, Jian,Wang, Zhihui,Zhang, Zhenfeng,Zhang, Wanbin
, p. 108 - 111 (2018/01/17)
An asymmetric hydrogenation of β-branched enol esters has been developed for the first time, providing a new route for the synthesis of β-chiral primary alcohols. Using a (S)-SKP-Rh complex bearing a large bite angle and enol ester substrates possessing an O-fomyl directing group, the desired products were obtained in quantitative yields and with excellent enantioselectivities.
Impact of variation of the acyl group on the efficiency and selectivity of the lipase-mediated resolution of 2-phenylalkanols
Foley, Aoife M.,Gavin, Declan P.,Joniec, Ilona,Maguire, Anita R.
, p. 1144 - 1153 (2017/09/15)
By tuning the steric properties of the acyl group to control the efficiency and selectivity of the resolution, 2-phenyl-1-propanol 1a was prepared by lipase-catalysed hydrolysis using a short-chain acyl group, with E-values of up to 66 (ee up to 95%). 2-Phenylbutan-1-ol 1b was similarly resolved (up to 86% ee) using the optimised conditions, while the ester of the more sterically demanding 3-methyl-2-phenylbutan-1-ol 1c proved resistant to enzymatic hydrolysis under these conditions.
Synthesis and Antibacterial Activity of Four Stereoisomers of the Spider-Pathogenic Fungus Metabolite Torrubiellone D
Bruckner, Sebastian,Bilitewski, Ursula,Schobert, Rainer
supporting information, p. 1136 - 1139 (2016/03/15)
Four stereoisomers of the spider-pathogenic fungus metabolite torrubiellone D were synthesized for the first time in 10% overall yield starting from l-tyrosine or d-tyrosine. The 3-decatrienoyl side chain was assembled and attached via (E)-selective HWE and Wittig olefinations. Their antibiotic activities against drug-susceptible Escherichia coli strains differed considerably.
Filling the gaps in the challenging asymmetric hydroboration of 1,1-disubstituted alkenes with simple phosphite-based phosphinooxazoline iridium catalysts
Magre, Marc,Biosca, Maria,Pmies, Oscar,Diguez, Montserrat
, p. 114 - 120 (2015/01/30)
We have identified a readily accessible phosphinooxazoline-based phosphite-oxazoline catalytic system, (S)-4-isopropyl-2-{2-[(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite]-phenyl}-2-oxazoline (L1a), that can hydroborate a range of 1,1-disubstituted aryl olefins with high enantioselectivity (up to 94%), excellent yields and perfect regioselectivity. The new phosphite-oxazoline ligands efficiently hydroborate a broader range of olefins than previous phosphinooxazoline ligands. In particular, a wide range of α-tert-butylstyrenes can be hydroborated that bear aryl substituents with different electronic and steric properties, which complements previous results with N-heterocyclic copper catalysts, the only other system reported to date that has achieved these reactions.
Catalytic enantioselective ethylalumination of terminal alkenes: Substrate effects and absolute configuration assignment
Parfenova, Lyudmila V.,Kovyazin, Pavel V.,Tyumkina, Tatyana V.,Makrushina, Alyona V.,Khalilov, Leonard M.,Dzhemilev, Usein M.
, p. 124 - 135 (2015/02/19)
The chemo- and enantioselectivity of the reaction of alkenes with AlEt3 catalyzed by bis(1-neomenthylindenyl)zirconium dichloride has been studied. The reaction with linear alkenes in a chlorinated solvent (CH2Cl2) gives m
A new mechanism of enantioselectivity toward chiral primary alcohol by lipase from Pseudomonas cepacia
Meng, Xiao,Guo, Li,Xu, Gang,Wu, Jian-Ping,Yang, Li-Rong
, p. 109 - 115 (2014/12/11)
The stereo-recognition of chiral primary alcohols by lipase from Pseudomonas cepacia was found to deviate from earlier observations. Enantioselectivity toward 14 pairs of chiral primary alcohol esters by this lipase was dependent on the existence of an Onon-α(oxygen at non-α-position of the acyloxy group) in the alcohol moiety, and decreased as the size of the acyl moiety increased. Chemical modification on the lipase and molecular dynamics simulations indicated that Tyr29located within the catalytic cavity forms a hydrogen bond with the Onon-αof the preferred enantiomer of the primary alcohol ester. However, a larger acyl moiety suffered stronger hindrance from the catalytic cavity wall of the lipase, pushing the Onon-αaway from Tyr29, and thus weakening the stereo-recognition.
Asymmetric rearrangement of racemic epoxides catalyzed by chiral Br?nsted acids
Zhuang, Minyang,Du, Haifeng
supporting information, p. 1460 - 1462 (2013/05/08)
This paper describes a chiral Br?nsted acid catalyzed asymmetric 1,2-rearrangement of racemic epoxides via a hydrogen-shift process for the synthesis of chiral aldehydes, and, followed by a reduction, a variety of optically active alcohols can be furnished in moderate yields with up to 50% ee. Especially, a facile one-pot synthesis of chiral alcohols directly from simple alkenes by a sequential epoxidation, rearrangement, and reduction has also been realized.
