103966-61-6Relevant articles and documents
A tandem and fully enzymatic procedure for the green resolution of chiral alcohols: Acylation and deacylation in non-aqueous media
Wang, Bo,Jiang, Ling,Wang, Jue,Ma, Jingbo,Liu, Min,Yu, Hongwei
, p. 980 - 985 (2011)
A green and fully enzymatic procedure for the resolution of chiral alcohols through lipase/esterase-catalyzed acylation and subsequent lipase-catalyzed aminolysis using anhydrous ammonia was demonstrated. Both enantiomers can be obtained in high ee values (up to >99%) under ambient reaction conditions. The solvent and acyl donors can be recycled, and the enzyme can be reused for up to five times.
Efficient dynamic kinetic resolution of racemic secondary alcohols by a chemoenzymatic system using bifunctional iridium complexes with C-N chelate amido ligands
Sato, Yasuhiro,Kayaki, Yoshihito,Ikariya, Takao
, p. 3635 - 3637 (2012)
The combined catalyst system of bifunctional amidoiridium complexes derived from benzylic amines with CALB was found to provide a range of chiral acetates from racemic secondary alcohols in excellent yields with nearly perfect enantioselectivities via dyn
Air-stable racemization catalyst for dynamic kinetic resolution of secondary alcohols at room temperature
Kim, Namdu,Ko, Soo-Byung,Min, Serk Kwon,Kim, Mahn-Joo,Park, Jaiwook
, p. 4523 - 4526 (2005)
(Chemical Equation Presented) A novel racemization catalyst was synthesized for the dynamic kinetic resolution (DKR) of alcohols with a lipase at room temperature in the air. Furthermore, a polymer-supported derivative was also synthesized and tested as a recyclable catalyst for the aerobic DKR of alcohols.
Development of an improved immobilized CAL-B for the enzymatic resolution of a key intermediate to odanacatib
Truppo, Matthew D.,Hughes, Gregory
, p. 1033 - 1035 (2011)
An immobilized form of Candida antarctica lipase B (CAL-B) has been developed with enhanced stability and activity compared to commercially available preparations. The immobilized CAL-B is more active, and 15 times more stable than the previously used preparation. This permits a continuous dynamic kinetic resolution process that is significantly less expensive than the original batch process, and with a 3-fold reduction in the process E-factor.
Practical ruthenium/lipase-catalyzed asymmetric transformations of ketones and enol acetates to chiral acetates.
Jung,Koh,Kim,Park
, p. 2487 - 2490 (2000)
Ketones were asymmetrically transformed to chiral acetates by one-pot processes using a lipase and an achiral ruthenium complex under 1 atm of hydrogen gas in ethyl acetate. Molecular hydrogen was also effective for the transformation of enol acetates to chiral acetates without additional acyl donors with the same catalyst system.
Photoactivated racemization catalyst for dynamic kinetic resolution of secondary alcohols
Do, Youngshil,Hwang, In-Chul,Kim, Mahn-Joo,Park, Jaiwook
, p. 5740 - 5742 (2010)
Household fluorescent light activates a diruthenium complex to generate catalytic species highly active for the racemization of secondary alcohols under ambient conditions. This catalyst system is applicable for the chemoenzymatic dynamic kinetic resolution of racemic alcohols to give optically pure acetates under mild conditions.
Sustainable electrochemical decarboxylative acetoxylation of aminoacids in batch and continuous flow
K?ckinger, Manuel,Hanselmann, Paul,Roberge, Dominique M.,Geotti-Bianchini, Piero,Kappe, C. Oliver,Cantillo, David
, p. 2382 - 2390 (2021)
Introduction of acetoxy groups to organic molecules is important for the preparation of many active ingredients and synthetic intermediates. A commonly used and attractive strategy is the oxidative decarboxylation of aliphatic carboxylic acids, which entails the generation of a new C(sp3)-O bond. This reaction has been traditionally carried out using excess amounts of harmful lead(iv) acetate. A sustainable alternative to stoichiometric oxidants is the Hofer-Moest reaction, which relies on the 2-electron anodic oxidation of the carboxylic acid. However, examples showing electrochemical acetoxylation of amino acids are scarce. Herein we present a general and scalable procedure for the anodic decarboxylative acetoxylation of amino acids in batch and continuous flow mode. The procedure has been applied to the derivatization of several natural and synthetic amino acids, including key intermediates for the synthesis of active pharmaceutical ingredients. Good to excellent yields were obtained in all cases. Transfer of the process from batch to a continuous flow cell signficantly increased the reaction throughput and space-time yield, with excellent product yields obtained even in a single-pass. The sustainability of the electrochemical protocol has been examined by evaluating its green metrics. Comparison with the conventional method demonstrates that an electrochemical approach has a significant positive effect on the greenness of the process.
Overberger,Kamath
, p. 446 (1963)
Discovery and Redesign of a Family VIII Carboxylesterase with High (S)-Selectivity toward Chiral sec-Alcohols
Park, Areum,Park, Seongsoon
, p. 2397 - 2402 (2022/02/17)
Highly enantioselective lipase has been widely utilized in the preparation of versatile enantiopure chiral sec-alcohols through kinetic or dynamic kinetic resolution. Lipase is intrinsically (R)-selective, and it is difficult to obtain (S)-selective lipase. Recent crystal structures of a family VIII carboxylesterase have revealed that the spatial array of its catalytic triad is the mirror image of that of lipase but with a catalytic triad that is distinct from lipase. We, therefore, hypothesized that the family VIII carboxylesterase may exhibit (S)-enantioselectivity toward sec-alcohols similar to (S)-selective serine protease, whose catalytic triad is also spatially arrayed as its mirror image. In this study, a homologous enzyme (carboxylesterase from Proteobacteria bacterium SG_bin9, PBE) of a known family VIII carboxylesterase (pdb code: 4IVK) was prepared, which showed not only moderate (S)-selectivity toward sec-alcohols such as 3-butyn-2-ol and 1-phenylethyl alcohol but also (R)-selectivity toward particular sec-alcohols among the substrates explored. Furthermore, the (S)-selectivity of PBE has been significantly improved by rational redesign based on molecular modeling. Molecular modeling identified a binding pocket composed of Ser381, Ala383, and Arg408 for the methyl substituent of (R)-1-phenylethyl acetate and suggested that larger residues may increase the enantioselectivity by interfering with the binding of the slow-reacting enantiomer. As predicted, substituting Ser381with larger residues (Phe, Tyr, and Trp) significantly improved the (S)-selectivity of PBE toward all sec-alcohols explored, even the substrates toward which the wild-type PBE exhibits (R)-selectivity. For instance, the enantioselectivity toward 3-butyn-2-ol and 1-phenylethyl alcohol was improved from E = 5.5 and 36.1 to E = 2001 and 882, respectively, by single mutagenesis (S381F).
One-pot kinetic resolution-Mitsunobu reaction to access optically pure compounds, using silver salts in the substitution protocol
Raval, Hiten B.,Bedekar, Ashutosh V.
, p. 21238 - 21243 (2020/12/31)
A practical method is developed to access chiral arylalkyl carbinols with a high yield from racemic alcohols. A one-pot enzyme mediated Kinetic Resolution followed by Mitsunobu esterification of the unreacted enantiomer of alcohol with metal acetate results in a nearly complete formation of chiral acetate. Substitution with AgOAc was found to be the most efficient, and the use of sub stoichiometric amounts of AgNO3 and excess of NaOAc affords comparable results; the protocol was further extended to introduce azide as a nucleophile.
