116129-92-1Relevant academic research and scientific papers
Enantio- and diastereoselective hydrogenation via dynamic kinetic resolution by a cationic iridium complex in the synthesis of β-hydroxy-α-amino acid esters
Makino, Kazuishi,Iwasaki, Masamichi,Hamada, Yasumasa
, p. 4573 - 4576 (2006)
Anti-selective asymmetric hydrogenation of α-amino-β-keto esters via dynamic kinetic resolution under low hydrogen pressure has been achieved by an easily-handled cationic iridium complex with tetrakis[3,5- bis(trifluoromethyl)phenyl]borate (BARF) as a co
GLP-1 RECEPTOR MODULATORS
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, (2016/06/28)
Compounds are provided that modulate the glucagon-like peptide 1 (GLP-1) receptor, as well as methods of their synthesis, and methods of their therapeutic and/or prophylactic use. Such compounds can act as modulators or potentiators of GLP-1 receptor on their own, or with incretin peptides such as GLP-1(7-36) and GLP-1(9-36), or with peptide-based therapies, such as exenatide and liraglutide, and have the following general structure (where "^^^^" represents either or both the R and S form of the compound) (I) where A, B, C, Y1, Y2, Z, R1, R2, R3, R4, R5, W1, n, p and q are as defined herein.
A versatile approach to noncoded β-hydroxy-α-amino esters and α-amino acids/esters from morita-baylis-hillman adducts
Ullah, Hamid,Ferreira, Andr V.,Bendassolli, Jos A.,Rodrigues, Manoel T.,Formiga, Andr Luiz B.,Coelho, Fernando
, p. 113 - 123 (2015/02/02)
A simple and straightforward approach to the diastereoselective synthesis of noncoded β-hydroxy-α-amino esters from Morita-Baylis-Hillman (MBH) adducts is described. The strategy is based on a one-pot sequence involving an oxidative cleavage of the double bond of silylated Morita-Baylis-Hillman adducts, followed by the reaction with hydroxylamine hydrochloride/pyridine to form oximes. The stereoselective reduction of the oximes with the mixture MoCl5·nH2O/NaBH3CN led to the corresponding anti-β-hydroxy-α-amino esters in four steps in good overall yield and with diastereoselectivity higher than 95%. A slight modification of the synthetic approach has allowed for the racemic synthesis of a set of noncoded α-amino esters/acids and DOPA
Asymmetric synthesis of 2,4,5-trisubstituted Δ2- thiazolines
Bengtsson, Christoffer,Nelander, Hanna,Almqvist, Fredrik
, p. 9916 - 9922 (2013/08/23)
Δ2-Thiazolines are interesting heterocycles that display a wide variety of biological characteristics. They are also common in chiral ligands used for asymmetric syntheses and as synthetic intermediates. Herein, we present asymmetric routes to
Enantioselective synthesis of anti-β-hydroxy-α-amido esters by asymmetric transfer hydrogenation in emulsions
Seashore-Ludlow, Brinton,Villo, Piret,Somfai, Peter
, p. 7219 - 7223 (2012/07/13)
Herein, we present two methods for an asymmetric transfer hydrogenation through the dynamic kinetic resolution of α-amido-β-ketoesters. These procedures yield the corresponding anti-β-hydroxy-α-amido esters in good yields and with good diastereo- and enantioselectivities. First, the scope of the reduction of α-amido-β-ketoesters by using triethylammonium formate azeotrope is examined. Then, an emulsion technology with sodium formate is explored, which allows for broader substrate scope, faster reaction times, and lower catalyst loading. Furthermore, these reactions are operationally simple and can be set up in air.
Enantioselective synthesis of anti -β-hydroxy-α-amido esters via transfer hydrogenation
Seashore-Ludlow, Brinton,Villo, Piret,Haecker, Christine,Somfai, Peter
supporting information; experimental part, p. 5274 - 5277 (2011/01/12)
The asymmetric transfer hydrogenation of α-amido-β-keto esters to provide the corresponding anti-β-hydroxy-α-amido esters in good to excellent yields, diastereoselectivity, and enantioselectivity is reported. The procedure is operationally simple, and delicate handling of the catalyst is not necessary.
Addition of azomethine ylides to aldehydes: Mechanistic dichotomy of differentially substituted α-imino esters
Seashore-Ludlow, Brinton,Torssell, Staffan,Somfai, Peter
scheme or table, p. 3927 - 3933 (2010/09/18)
The formal 1,3-dipolar cycloaddition of azomethine ylides and aldehydes is explored, as hydrolysis of the resulting oxazolidine product gives facile access to valuable syn-β-arylβ-hydroxy-α-amino esters. The use of using benzaldehydederived imines as the ylide precursor results in 1,3-dipolar cycloaddition with high conversions but low diastereoselec-tivity. In contrast, the employment of benzophenone-derived imines as the ylide precursor results in an aldol reaction, which gives the intermediate oxazolidine in high diastereoselectivity and requires a weak acid catalyst to achieve higher conversions.
Diastereo- and enantioselective hydrogenation of α-amino-β-keto ester hydrochlorides catalyzed by an iridium complex with MeO-BIPHEP and NaBArF: Catalytic cycle and five-membered chelation mechanism of asymmetric hydrogenation
Maeda, Tsukuru,Makino, Kazuishi,Iwasaki, Masamichi,Hamada, Yasumasa
supporting information; experimental part, p. 11954 - 11962 (2011/01/12)
The development of Ir-catalyzed asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides is described. This reaction proceeds through a dynamic kinetic resolution to produce anti-β-hydroxy- α-amino acid esters in a high diastereo- and enantioselective manner. Mechanistic studies have revealed that this unique asymmetric hydrogenation proceeds through reduction of the ketone moiety via the five-membered transition state involving the chelation between the oxygen of the ketone and the nitrogen of the amine function. The relationship studies between the hydrogen pressure and the stereoselectivity have disclosed two mechanisms dependent on hydrogen pressure. Under low hydrogen pressure (15 atm), the reaction rate proportionally increased with the hydrogen pressure. However, under the high hydrogen conditions, the reaction rate exponentially accelerated along with the increasing hydrogen pressure, which suggests the participation of two or more of hydrogen atoms. Apply some pressure: The Ir-catalyzed asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides proceeds through a dynamic kinetic resolution to produce anti-β-hydroxy-α-amino acid esters in a high diastereo- and enantioselective manner (see scheme). Mechanistic studies revealed that this unique asymmetric hydrogenation proceeds through reduction of the ketone moiety via the five-membered transition state.
Catalytic asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides using homogeneous chiral nickel-bisphosphine complexes through DKR
Hamada, Yasumasa,Koseki, Yu,Fujii, Takefumi,Maeda, Tsukuru,Hibino, Takuya,Makino, Kazuishi
scheme or table, p. 6206 - 6208 (2009/05/06)
Homogeneous chiral nickel-bisphosphine complexes catalyze the asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides through dynamic kinetic resolution to efficiently afford anti-β-hydroxy-α-amino esters with high diastereo- and enantioselectivit
Stereoselective synthesis of β-hydroxyphenylalanines using imino 1,2-Wittig rearrangement of hydroximates
Miyata, Okiko,Asai, Hiroshi,Naito, Takeaki
, p. 355 - 360 (2007/10/03)
The imino 1,2-Wittig rearrangement of hydroximates containing a furan ring provides a novel method for the synthesis of β-hydroxy-α-amino acids. Upon treatment with LDA, hydroximates smoothly underwent the rearrangement to give Z-2-hydroxyoxime ethers in good yield, which were converted into both cis- and trans-oxazolidinones with high stereoselectivity. The cis- and trans-oxazolidinones were stereoselectively converted into erythro- and thereo-β-hydroxypheny lalanines, respectively, via the oxidative cleavage of a furan ring, ring-opening of oxazolidinone, and deprotection.
