10065-72-2Relevant academic research and scientific papers
Accelerated tert-butyloxycarbonyl deprotection of amines in microdroplets produced by a pneumatic spray
Fedick, Patrick W.,Bain, Ryan M.,Bain, Kinsey,Mehari, Tsdale F.,Cooks, R. Graham
, p. 98 - 103 (2018)
Protection and deprotection of organic compounds in multistep reactions using functional groups such as tert-butoxycarbonyl (Boc), is widely performed in synthetic organic chemistry. Reaction rate acceleration studies in spray-based ionization methods (electrosonic spray, paper spray, nanospray) have become increasingly common. Here, we demonstrate reaction rate acceleration of Boc deprotection using easy ambient sonic-spray ionization (EASI), a pneumatic technique which does not involve an applied voltage, in a teaching laboratory setting. The goal of this laboratory exercise was to explore acceleration in a previously unexplored spray-based reaction, while emphasizing in a pedagogic setting the importance of protecting groups for multistep synthesis. Rate acceleration factors of more than an order of magnitude were observed in the uncharged micron-sized droplets generated by EASI. The effect of reaction conditions on reaction acceleration was examined including changes in the type of acid, reagent concentration ratios and syringe pump flow rates. Student knowledge was assessed by pre-laboratory assignments, post-laboratory reports and oral interviews.
Synthesis, insecticidal activities and SAR studies of novel anthranilic diamides containing trifluoroethoxyl substituent and chiral amino acid moieties
Zhou, Shaa,Zhou, Sha,Xie, Yongtao,Meng, Xiangde,Wang, Baolei,Xiong, Lixia,Yang, Na,Li, Zhengming
, p. 1254 - 1256 (2018)
Ryanodine receptors (RyRs) activator has become one class of popular insecticide because of its unique mode of action. In order to find more new RyRs activators as insecticidal agents, a series of 18 novel chiral anthranilic diamides were designed by introducing the D-alanine acid and D-serine acid esters as well as trifluoroethoxyl group into the anthranilic diamide skeleton and synthesized successfully based on anthranilic diamide and FKI-1033 structures. The structures of the title compounds Ia–i and IIa–i were confirmed by melting points, 1H NMR, 13C NMR, elemental analysis and specific optical rotation analysis. The preliminary bioassay results indicated that most of the title compounds exhibited considerable larvicidal activities against oriental armyworm at 10 mg/L, especially Ib, Ie and IIh showed remarkable insecticidal activities at 0.5 mg/L. The larvicidal activity against diamondback moth of Ia and IId were 80% and 90% respectively at 0.0001 mg/L, which was similar to that of chlorantraniliprole. The relationship between structure and insecticidal activity was analyzed to reveal a possible co-regulated effect of the chiral amino acid ester, halogen atom or cyano group, and trifluoroethyloxyl group of the skeleton structures of the title compounds, which will provide useful information for guiding the design and discovery of new RyRs activators and insecticidal agrochemicals.
In situ deprotection and incorporation of unnatural amino acids during cell-free protein synthesis
Arthur, Isaac N.,Hennessy, James E.,Padmakshan, Dharshana,Stigers, Dannon J.,Lesturgez, Stéphanie,Fraser, Samuel A.,Liutkus, Mantas,Otting, Gottfried,Oakeshott, John G.,Easton, Christopher J.
, p. 6824 - 6830 (2013)
The S30 extract from E. coli BL21 Star (DE3) used for cell-free protein synthesis removes a wide range of α-amino acid protecting groups by cleaving α-carboxyl hydrazides; methyl, benzyl, tert-butyl, and adamantyl esters; tert-butyl and adamantyl carboxamides; α-amino form-, acet-, trifluoroacet-, and benzamides and sidechain hydrazides and esters. The free amino acids are produced and incorporated into a protein under standard conditions. This approach allows the deprotection of amino acids to be carried out in situ to avoid separate processing steps. The advantages of this approach are demonstrated by the efficient incorporation of the chemically intractable (S)-4-fluoroleucine, (S)-4,5- dehydroleucine, and (2S,3R)-4-chlorovaline into a protein through the direct use of their respective precursors, namely, (S)-4-fluoroleucine hydrazide, (S)-4,5-dehydroleucine hydrazide, and (2S,3R)-4-chlorovaline methyl ester. These results also show that the fluoroand dehydroleucine and the chlorovaline are incorporated into a protein by the normal biosynthetic machinery as substitutes for leucine and isoleucine, respectively. Copyright
Instability of Amide Bond Comprising the 2-Aminotropone Moiety: Cleavable under Mild Acidic Conditions
Balachandra, Chenikkayala,Sharma, Nagendra K.
, p. 3948 - 3951 (2015)
An unusual hydrolysis/solvolysis of the classical acyclic amide bond, derived from N-troponylaminoethylglycine (Traeg) and α-amino acids, is described under mild acidic conditions. The reactivity of this amide bond is possibly owed to the protonation of the troponyl carbonyl functional group. The results suggest that the Traeg amino acid is a potential candidate for protecting and caging of the amine functional group of bioactive molecules via a cleavable amide bond.
Photochemical desulfurization of L-cysteine derivatives
Gonzalez, Asensio,Valencia, Gregorio
, p. 2761 - 2764 (1998)
Thiol groups can be reductively eliminated at room temperature by a photochemical method which makes use of triethylboron, triethylphosphite and visible light. Thus, after treating L-Cys 1a, D-Pen 1b, L-Cys-OMe 1c and glutathione (γ-L-Glu-L-Cys-Gly) 3, the corresponding desulfurized compounds L-Ala 2a, D-Val 2b, L-Ala-OMe 2c and γ-L-Glu-L-Ala-Gly 4, respectively, are prepared in high yields and with retention of configuration.
A New Set of Isoreticular, Homochiral Metal-Organic Frameworks with ucp Topology
Sartor, Michael,Stein, Timo,Hoffmann, Frank,Fr?ba, Michael
, p. 519 - 528 (2016)
A new isoreticular series of metal-organic frameworks, called UHM-25 (UHM: University of Hamburg Materials), based on the copper paddle wheel motif and a novel set of homochiral linkers has been synthesized. Starting from amino acids available from the chiral pool a synthesis procedure was established that allows a straightforward, multigram scale synthesis of homochiral linkers in 4-5 steps. These linkers carry substituents that have been proven useful in stereoselective organic chemistry, such as the Evans auxiliary or chiral amino alcohols. The resulting MOFs only differ in the chiral moiety provided by the amino acid starting material. The structure of UHM-25 is composed of cuboctahedral cages of Cu2 paddle wheel motifs connected by the isophthalate moieties of the linker. These cages are linked via the bent backbone of the linker resulting in a primitive cubic arrangement, giving rise to the rare underlying (3,4)-c binodal net ucp. MOFs of the UHM-25 series show surface areas up to SBET = 1900 m2/g. Postsynthetic modification reactions with excellent conversion rates confirmed the accessibility to the chiral groups. Furthermore, UHM-25-Pro bearing a prolinol functionality was used in a self-directed, enantioselective aldol addition of acetaldehyde, demonstrating the potential of the UHM-25 series with regard to heterogeneous, stereoselective catalysis.
Stereochemical studies of adrenergic drugs. Optically active derivatives of imidazolines
Miller,Hsu,Ruffolo Jr.,Patil
, p. 1382 - 1384 (1976)
The synthesis of (R) (+) 4 methyl 2 (1 naphthylmethyl)imidazoline hydrochloride (2) and (S) (-) 4 methyl 2 (1 naphthylmethyl)imidazoline hydrochloride (3) is presented. The synthesis involves the preparation of (R) (+) and (S) (-) 1,2 diaminopropane dihydrochloride and then allowing the appropriate diaminopropane to react with ethyl 1 naphthyliminoacetate hydrochloride in the presence of triethylamine. The parent compound, naphazoline, is a potent α adrenoreceptor agonist (-log ED50 = 7.22), whereas the methylated derivatives, 2 and 3, were moderately potent antagonists (pA2 = 5.6 and 5.8, respectively) of the α adrenoreceptor. Compounds 2 and 3 also produced blockade of the response to histamine on the rabbit aorta, but at concentrations approximately 20 times higher than necessary to produce equal blockade of the α adrenoreceptor.
Crystallographic insight-guided nanoarchitectonics and conductivity modulation of an n-type organic semiconductor through peptide conjugation
Pandeeswar,Khare, Harshavardhan,Ramakumar, Suryanarayanarao,Govindaraju
, p. 8315 - 8318 (2015)
Crystallographic insight-guided nanoarchitectonics of peptide-conjugated naphthalene diimide (NDI) is described. In a bio-inspired approach, non-proteinogenic α-amino isobutyric acid (Aib)- and alanine (Ala)-derived peptides orchestrated the 1D achiral and 2D chiral molecular ordering of NDI, respectively, which resulted in modulation of nanoscale morphology, chiroptical and conductivity properties.
N-acylated alanine methyl esters (NAMEs) from Roseovarius tolerans, structural analogs of quorum-sensing autoinducers, N-acylhomoserine lactones
Bruns, Hilke,Thiel, Verena,Voget, Sonja,Patzelt, Diana,Daniel, Rolf,Wagner-Doebler, Irene,Schulz, Stefan
, p. 1559 - 1573 (2013)
The Roseobacter clade is one of the most important bacteria group living in the ocean. Liquid cultures of Roseovarius tolerans EL 164 were investigated for the production of autoinducers such as N-acylhomoserine lactones (AHLs) and other secondary metabolites. The XAD extracts were analyzed by GC/MS. Two AHLs, Z7-C14: 1-homoserine lactone (HSL) and C15: 1-HSL, were identified. Additionally, the extract contained five compounds with molecular-ion peaks at m/z 104, 145, and 158, thus exhibiting mass spectra similar to those of AHLs with corresponding peaks at m/z 102, 143, and 156. Isolation of the main compound by column chromatography, NMR analysis, dimethyl disulfide derivatization for the determination of the location of the CiC bond and finally synthesis of the compound with the proposed structure confirmed the compound to be (Z)-N-(hexadec-9-enoyl)alanine methyl ester. Four additional minor compounds were identified as C14: 0-, C15: 0-, C16: 0-, and C17: 1-N-acylated alanine methyl esters (NAMEs). All NAMEs have not been described from natural sources before. A BLASTp search showed the presence of AHL-producing luxI genes, but no homologous genes potentially responsible for the structurally closely related NAMEs were found. The involvement of the NAMEs in chemical communication processes of the bacteria is discussed. Copyright
Chiral iminoesters derived from d-glyceraldehyde in [3+2] cycloaddition reactions. Asymmetric synthesis of a key intermediate in the synthesis of neuramidinase inhibitors
Galvez, Jose A.,Diaz-De-Villegas, Maria D.,Alias, Miriam,Badorrey, Ramon
, p. 11404 - 11413 (2013)
Silver-catalyzed endo-selective and copper-catalyzed exo-selective asymmetric [3 + 2] cycloadditions of acrylates to chiral iminoesters derived from d-glyceraldehyde have been investigated. The reaction diastereoselectively provides highly functionalized pyrrolidines. This approach was used to develop the first asymmetric synthesis of a key intermediate in the synthesis of pyrrolidine influenza neuramidinase inhibitors.
