868-72-4Relevant articles and documents
Synthetic method of alicyclic diester
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Paragraph 0026; 0028; 0039; 0040, (2018/11/03)
The invention discloses a synthetic method of alicyclic diester. The synthetic method comprises the following steps: enabling diacid comprising a multi-carbon lipid chain end group or diester containing a multi-carbon lipid chain end group to react with a first halogenation reagent, after the reaction is completed, adding a second halogenation reagent into a reaction product, after the reaction iscompleted, re-esterifying, and obtaining the di-ester of di-halogenation; adding the di-ester of the di-halogenation into an organic solvent, adding alkali to perform the reaction, after the reactionis completed, adding acid to perform the neutralization, and obtaining annular di-ester; and performing the reduction reaction for the annular di-ester, and obtaining the alicyclic diester. By adopting the synthetic method, a novel reaction path is developed, and the direct-chain end-group diacid or diester is used as a raw material to prepare the alicyclic diester by virtue of bromination reaction, ring-closing reaction and the reduction reaction. The initial raw material is low in cost, the process is simple, the reaction condition requirement is low, the safety is good, the product yield and purity are high, and the mass production is easy to realize. Moreover, the diester of a three-membered ring to an eighteen-membered ring can be prepared by utilizing the synthetic method of the invention.
A mechanochemical approach to access the proline-proline diketopiperazine framework
Pétry, Nicolas,Benakki, Hafid,Clot, Eric,Retailleau, Pascal,Guenoun, Farhate,Asserar, Fatima,Sekkat, Chakib,Métro, Thomas-Xavier,Martinez, Jean,Lamaty, Frédéric
, p. 2169 - 2178 (2017/11/16)
Ball milling was exploited to prepare a substituted proline building block by mechanochemical nucleophilic substitution. Subsequently, the mechanocoupling of hindered proline amino acid derivatives was developed to provide proline-proline dipeptides under solvent-free conditions. A deprotection-cyclization sequence yielded the corresponding diketopiperazines that were obtained with a high stereoselectivity which could be explained by DFT calculations. Using this method, an enantiopure disubstituted Pro-Pro diketopiperazine was synthesized in 4 steps, making 5 new bonds using a ball mill.
Biomimetic Design Results in a Potent Allosteric Inhibitor of Dihydrodipicolinate Synthase from Campylobacter jejuni
Skovpen, Yulia V.,Conly, Cuylar J. T.,Sanders, David A. R.,Palmer, David R. J.
supporting information, p. 2014 - 2020 (2016/03/01)
Dihydrodipicolinate synthase (DHDPS), an enzyme required for bacterial peptidoglycan biosynthesis, catalyzes the condensation of pyruvate and β-aspartate semialdehyde (ASA) to form a cyclic product which dehydrates to form dihydrodipicolinate. DHDPS has, for several years, been considered a putative target for novel antibiotics. We have designed the first potent inhibitor of this enzyme by mimicking its natural allosteric regulation by lysine, and obtained a crystal structure of the protein-inhibitor complex at 2.2 ? resolution. This novel inhibitor, which we named 'bislysine', resembles two lysine molecules linked by an ethylene bridge between the α-carbon atoms. Bislysine is a mixed partial inhibitor with respect to the first substrate, pyruvate, and a noncompetitive partial inhibitor with respect to ASA, and binds to all forms of the enzyme with a Ki near 200 nM, more than 300 times more tightly than lysine. Hill plots show that the inhibition is cooperative, indicating that the allosteric sites are not independent despite being located on opposite sides of the protein tetramer, separated by approximately 50 ?. A mutant enzyme resistant to lysine inhibition, Y110F, is strongly inhibited by this novel inhibitor, suggesting this may be a promising strategy for antibiotic development.
Switching and Conformational Fixation of Amides Through Proximate Positive Charges
Bartuschat, Amelie L.,Wicht, Karina,Heinrich, Markus R.
supporting information, p. 10294 - 10298 (2015/09/01)
Tertiary amides, which usually occur as cis/trans mixtures, can be effectively shifted to the cis conformation by placing a positive charge in close proximity to the amide carbonyl. This effect was used to prepare cis-configured prolyl amides and to facilitate a strongly rotamer-dependent radical cyclization. Taking charge of conformation: Tertiary amides, which usually occur as cis/trans mixtures, can be effectively shifted to the cis conformation by placing a positive charge in close proximity to the amide carbonyl. This effect was used to prepare cis-configured prolyl amides and to facilitate a strongly rotamer-dependent radical cyclization.
Explorations into the potential of chiral sulfonium reagents to effect asymmetric halonium additions to isolated alkenes
Brucks, Alexandria P.,Treitler, Daniel S.,Liu, Shu-An,Snyder, Scott A.
, p. 1886 - 1898 (2013/07/26)
While methods for the racemic dihalogenation and halohydroxylation of alkenes have been known for decades, enantioselective variants of these processes remain elusive. Initial attempts were made to overcome this long-standing challenge by exploring the potential of chiral, crystalline, sulfur-derived halonium reagents to accomplish the asymmetric dichlorination and iodohydroxylation of 1,2-dihydronaphthalene. Asymmetric dichlorination of this substrate was achieved in 57% yield and 14% enantiomeric excess (ee), but asymmetric iodohydroxylation was much more successful, giving 67% yield and 63% ee. Thorough studies were made of these processes, including investigation of various chiral sulfide derivatives, their substrate scopes, and the reaction conditions. Georg Thieme Verlag Stuttgart · New York.
New β-phospholactam as a carbapenem transition state analog: Synthesis of a broad-spectrum inhibitor of metallo-β-lactamases
Yang, Ke-Wu,Feng, Lei,Yang, Shao-Kang,Aitha, Mahesh,Lacuran, Alecander E.,Oelschlaeger, Peter,Crowder, Michael W.
supporting information, p. 5855 - 5859 (2013/10/22)
In an effort to test whether a transition state analog is an inhibitor of the metallo-β-lactamases, a phospholactam analog of carbapenem has been synthesized and characterized. The phospholactam 1 proved to be a weak, time-dependent inhibitor of IMP-1 (70%), CcrA (70%), L1 (70%), NDM-1 (53%), and Bla2 (94%) at an inhibitor concentration of 100 μM. The phospholactam 1 activated ImiS and BcII at the same concentration. Docking studies were used to explain binding and to offer suggestions for modifications to the phospholactam scaffold to improve binding affinities.
Visible-light-triggered release of nitric oxide from N-pyramidal nitrosamines
Karaki, Fumika,Kabasawa, Yoji,Yanagimoto, Takahiro,Umeda, Nobuhiro,Firman,Urano, Yasuteru,Nagano, Tetsuo,Otani, Yuko,Ohwada, Tomohiko
experimental part, p. 1127 - 1141 (2012/03/26)
Although many organic/inorganic compounds that release nitric oxide (NO) upon photoirradiation (phototriggered caged-NOs) have been reported, their photoabsorption wavelengths mostly lie in the UV region, because X - NO bonds (X=heteroatom and metal) generally have rather strong π-bond character. Thus, it is intrinsically difficult to generate organic compounds that release NO under visible light irradiation. Herein, the structures and properties of N-pyramidal nitrosamine derivatives of 7-azabicyclo[2.2.1]heptanes that release NO under visible light irradiation are described. Bathochromic shifts of the absorptions of these nitrosamines, attributed to HOMO (n)-LUMO (π*) transitions associated with the nonplanar structure of the N - NO moiety, enable the molecules to absorb visible light, which results in N - NO bond cleavage. Thus, these compounds are innate organic caged-NOs that are uncaged by visible light. A visible difference: Nitrosamine derivatives of 7-azabicyclo[2.2.1]heptanes undergo N - NO bond cleavage upon exposure to visible light at wavelengths longer than 420a nm, thereby releasing NO. Bathochromic shifts of the absorptions of these nitrosamines are attributed to HOMO (n)-LUMO (π*) transitions associated with the nonplanar structure of the N - NO moiety (see figure). Copyright
Enolates of 2-isothiocyanatocarboxylic esters: Synthesis of thiazolo[5,4-d]-thiazole derivatives and 2-thioxo-1,3-thiazolidine-4- carboxylates
Cie, Dariusz,Kalinowska-Tucik, Justyna
scheme or table, p. 1736 - 1744 (2012/07/28)
An oxidative dimerization of titanium(IV) enolates derived from menthyl esters of 2-isothiocarboxylic acids leads to radical coupling followed by cyclization. This cascade reaction gives thiazolo[5,4-d]thiazole derivatives as pure enantiomers. Under simil
Structure-mechanochemical activity relationships for cyclobutane mechanophores
Kryger, Matthew J.,Munaretto, Alexander M.,Moore, Jeffrey S.
supporting information; experimental part, p. 18992 - 18998 (2012/02/05)
Ultrasound activation of mechanophores embedded in polymer backbones has been extensively studied of late as a method for realizing chemical reactions using force. To date, however, there have been few attempts at systematically investigating the effects of mechanophore structure upon rates of activation by an acoustic field. Herein, we develop a method for comparing the relative reactivities of various cyclobutane mechanophores. Through the synthesis and ultrasonic irradiation of a molecular weight series of poly(methyl acrylate) polymers in which each macromolecule has a single chain-centered mechanophore, we find measurable and statistically significant shifts in molecular weight thresholds for mechanochemical activation that depend on the structure of the mechanophore. We also show that calculations based on the constrained geometries simulate external force method reliably predict the trends in mechanophore reactivity. These straightforward calculations and the experimental methods described herein may be useful in guiding the design and the development of new mechanophores for targeted applications.
Synthesis of new tetrazole-substituted pyroaminoadipic and pipecolic acid derivatives
Lenda, Fatimazohra,Guenoun, Farhate,Tazi, Bouchra,Iarbi, Najib Ben,Allouchi, Hassan,Martinez, Jean,Lamaty, Frederic
, p. 326 - 333 (2007/10/03)
Racemic 5-aryl- and 5-(arylmethyl)tetrazolyl-substituted pyroaminoadipic and pipecolic acid derivatives were diastereoselectively synthesized from dimethyl meso-2,5-dibromoadipate (1) in good yields under mild reaction conditions. The key step of this reaction sequence is the selective N2-alkylation of 5-substituted tetrazoles with 1. The reactive 2-bromo-5-tetrazolyladipate derivatives 2a-g were generated and treated with sodium azide, followed by Pd/C-catalyzed hydrogenation, to provide lactams 4a-g. The chemoselective reduction of the amide carbonyl group of 4a-g with BH 3, followed by acid hydrolysis, provided 5-tetrazolylpipecolic acids in racemic form. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
