- Divergent Synthesis of Enantioenriched β-Functional Amines via Desymmetrization of meso-Aziridines with Isocyanides
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A highly enantioselective ring-opening desymmetrization of meso-aziridines with isocyanides was achieved in the presence of a chiral N,N′-dioxide/Mg(OTf)2 complex. The in situ generated chiral 1,4-zwitterionic intermediates were successfully trapped by intramolecular oxygen- and carbon-based nucleophiles or exogenous H2O and TMSN3, enabling a collective synthesis of various chiral vicinal amino-oxazoles, spiroindolines, β-amino amides, and tetrazole derivative in moderate to high yields with excellent enantioselectivities.
- Li, Xiangqiang,Xiong, Qian,Guan, Mingming,Dong, Shunxi,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 6096 - 6101
(2019/08/20)
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- Effector enhanced enantioselective hydroformylation
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In this communication, we report rhodium DIMPhos complexes with an integrated DIM-receptor that can bind carboxylate containing effectors and their application in the rhodium catalyzed hydroformylation reaction. The binding of chiral effectors in non-chiral [Rh(DIMPhos)] catalysts does not lead to enantioselective hydroformylation, but the binding of either achiral or chiral effectors can significantly enhance the enantioselectivity induced by the chiral Rh-metal complexes. For example, the supramolecular complex [Rh]/[1S?L3] displays high regio- and enantioselectivity in the hydroformylation of vinyl acetate (72% ee, and b/l >99), whereas in absence of this effector the ee is around 17%.
- Bai, Shao-Tao,Kluwer, Alexander M.,Reek, Joost N. H.
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supporting information
p. 14151 - 14154
(2019/12/02)
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- Formyloxyacetoxyphenylmethane as an N-Formylating Reagent for Amines, Amino Acids, and Peptides
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Formyloxyacetoxyphenylmethane is a stable, water-tolerant, N-formylating reagent for primary and secondary amines that can be used under solvent-free conditions at room temperature to prepare a range of N-formamides, N-formylanilines, N-formyl-α-amino acids, N-formylpeptides, and an isocyanide.
- Chapman, Robert S. L.,Lawrence, Ruth,Williams, Jonathan M. J.,Bull, Steven D.
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supporting information
p. 4908 - 4911
(2017/09/23)
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- GRAMICIDIN A MUTANTS THAT FUNCTION AS ANTIBIOTICS WITH IMPROVED SOLUBILITY AND REDUCED TOXICITY
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Described herein are antimicrobial peptides for use in pharmaceutical antibiotic compositions and methods of use thereof. These antimicrobial peptides are Gramicidin A (gA) peptide analogs that, in addition to having potent anti-microbial activity, have greatly increased solubility and significantly reduced toxicity in comparison to the wild-type Gramicidin A peptide.
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Paragraph 0285
(2015/09/23)
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- ANTIFOULING AGENT FOR UNDERWATER ADHERING ORGANISMS HAVING AMINO ACID ISONITRILE SKELETON
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PROBLEM TO BE SOLVED: To provide a novel antifouling agent for underwater adhering organisms having excellent characteristics compared with well-known antifouling agents. SOLUTION: An antifouling agent for underwater adhering organisms comprises a compound represented by formula (I) or salt thereof, or solvate thereof, as an active ingredient. COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0126
(2016/11/14)
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- Thioester-isocyanides: Versatile reagents for the synthesis of cycle-tail peptides
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A novel class of reagents, thioester isocyanides, have been prepared and applied in the synthesis of peptide macrocycles. The isocyanide part of the molecule is deployed in a multicomponent macrocyclization step. This step is followed by chemoselective peptide ligation at the thioester part of the macrocycle. Our method can now be used for rapid assembly and evaluation of cycle-tail peptides. The Royal Society of Chemistry 2012.
- Rotstein, Benjamin H.,Winternheimer, David J.,Yin, Lois M.,Deber, Charles M.,Yudin, Andrei K.
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supporting information; experimental part
p. 3775 - 3777
(2012/06/15)
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- Nano rod-shaped and reusable basic Al2O3 catalyst for N-formylation of amines under solvent-free conditions: A novel, practical and convenient 'NOSE' approach
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An expeditious, simple, highly efficient, practical and green protocol for the N-formylation of alkyl/aryl amines and indole derivatives catalyzed by novel nano rod-shaped basic Al2O3 under solvent-free conditions has been developed. The catalyst is efficiently recycled up to the 5th run, an important point in the domain of green chemistry. The methodology provides cleaner conversion, shorter reaction times and high selectivity which makes the protocol attractive. The Royal Society of Chemistry 2012.
- Das, Vijay Kumar,Devi, Rashmi Rekha,Raul, Prasanta Kumar,Thakur, Ashim Jyoti
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supporting information; experimental part
p. 847 - 854
(2012/04/23)
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- "Cofactor"-controlled enantioselective catalysis
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We report an achiral bisphosphine rhodium complex equipped with a binding site for the recognition of chiral anion guests. Upon binding small chiral guests-cofactors-the rhodium complex becomes chiral and can thus be used for asymmetric catalysis. Screening of a library of cofactors revealed that the best cofactors lead to hydrogenation catalysts that form the products with high enantioselectivity (ee?s up to 99%). Interestingly, a competition experiment shows that even in a mixture of 12 cofactors high ee is obtained, indicating that the complex based on the best cofactor dominates the catalysis.
- Dydio, Pawel,Rubay, Christophe,Gadzikwa, Tendai,Lutz, Martin,Reek, Joost N. H.
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supporting information; experimental part
p. 17176 - 17179
(2011/12/13)
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- Synthesis of chiral pentacyclo-undecane ligands and their use in the enantioselective alkylation of benzaldehyde with diethylzinc
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The synthesis of a new class chiral cage annulated bidentate ligands is reported. The ability of the chiral amino alcohols to catalyse the enantioselective addition of diethyl zinc to benzaldehyde was investigated. The cage annulated amino alcohols have C1 symmetry and showed poor to good enantioselectivity with high chemical yields. The system could be utilised as a versatile probe into the reaction mechanism. The synthesis of a new class of chiral pentacycloundecane cage annulated bidentate ligands is reported. This class of ligands can be used in many reactions that are catalysed by amino alcohol ligands. The ability of the chiral ligands to asymmetrically catalyse the reaction between diethylzinc and benzaldehyde was investigated. The cage annulated bidentate ligands have C1 symmetry and showed poor to good enantioselectivity with high yields compared to previous systems reported using other amino alcohol ligands. An important conclusion from the results is that both ligands should be involved in the mechanism as the bidentate ligands gives much improved enantioselectivity when compared with a single chiral source molecule. This system could be utilised as a versatile probe for examining the reaction mechanism.
- Boyle, Grant A.,Govender, Thavendran,Kruger, Hendrik G.,Maguire, Glenn E.M.
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p. 2661 - 2666
(2007/10/03)
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- Remote binding energy in antibody catalysis: Studies of a catalytically unoptimized specificity pocket
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Binding interactions remote from the hydrolytic reaction center have been probed with substrate and phosphonate transition state analogues to understand how these types of interactions are used to promote catalysis in the 17E8 system. We find that the hapten-generated recogniton pocket in 17E8 has properties that are analogous to those of specificity pockets in enzymes. We have also found that there are specific requirements to form catalytically productive interactions between the side chain and the recognition pocket including conformation, size, and geometry. An additional requirement includes favorable simultaneous interactions between the side chain and binding pocket along with favorable interactions with the oxyanion hole. The 17E8 side chain recognition pocket seems to be less catalytically efficient than analogous pockets in enzymatic systems. The apparent binding energy gained from the methylene-pocket interactions in the 17E8 system is significantly smaller than those observed in natural enzymes. Furthermore, 17E8 does not use specific interactions in the recognition pocket to significantly affect catalytic turnover (kcat) which is thought to be a trait of an unoptimized catalyst. Analysis of the crystal structure of the 17E8·hapten complex has allowed for the identification of differences between the active sites of 17E8 and several proteases. The identified differences give insight to the sources of the inefficient use of binding energy.
- Wade, Herschel,Scanlan, Thomas S.
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p. 1434 - 1443
(2007/10/03)
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- Preparation of alpha-formylamino nitriles
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A process for preparing α-formylamino nitriles of the formula Ia STR1 and Ib STR2 where R1, R2, R3 and R4 are identical or different and each is hydrogen or unsubstituted or substituted, with substituents which are inert under the reaction conditions, aliphatic or heteroaliphatic radicals with 1 to 10, cycloaliphatic or heterocycloaliphatic radicals with 3 to 6, araliphatic radicals with 7 to 12, heteroaraliphatic radicals with 4 to 12, aromatic radicals with 6 to 10 or heteroarometic radicals with 3 to 10 carbon atoms, with the priviso that at least one of R1 and R2 or R3 and R4 is hydrogen, comprises reacting an iminodiacetonitrile of the formula II STR3 where R1, R2, R3 and R4 have the abovementioned meanings, with formamide of the formula III STR4 in the presence of formic acid or with a compound which provides formic acid, in the presence of acids.
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- Fungal metabolites. II. Structural elucidation of minor metabolites, valinotricin, cyclonerodiol oxide, and epicyclonerodiol oxide, from Trichoderma polysporum
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A new minor metabolite, valinotricin (1), along with cyclonerodiol oxide (9) and epicyclonerodiol oxide (10) was isolated from Trichoderma polysporum. The structure of valinotricin was elucidated as 1 by chemical and spectral studies, and then confirmed by synthesis. Chemical and spectroscopic studies of cyclonerodiol oxide and epicyclonerodiol oxide led to the structures 9 and 10, respectively.
- Fujita,Takaishi,Takeda,et al.
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p. 4419 - 4425
(2007/10/02)
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- SYNTHESIS AND REACTIVITY OF THE BENZIMIDAZOLIDES OF N-FORMYLATED AND N-PROTONATED AMINO ACIDS
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The reactivity of the benzimidazolides of N-formylated and N-protonated amino acids was studied, and it was shown that they can be used in the synthesis of O-aminoacyl derivatives of nucleotides.
- Purygin, P. P.,Pron', A. N.
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p. 908 - 910
(2007/10/02)
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- REAGENTS AND SYNTHETIC METHODS. 30. PRACTICAL AND IMPROVED METHOD FOR FORMYLATING AMINO COMPOUNDS BY MEANS OF FORMIC ACID-DIMETHYLFORMAMIDE SYSTEM.
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Several amino compounds were formylated in high yields by means of formic acid-dimethylformamide, specially D,L-amino acids.The influence of this solvent was also briefly discussed.
- Aizpurua, Jezus Mari,Palomo, Claudio
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p. 745 - 752
(2007/10/02)
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- Substituted amino acids
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Esters and thiolesters of amino acids, intermediates therefor, synthesis thereof, and the use of said esters and thiolesters and compositions for the control of pests.
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- Certain pesticidal substituted amino lower-alkanoates or lower-alkano-thioates containing pyridyl in the ester portion
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Pyridyl esters and thiolesters of amino acids, intermediates therefor, synthesis thereof and the use of said esters and thiolesters and compositions for the control of pests.
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- Isoindolinyl derivatives
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Esters of lower alkanoic acids substituted at the α-position with isoindoline or tetrahydroisoquinoline, and intermediates therefor, useful as pesticides.
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