- One-pot, large-scale synthesis of nickel(II) complexes derived from 2-[N-(α-Picolyl)amino]benzophenone (PABP) and α- or β-amino acids
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(Chemical Equation Presented) A one-pot, large-scale procedure for preparing the Belokon-Soloshonok nucleophilic glycine equivalent 2-[N-(α-picolyl)amino]benzophenone (PABP) derived Ni(II) complex [GlyNi(II)PABP] is described. It has been accomplished by
- Deng, Guanghui,Wang, Jiang,Zhou, Yu,Jiang, Hualiang,Liu, Hong
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- Efficient synthesis of serically constrained smmetrically alpha,alpha-disubstituted alpha-amino acids under operationally convenient conditions.
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Homologation of the nucleophilic glycine equivalent Ni-Gly-PABP [Ni(II) complex of glycine Schiff base with 2-[N-(alpha-picolyl)amino]benzophenone (PABP)] 2 via alkyl halide alkylations and Michael addition reactions was systematically studied as a general method for preparing symmetrically alpha,alpha-disubstituted alpha-amino acids (sym-alpha,alpha-AA). The dialkylation reactions are conducted under operationally convenient conditions without recourse to inert atmosphere, dried solvents, and low temperatures, thus enjoying key advantages of the experimental simplicity and attractive cost structure. The method has been shown to be particularly successful for the dialkylation of complex 2 with activated and nonactivated alkyl halides, including propargyl derivatives, affording a generalized and practical access to the corresponding sym-alpha,alpha-AA. This study has also shown some limitation of the method, as it cannot be extended to alpha- or beta-branched alkyl halides or Michael acceptors to be used for the dialkylation of glycine equivalent 2. High chemical yields of the dialkylated products, combined with the simplicity of the experimental procedure, render this method worth immediate use for multigram scale preparation of the sym-alpha,alpha-AA.
- Ellis, Trevor K,Martin, Collin H,Tsai, Gary M,Ueki, Hisanori,Soloshonok, Vadim A
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- Efficient large-scale synthesis of picolinic acid-derived nickel(II) complexes of glycine
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An efficient, large-scale method for the preparation of 2-[N-(α-picolyl)amino]acetophenone (PAAP) and 2-[N-(α-picolyl)-amino] benzophenone (PABP), the hitherto unknown 4-methyl-2-[N-(α-picolyl)amino] benzophenone (4-Me-PABP) and 4-nitro-2-[N-(α-picolyl)am
- Ueki, Hisanori,Ellis, Trevor K.,Martin, Collin H.,Soloshonok, Vadim A.
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- Preparation of labeled aromatic amino acids: Via late-stage18F-fluorination of chiral nickel and copper complexes
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A general protocol for the preparation of 18F-labeled AAAs and α-methyl-AAAs applying alcohol-enhanced Cu-mediated radiofluorination of Bpin-substituted chiral complexes using Ni/Cu-BPX templates as double protecting groups is reported. The chiral auxiliaries are easily accessible from commercially available starting materials in a few synthetic steps. The versatility of the method was demonstrated by the high-yielding preparation of a series of [18F]F-AAAs and the successful implementation of the protocol into automated radiosynthesis modules. This journal is
- Craig, Austin,Kolks, Niklas,Urusova, Elizaveta A.,Zischler, Johannes,Brugger, Melanie,Endepols, Heike,Neumaier, Bernd,Zlatopolskiy, Boris D.
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supporting information
p. 9505 - 9508
(2020/09/03)
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- Convenient synthesis of racemic 4,4-difluoro glutamic acid derivatives via Michael-type additions of Ni(II)-complex of dehydroalanine Schiff bases
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Michael-type addition reactions of Ni(II)-complex of a dehydroalanine Schiff base and ethyl bromodifluoroacetate in the presence of copper for the synthesis of racemic 4,4,-difluoroglutamic acid derivatives were developed. These reactions proceeded smooth
- Tokairin, Yoshinori,Soloshonok, Vadim A.,Konno, Hiroyuki,Moriwaki, Hiroki,R?schenthaler, Gerd-Volker
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- Synthesis of polysubstituted β-amino cyclohexane carboxylic acids via Diels-Alder reaction using Ni(II)-complex stabilized β-alanine derived dienes
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This paper describes the design and synthesis of a new class of β-alanine derived dienes stabilized by Ni(II)-complex. Preliminary study of their Diels-Alder cycloaddition reactions with several types of dienophiles demonstrates their significant synthetic potential for the preparation of various polyfunctional β-aminocyclohexane carboxylic acids.
- Ding, Xiao,Wang, Hengshuai,Wang, Jiang,Wang, Sinan,Lin, Daizong,Lv, Li,Zhou, Yu,Luo, Xiaomin,Jiang, Hualiang,Acena, Jose Luis,Soloshonok, Vadim A.,Liu, Hong
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p. 791 - 796
(2013/07/25)
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- Pd-catalyzed arylation/oxidation of benzylic C-H bond
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A palladium-catalyzed benzylic C-H arylation/oxidation reaction leading to diaryl ketones has been accomplished. The indispensable role of the bidentate system is disclosed for this sequential process. This chemistry offers a direct new access to a range of diarylketones.
- Xie, Yongju,Yang, Yuzhu,Huang, Lehao,Zhang, Xunbin,Zhang, Yuhong
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p. 1238 - 1241
(2012/05/20)
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- Synthesis, crystal structure, and in vitro antitumor activities of copper(II) complexes containing tetradentate pyridine-based ligands
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Several new Cu(II) complexes of Schiff bases obtained by condensation of 2-[N-(α-picolyl)-amino]-benzophenone with different chiral amino acids were synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structure of one
- Yang, Xin-Tao,Wu, Hao,Ma, Shi-Jun,Hu, Juan-Juan,Wang, Yong-Mei
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experimental part
p. 403 - 407
(2012/03/08)
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- Virtually complete control of simple and face diastereoselectivity in the Michael addition reactions between achiral equivalents of a nucleophilic glycine and (S)- or (R)-3-(E-enoyl)-4-phenyl-1,3-oxazolidin-2-ones: Practical method for preparation of β-substituted pyroglutamic acids and prolines
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This study demonstrates a new strategy for controlling the stereochemical outcome of the Michael addition reactions between nucleophilic glycine equivalents and α,β-unsaturated carboxylic acid derivatives: The addition reactions between achiral Ni(II)-complex of the Schiff base of glycine with o-[N-α-pycolylamino]acetophenone and (S)- or (R)-3-(E-enoyl)-4- phenyl-1,3-oxazolidin-2-ones were shown to occur at room temperature in the presence of nonchelating organic bases and, most notably, with very high stereoselectivity at both newly formed stereogenic centers. Thus, the chiral 4-phenyl-1,3-oxazolidin-2-one moiety was found to control efficiently both face diastereoselectivities of the glycine derived enolate and the C,C double bond of the Michael acceptor. The new strategy developed in this work is methodologically superior to previous methods, most notably in terms of generality and synthetic efficiency. Excellent chemical yields and diastereoselectivities, combined with the simplicity of the experimental procedures, render the present method of immediate use for preparing various 3-substituted pyroglutamic acids and related amino acids (glutamic acids, glutamines, prolines, etc.) available via conventional transformations of the former.
- Soloshonok, Vadim A.,Ueki, Hisanori,Tiwari, Rohit,Cai, Chaozhong,Hruby, Victor J.
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p. 4984 - 4990
(2007/10/03)
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- Synthesis of α-Amino Acids via Asymmetric Phase Transfer-Catalyzed Alkylation of Achiral Nickel(II) Complexes of Glycine-Derived Schiff Bases
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Achiral, diamagnetic Ni(II) complexes 1 and 3 have been synthesized from Ni(II) salts and the Schiff bases, generated from glycine and PBP (7) and PBA (11), respectively, in MeONa/MeOH solutions. The requisite carbonyl-derivatizing agents pyridine-2-carboxylic acid(2-benzoyl-phenyl)-amide 7 (PBP) and pyridine-2-carboxylic acid(2-formyl-phenyl)-amide 11 (PBA) were readily prepared from picolinic acid and o-aminobenzophenone or picolinic acid and methyl o-anthranilate, respectively. The structure of 1 was established by X-ray crystallography. Complexes 1 and 3 were found to undergo C-alkylation with alkyl halides under PTC conditions in the presence of β-naphthol or benzyltriethylammonium bromide as catalysts to give mono- and bis-alkylated products, respectively. Decomposition of the complexes with aqueous HCI under mild conditions gave the required amino acids, and PBP and PBA were recovered. Alkylation of 1 with highly reactive alkyl halides, carried out under the PTC conditions in the presence of 10% mol of (S)- or (R)-2-hydroxy-2′ -amino-1,1′-binaphthyl 31a (NOBIN) and/or its N-acyl derivatives and by (S)- or (R)-2-hydroxy-8′-amino-1,1′-binaphthyl 32a (iso-NOBIN) and its N-acyl derivatives, respectively, gave rise to α-amino acids with high enantioselectivities (90-98.5% ee) in good-to-excellent chemical yields at room temperature within several minutes. An unusually large positive nonlinear effect was observed in these reactions. The Michael addition of acrylic derivatives 37 to 1 was conducted under similar conditions with up to 96% ee. The 1H NMR and IR spectra of a mixture of the sodium salt of NOBIN and 1 indicated formation of a complex between the two components. Implications of the association and self-association of NOBIN for the observed sense of asymmetric induction and nonlinear effects are discussed.
- Belokon, Yuri N.,Bespalova, Natalia B.,Churkina, Tatiana D.,Cisarova, Ivana,Ezernitskaya, Marina G.,Harutyunyan, Syuzanna R.,Hrdina, Radim,Kagan, Henri B.,Kocovsky, Pavel,Kochetkov, Konstantin A.,Larionov, Oleg V.,Lyssenko, Konstantin A.,North, Michael,Polasek, Miroslav,Peregudov, Alexander S.,Prisyazhnyuk, Vladimir V.,Vyskocil, Stepan
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p. 12860 - 12871
(2007/10/03)
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- Highly efficient catalytic synthesis of α-amino acids under phase-transfer conditions with a novel catalyst/substrate pair
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A facile and fast enantioselective synthesis of α-amino acids with high ee values was achieved by the asymmetric alkylation of the glycine derivative 1 under phase-transfer conditions with (R)-2-amino-2′-hydrozy-1,1′-binaphthyl (NOBIN; see sceme). The ee value of the amino acid products. This occures as a results of a significant positive nonlinear effect in the alkylation reaction.
- Belokon, Yuri N.,Kochetkov, Konstantin A.,Churkina, Tatiana D.,Ikonnikov, Nikolai S.,Larionov, Oleg V.,Harutyunyan, Syuzanna R.,Vyskocil, Stepan,North, Michael,Kagan, Henri B.
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p. 1948 - 1951
(2007/10/03)
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