The Experts below are selected from a list of 363 Experts worldwide ranked by ideXlab platform
Takeo Konakahara - One of the best experts on this subject based on the ideXlab platform.
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hf otf 4 catalyzed regioselective n Aminomethylation of indoles and related nh containing heterocycles
2010Co-Authors: Norio Sakai, Kazuyori Shimamura, Reiko Ikeda, Takeo KonakaharaAbstract:Under Lewis acidic conditions using Hf(OTf)4, the Aminomethylation of an indole derivative with a typical N,O-acetal preferentially produced kinetically favored N-aminomethylated indole derivatives instead of thermodynamically favored 3-aminomethylated indoles.
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a practical approach to non natural or n unsubstituted α arylglycine derivatives hf otf 4 doped me3sicl system catalyzed Aminomethylation of electron rich arenes with a new type of n o acetal
2008Co-Authors: Norio Sakai, Junichi Asano, Yuta Shimano, Takeo KonakaharaAbstract:Abstract The authors have demonstrated the Hf(OTf) 4 -doped Me 3 SiCl system-catalyzed Aminomethylation of electron-rich aromatic compounds, such as indoles and anilines, with new types of N , O -acetals having a variety of functional groups, such as cyano, ester, bis(trimethylsilyl)amino, diallylamino, and cyclic amino moieties, for the preparation of non-natural aromatic amino acid derivatives. Aminomethylation using an N , O -acetal with a bis(trimethylsilyl)amino group was particularly successful in the direct preparation of an N -unsubstituted α-indolylglycine derivative, which required only a standard aqueous workup.
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hf otf 4 doped me3sicl catalyzed Aminomethylation of arenes with n o acetals facile approach to non natural aromatic amino acid precursors
2007Co-Authors: Norio Sakai, Junichi Asano, Yuta Shimano, Takeo KonakaharaAbstract:The authors demonstrated a Hf(OTf) 4 -Me 3 SiCl-system-catalyzed Aminomethylation of an aromatic compound, such as a heterocycle or an electron-rich arene, with several new types of N, O-acetals having both a cyano group and a cyclic amino moiety. This method permits the facile synthesis of artificial aromatic amino acid precursors.
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The Aminomethylation of electron-rich aromatics with an N-silyl-N,O-acetal catalyzed by a metal triflate-TMSCl system: Facile synthesis of aromatic primary amines, 1-aryl-trichloroethylamines
2003Co-Authors: Norio Sakai, Maki Hirasawa, Toshihiro Hamajima, Takeo KonakaharaAbstract:The copper(II) triflate- and hafnium(IV) triflate-catalyzed Aminomethylation of indole (2) with an N-silyl-N,O-acetal 1 containing a trichloromethyl group provides the primary amine derivative (3a)...
Norio Sakai - One of the best experts on this subject based on the ideXlab platform.
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hf otf 4 catalyzed regioselective n Aminomethylation of indoles and related nh containing heterocycles
2010Co-Authors: Norio Sakai, Kazuyori Shimamura, Reiko Ikeda, Takeo KonakaharaAbstract:Under Lewis acidic conditions using Hf(OTf)4, the Aminomethylation of an indole derivative with a typical N,O-acetal preferentially produced kinetically favored N-aminomethylated indole derivatives instead of thermodynamically favored 3-aminomethylated indoles.
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a practical approach to non natural or n unsubstituted α arylglycine derivatives hf otf 4 doped me3sicl system catalyzed Aminomethylation of electron rich arenes with a new type of n o acetal
2008Co-Authors: Norio Sakai, Junichi Asano, Yuta Shimano, Takeo KonakaharaAbstract:Abstract The authors have demonstrated the Hf(OTf) 4 -doped Me 3 SiCl system-catalyzed Aminomethylation of electron-rich aromatic compounds, such as indoles and anilines, with new types of N , O -acetals having a variety of functional groups, such as cyano, ester, bis(trimethylsilyl)amino, diallylamino, and cyclic amino moieties, for the preparation of non-natural aromatic amino acid derivatives. Aminomethylation using an N , O -acetal with a bis(trimethylsilyl)amino group was particularly successful in the direct preparation of an N -unsubstituted α-indolylglycine derivative, which required only a standard aqueous workup.
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hf otf 4 doped me3sicl catalyzed Aminomethylation of arenes with n o acetals facile approach to non natural aromatic amino acid precursors
2007Co-Authors: Norio Sakai, Junichi Asano, Yuta Shimano, Takeo KonakaharaAbstract:The authors demonstrated a Hf(OTf) 4 -Me 3 SiCl-system-catalyzed Aminomethylation of an aromatic compound, such as a heterocycle or an electron-rich arene, with several new types of N, O-acetals having both a cyano group and a cyclic amino moiety. This method permits the facile synthesis of artificial aromatic amino acid precursors.
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The Aminomethylation of electron-rich aromatics with an N-silyl-N,O-acetal catalyzed by a metal triflate-TMSCl system: Facile synthesis of aromatic primary amines, 1-aryl-trichloroethylamines
2003Co-Authors: Norio Sakai, Maki Hirasawa, Toshihiro Hamajima, Takeo KonakaharaAbstract:The copper(II) triflate- and hafnium(IV) triflate-catalyzed Aminomethylation of indole (2) with an N-silyl-N,O-acetal 1 containing a trichloromethyl group provides the primary amine derivative (3a)...
Mykhaylo S. Frasinyuk - One of the best experts on this subject based on the ideXlab platform.
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conjugation of the alkaloid anabasine to coumarins
2019Co-Authors: S P Bondarenko, Volodymyr P. Khilya, V. I. Vinogradova, Galyna P Mrug, Mykhaylo S. FrasinyukAbstract:The possibility of using the alkaloid anabasine in Mannich Aminomethylation of coumarins was studied. Anabasine-coumarin conjugates in which the benzopyrone core was conjugated to anabasine through a methylene linker were synthesized.
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Synthesis of anabasine-containing aminomethyl derivatives of 6-hydroxyaurones
2019Co-Authors: Antonina V. Popova, Svitlana P. Bondarenko, Valentina I. Vinogradova, Mykhaylo S. FrasinyukAbstract:Aminomethylation of aurones was studied by using anabasine. The reaction in the case of 6-hydroxyaurones was shown to selectively provide 7-aminomethyl-6-hydroxyaurones, while 5-aminomethyl-6-hydroxy-7-methylaurones could be obtained by transamination of 5-dimethylaminomethyl derivatives of 6-hydroxy-7-methylaurones in the presence of anabasine.
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synthesis of isoflavone anabasine conjugates
2018Co-Authors: S P Bondarenko, Mykhaylo S. Frasinyuk, V. I. Vinogradova, Galyna P Mrug, Volodymyr P. KhilyaAbstract:Possible Mannich Aminomethylation of isoflavone chromone rings was studied using the alkaloid anabasine. Anabasine-isoflavone conjugates in which the benzopyrone core was connected to anabasine through a methylene linker were synthesized.
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Observations from Aminomethylation of 7-substituted 6-hydroxyaurones
2018Co-Authors: Svitlana P. Bondarenko, Mykhaylo S. FrasinyukAbstract:Aminomethylation of 7-substituted 6-hydroxyaurones was studied using primary and secondary amines. In the case of 6-hydroxy-7-methylaurones, their 5-dialkylaminomethyl derivatives or 7-benzylidene-3,4-dihydro-2 Н -furo[3,2- g ][1,3]benzoxazin-6(7 Н )-ones were formed. The Aminomethylation reaction of 6,7-dihydroxyaurones produced only 5-aminomethyl derivatives.
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synthesis of flavonoid derivatives of cytisine 5 Aminomethylation of 6 hydroxyaurones
2017Co-Authors: Antonina V. Popova, Mykhaylo S. Frasinyuk, S P Bondarenko, E V Podobii, V. I. VinogradovaAbstract:Aminomethylation of 6-hydroxy- and 6-hydroxy-7-methylaurones by the alkaloid cytisine was studied. It was shown that the Aminomethylation of the 6-hydroxyaurones occurred at the 7-position of the benzofuran ring and at the 5-position if the 7-position was occupied.
Hanmin Huang - One of the best experts on this subject based on the ideXlab platform.
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palladium catalyzed Aminomethylation and cyclization of enynol to o heterocycle confined 1 3 dienes
2021Co-Authors: Haocheng Zhang, Hanmin HuangAbstract:The rational tuning of the electrophilicity of the allylpalladium intermediates enables the regioselectively intramolecular 1,2-addition of enynol in the presence of aminal. This Aminomethylation and cyclization reaction via C-N bond activation and intramolecular nucleophilic addition provides a rare example for the synthesis of O-containing heterocycle-confined 1,3-dienes, which is of synthetic potential for further derivatization. The method possesses broad substrate generality as well as functional group compatibility and efficiently affords a wide range of desired products with 5-, 6-, and 8-membered O-containing heterocycles with various functional groups.
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Palladium-Catalyzed Dehydrogenative Difunctionalization of Aminoalkenes with Aminals as Oxidants and Electrophiles
2017Co-Authors: Xibing Zhou, Hanmin HuangAbstract:A novel palladium-catalyzed aminomethylamination of aminoalkenes with an aminal, functioning not only as an Aminomethylation reagent but also as an oxidant, was developed. This direct and operationally simple protocol provides a fundamentally novel and unique approach toward the synthesis of 2-(2-aminoethyl)indoles and 2-(2-aminoethyl)pyrrolidines, which are important building blocks in synthetic organic chemistry. The unity of this method was highlighted by the rapid synthesis of Alosetron, a drug used for the treatment of irritable bowel syndrome
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enantioselective aminomethylamination of conjugated dienes with aminals enabled by chiral palladium complex catalyzed c n bond activation
2016Co-Authors: Yang Liu, Yinjun Xie, Hongli Wang, Hanmin HuangAbstract:A novel highly enantioselective aminomethylamination of conjugated dienes with aminals catalyzed by a chiral palladium complex ligated with BINOL-derived chiral diphosphinite has been successfully developed. This reaction proceeds via a Pd-catalyzed cascade C–N bond activation, Aminomethylation, and asymmetric allylic amination reaction under mild reaction conditions, providing a unique and efficient strategy for the synthesis of enantiomerically pure allylic 1,3-diamines.
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Enantioselective Aminomethylamination of Conjugated Dienes with Aminals Enabled by Chiral Palladium Complex-Catalyzed C–N Bond Activation
2016Co-Authors: Yang Liu, Yinjun Xie, Hongli Wang, Hanmin HuangAbstract:A novel highly enantioselective aminomethylamination of conjugated dienes with aminals catalyzed by a chiral palladium complex ligated with BINOL-derived chiral diphosphinite has been successfully developed. This reaction proceeds via a Pd-catalyzed cascade C–N bond activation, Aminomethylation, and asymmetric allylic amination reaction under mild reaction conditions, providing a unique and efficient strategy for the synthesis of enantiomerically pure allylic 1,3-diamines
Dan Zhang - One of the best experts on this subject based on the ideXlab platform.
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privilege structure oriented three component asymmetric Aminomethylation assembly of chiral 3 aminomethyl indolones
2019Co-Authors: Zhenghui Kang, Dan ZhangAbstract:The asymmetric Aminomethylation reaction of 3-diazooxindoles with electronic-rich arenes and N,O-acetals cooperatively catalyzed by achiral dirhodium complex and chiral phosphoric acid is reported. The reaction provides a novel method for the facile synthesis of chiral 3-aminomethyl oxindoles with an all-carbon quaternary center in good yields (82-98%) with high to excellent enantioselectivities (up to 97% ee). The transformation proceeds through a convergent addition of a reactive zwitterionic intermediate with a chiral methylene iminium generated in situ via asymmetric counteranion-directed catalysis (ACDC). This work represents the first asymmetric Aminomethylation method of mixed 3,3'-bisindoles with structural diversity.
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asymmetric counter anion directed Aminomethylation synthesis of chiral β amino acids via trapping of an enol intermediate
2019Co-Authors: Zhenghui Kang, Yongheng Wang, Dan ZhangAbstract:A novel enantioselective Aminomethylation reaction of diazo compound, alcohol and α-aminomethyl ether enabled by asymmetric counteranion-directed catalysis is disclosed that offers an efficient and convenient access to furnish optically active α-hydroxyl-β-amino acids in high yield with high to excellent enantioselectivities. Control experiments and DFT calculations indicate that the transformation proceeds through trapping the in situ generated enol intermediate with methylene iminium ion, and the asymmetric induction was enabled by chiral pentacarboxycyclopentadiene anion via H-bonding and electrostatic interaction.
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Asymmetric Counter-Anion-Directed Aminomethylation: Synthesis of Chiral β‑Amino Acids via Trapping of an Enol Intermediate
2019Co-Authors: Zhenghui Kang, Yongheng Wang, Dan ZhangAbstract:A novel enantioselective Aminomethylation reaction of diazo compound, alcohol and α-aminomethyl ether enabled by asymmetric counteranion-directed catalysis is disclosed that offers an efficient and convenient access to furnish optically active α-hydroxyl-β-amino acids in high yield with high to excellent enantioselectivities. Control experiments and DFT calculations indicate that the transformation proceeds through trapping the in situ generated enol intermediate with methylene iminium ion, and the asymmetric induction was enabled by chiral pentacarboxycyclopentadiene anion via H-bonding and electrostatic interaction