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Kenso Soai - One of the best experts on this subject based on the ideXlab platform.
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formation of enantioenriched alkanol with stochastic distribution of enantiomers in the absolute asymmetric synthesis under heterogeneous solid vapor phase conditions
Chemical Communications, 2019Co-Authors: Yoshiyasu Kaimori, Arimasa Matsumoto, Tsuneomi Kawasaki, Yui Hiyoshi, Kenso SoaiAbstract:Among several theories proposed for the origin of homochirality, absolute asymmetric synthesis is unique because it produces chiral compounds without the intervention of any chiral factor. Here we report on the kinetically controlled heterogeneous solid–vapor phase absolute asymmetric synthesis in conjunction with asymmetric Autocatalysis with amplification of chirality. Each reaction, carried out in a test tube, between achiral powder crystals of pyrimidine-5-carbaldehyde and the vapor of diisopropylzinc, is controlled kinetically to afford either (S)- or (R)-pyrimidyl alkanol.
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Role of Asymmetric Autocatalysis in the Elucidation of Origins of Homochirality of Organic Compounds
'MDPI AG', 2019Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:Pyrimidyl alkanol and related compounds were found to be asymmetric autocatalysts in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde and related aldehydes. In the asymmetric Autocatalysis with amplification of enantiomeric excess (ee), the very low ee (ca. 0.00005%) of 2-alkynyl-5-pyrimidyl alkanol was significantly amplified to >99.5% ee with an increase in the amount. By using asymmetric Autocatalysis with amplification of ee, several origins of homochirality have been examined. Circularly polarized light, chiral quartz, and chiral crystals formed from achiral organic compounds such as glycine and carbon (13C/12C), nitrogen (15N/14N), oxygen (18O/16O), and hydrogen (D/H) chiral isotopomers were found to act as the origin of chirality in asymmetric Autocatalysis. And the spontaneous absolute asymmetric synthesis was also realized without the intervention of any chiral factor
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asymmetric Autocatalysis of pyrimidyl alkanol and related compounds self replication amplification of chirality and implication for the origin of biological enantioenriched chirality
Tetrahedron, 2018Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:Abstract We discovered asymmetric Autocatalysis in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde, where the product 5-pyrimidyl alkanol acts as a highly efficient asymmetric autocatalyst to afford more of itself (Soai reaction). Asymmetric Autocatalysis proceeded quantitatively (>99% yield), affording itself as a near enantiomerically pure (>99.5% ee) product. An extremely low enantiomeric excess (ca. 0.00005% ee) can automultiply during three rounds of consecutive asymmetric Autocatalysis to >99.5% ee by asymmetric amplification. Circularly polarized light, and inorganic and organic crystals, act as the origin of chirality to trigger asymmetric Autocatalysis. Asymmetric Autocatalysis has enormous power to recognize and amplify the chirality of hydrogen, carbon, oxygen, and nitrogen isotopomers. Moreover, absolute asymmetric synthesis, i.e., the formation of enantioenriched compounds without the intervention of any chiral factor, is realized by asymmetric Autocatalysis. By using designed molecules based on 5-pyrimidyl alkanol, the intramolecular asymmetric control, self-replication, and improvement of chiral multifunctionalized large molecules has been developed by applying asymmetric Autocatalysis.
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unusual reversal of enantioselectivity in the asymmetric Autocatalysis of pyrimidyl alkanol triggered by chiral aromatic alkanols and amines
Organic and Biomolecular Chemistry, 2017Co-Authors: Arimasa Matusmoto, Satoshi Fujiwara, Yui Hiyoshi, Kerstin Zawatzky, Alexey A Makarov, Christopher J Welch, Kenso SoaiAbstract:Temperature dependent inversion of enantioselectivity in asymmetric catalysis is an interesting and somewhat unusual phenomenon. We have observed temperature dependent inversion of enantioselectivity in the asymmetric Autocatalysis reaction when triggered by a wide scope of enantioenriched alcohols and amines. The addition reaction of diisopropylzinc to pyrimidine-5-carbaldehyde in the presence of enantiopure alcohols or amines affords the pyrimidyl alkanol product at 0 °C with high ee. However, lowering the reaction temperature to −44 °C affords the opposite enantioselectivity.
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crystal structure of the isopropylzinc alkoxide of pyrimidyl alkanol mechanistic insights for asymmetric Autocatalysis with amplification of enantiomeric excess
Angewandte Chemie, 2015Co-Authors: Arimasa Matsumoto, Tsuneomi Kawasaki, Takaaki Abe, Atsushi Hara, Takayuki Tobita, Taisuke Sasagawa, Kenso SoaiAbstract:Asymmetric amplification during self-replication is a key feature that is used to explain the origin of homochirality. Asymmetric Autocatalysis of pyrimidyl alkanol in the asymmetric addition of diisopropylzinc to pyrimidine-5-carbaldehyde is a unique example of this phenomenon. Crystallization of zinc alkoxides of this 5-pyrimidyl alkanol and single-crystal X-ray diffraction analysis of the alkoxide crystals reveal the existence of tetramer or higher oligomer structures in this asymmetric autocatalytic system.
Itaru Sato - One of the best experts on this subject based on the ideXlab platform.
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enantioselective synthesis of near enantiopure compound by asymmetric Autocatalysis triggered by asymmetric photolysis with circularly polarized light
Journal of the American Chemical Society, 2005Co-Authors: Tsuneomi Kawasaki, Itaru Sato, Mirai Sato, Saori Ishiguro, Takahiro Saito, Yosuke Morishita, Hideo Nishino, Yoshihisa Inoue, Kenso SoaiAbstract:Right- and left-handed circularly polarized light (CPL) has been proposed as one of the origins of homochirality of biomolecules. However, the enantiomeric excess induced by CPL has been only very low ( 99.5% ee. On the other hand, irradiation with l-CPL affords (S)-pyrimidyl alkanol with >99.5% ee. Thus, chiral physical power, such as CPL, in conjunction with asymmetric Autocatalysis, provides a highly enantioenriched compound.
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highly enantioselective asymmetric Autocatalysis induced by chiral ionic crystals of sodium chlorate and sodium bromate
Journal of Molecular Catalysis A-chemical, 2004Co-Authors: Itaru Sato, Kousuke Kadowaki, Yasushi Ohgo, Kenso SoaiAbstract:Chiral crystals of sodium chlorate and sodium bromate induced highly enantioselective organic synthesis in combination with asymmetric Autocatalysis. (S)-5-Pyrimidyl alkanols with up to 98% ee were obtained in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehydes in the presence of d-sodium chlorate. On the other hand, (R)-5-pyrimidyl alkanols with up to 98% ee were obtained for the corresponding reaction in the presence of l-sodium chlorate. Chiral crystals of d- and l-sodium bromate were also found to work as chiral initiators.
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relationship between the time yield and enantiomeric excess of asymmetric Autocatalysis of chiral 2 alkynyl 5 pyrimidyl alkanol with amplification of enantiomeric excess
Tetrahedron-asymmetry, 2003Co-Authors: Itaru Sato, Daisuke Omiya, Hiroyoshi Igarashi, Keiichi Kato, Yoshihiro Ogi, Koichi Tsukiyama, Kenso SoaiAbstract:Experimental and kinetic analysis of asymmetric Autocatalysis with amplification of ee in the enantioselective addition of diisopropylzinc to 2-alkynylpyrimidine-5-carbaldehyde using chiral 2-alkynyl-5-pyrimidyl alkanol with low ee's are described.
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asymmetric synthesis of pyrimidyl alkanol without adding chiral substances by the addition of diisopropylzinc to pyrimidine 5 carbaldehyde in conjunction with asymmetric Autocatalysis
Tetrahedron-asymmetry, 2003Co-Authors: Kenso Soai, Itaru Sato, Takanori Shibata, Soichiro Komiya, Masanobu Hayashi, Yohei Matsueda, Hikaru Imamura, Tadakatsu Hayase, Hiroshi Morioka, Hayami TabiraAbstract:Enantiomerically enriched pyrimidyl alkanol with either S or R configuration was obtained stochastically from the reaction between pyrimidine-5-carbaldehyde and diisopropylzinc without adding chiral substances in conjunction with subsequent asymmetric Autocatalysis, leading to amplification of the enantiomeric excess.
Tsuneomi Kawasaki - One of the best experts on this subject based on the ideXlab platform.
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formation of enantioenriched alkanol with stochastic distribution of enantiomers in the absolute asymmetric synthesis under heterogeneous solid vapor phase conditions
Chemical Communications, 2019Co-Authors: Yoshiyasu Kaimori, Arimasa Matsumoto, Tsuneomi Kawasaki, Yui Hiyoshi, Kenso SoaiAbstract:Among several theories proposed for the origin of homochirality, absolute asymmetric synthesis is unique because it produces chiral compounds without the intervention of any chiral factor. Here we report on the kinetically controlled heterogeneous solid–vapor phase absolute asymmetric synthesis in conjunction with asymmetric Autocatalysis with amplification of chirality. Each reaction, carried out in a test tube, between achiral powder crystals of pyrimidine-5-carbaldehyde and the vapor of diisopropylzinc, is controlled kinetically to afford either (S)- or (R)-pyrimidyl alkanol.
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Role of Asymmetric Autocatalysis in the Elucidation of Origins of Homochirality of Organic Compounds
'MDPI AG', 2019Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:Pyrimidyl alkanol and related compounds were found to be asymmetric autocatalysts in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde and related aldehydes. In the asymmetric Autocatalysis with amplification of enantiomeric excess (ee), the very low ee (ca. 0.00005%) of 2-alkynyl-5-pyrimidyl alkanol was significantly amplified to >99.5% ee with an increase in the amount. By using asymmetric Autocatalysis with amplification of ee, several origins of homochirality have been examined. Circularly polarized light, chiral quartz, and chiral crystals formed from achiral organic compounds such as glycine and carbon (13C/12C), nitrogen (15N/14N), oxygen (18O/16O), and hydrogen (D/H) chiral isotopomers were found to act as the origin of chirality in asymmetric Autocatalysis. And the spontaneous absolute asymmetric synthesis was also realized without the intervention of any chiral factor
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asymmetric Autocatalysis of pyrimidyl alkanol and related compounds self replication amplification of chirality and implication for the origin of biological enantioenriched chirality
Tetrahedron, 2018Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:Abstract We discovered asymmetric Autocatalysis in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde, where the product 5-pyrimidyl alkanol acts as a highly efficient asymmetric autocatalyst to afford more of itself (Soai reaction). Asymmetric Autocatalysis proceeded quantitatively (>99% yield), affording itself as a near enantiomerically pure (>99.5% ee) product. An extremely low enantiomeric excess (ca. 0.00005% ee) can automultiply during three rounds of consecutive asymmetric Autocatalysis to >99.5% ee by asymmetric amplification. Circularly polarized light, and inorganic and organic crystals, act as the origin of chirality to trigger asymmetric Autocatalysis. Asymmetric Autocatalysis has enormous power to recognize and amplify the chirality of hydrogen, carbon, oxygen, and nitrogen isotopomers. Moreover, absolute asymmetric synthesis, i.e., the formation of enantioenriched compounds without the intervention of any chiral factor, is realized by asymmetric Autocatalysis. By using designed molecules based on 5-pyrimidyl alkanol, the intramolecular asymmetric control, self-replication, and improvement of chiral multifunctionalized large molecules has been developed by applying asymmetric Autocatalysis.
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crystal structure of the isopropylzinc alkoxide of pyrimidyl alkanol mechanistic insights for asymmetric Autocatalysis with amplification of enantiomeric excess
Angewandte Chemie, 2015Co-Authors: Arimasa Matsumoto, Tsuneomi Kawasaki, Takaaki Abe, Atsushi Hara, Takayuki Tobita, Taisuke Sasagawa, Kenso SoaiAbstract:Asymmetric amplification during self-replication is a key feature that is used to explain the origin of homochirality. Asymmetric Autocatalysis of pyrimidyl alkanol in the asymmetric addition of diisopropylzinc to pyrimidine-5-carbaldehyde is a unique example of this phenomenon. Crystallization of zinc alkoxides of this 5-pyrimidyl alkanol and single-crystal X-ray diffraction analysis of the alkoxide crystals reveal the existence of tetramer or higher oligomer structures in this asymmetric autocatalytic system.
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asymmetric Autocatalysis of pyrimidyl alkanol and its application to the study on the origin of homochirality
ChemInform, 2015Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:ConspectusAmplification of enantiomeric excess (ee) is a key feature for the chemical evolution of biological homochirality from the origin of chirality. We describe the amplification of ee in the asymmetric Autocatalysis of 5-pyrimidyl alkanols in the reaction between diisopropylzinc (i-Pr2Zn) and pyrimidine-5-carbaldehydes. During the reaction, an extremely low ee (ca. 0.00005% ee) can be amplified to >99.5% ee, and therefore, the initial slightly major enantiomer is automultiplied by a factor of ca. 630000, while the initial slightly minor enantiomer is automultiplied by a factor of less than 1000. In addition, pyrimidyl alkanols with various substituents at the 2-position of the pyrimidine ring, 3-quinolyl alkanol, 5-carbamoyl-3-pyridyl alkanol, and large multifunctionalized pyrimidyl alkanols also act as highly efficient asymmetric autocatalysts in the addition of i-Pr2Zn to the corresponding aldehydes.The asymmetric Autocatalysis of pyrimidyl alkanol can discriminate the chirality of various compoun...
Arimasa Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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formation of enantioenriched alkanol with stochastic distribution of enantiomers in the absolute asymmetric synthesis under heterogeneous solid vapor phase conditions
Chemical Communications, 2019Co-Authors: Yoshiyasu Kaimori, Arimasa Matsumoto, Tsuneomi Kawasaki, Yui Hiyoshi, Kenso SoaiAbstract:Among several theories proposed for the origin of homochirality, absolute asymmetric synthesis is unique because it produces chiral compounds without the intervention of any chiral factor. Here we report on the kinetically controlled heterogeneous solid–vapor phase absolute asymmetric synthesis in conjunction with asymmetric Autocatalysis with amplification of chirality. Each reaction, carried out in a test tube, between achiral powder crystals of pyrimidine-5-carbaldehyde and the vapor of diisopropylzinc, is controlled kinetically to afford either (S)- or (R)-pyrimidyl alkanol.
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Role of Asymmetric Autocatalysis in the Elucidation of Origins of Homochirality of Organic Compounds
'MDPI AG', 2019Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:Pyrimidyl alkanol and related compounds were found to be asymmetric autocatalysts in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde and related aldehydes. In the asymmetric Autocatalysis with amplification of enantiomeric excess (ee), the very low ee (ca. 0.00005%) of 2-alkynyl-5-pyrimidyl alkanol was significantly amplified to >99.5% ee with an increase in the amount. By using asymmetric Autocatalysis with amplification of ee, several origins of homochirality have been examined. Circularly polarized light, chiral quartz, and chiral crystals formed from achiral organic compounds such as glycine and carbon (13C/12C), nitrogen (15N/14N), oxygen (18O/16O), and hydrogen (D/H) chiral isotopomers were found to act as the origin of chirality in asymmetric Autocatalysis. And the spontaneous absolute asymmetric synthesis was also realized without the intervention of any chiral factor
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asymmetric Autocatalysis of pyrimidyl alkanol and related compounds self replication amplification of chirality and implication for the origin of biological enantioenriched chirality
Tetrahedron, 2018Co-Authors: Kenso Soai, Tsuneomi Kawasaki, Arimasa MatsumotoAbstract:Abstract We discovered asymmetric Autocatalysis in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde, where the product 5-pyrimidyl alkanol acts as a highly efficient asymmetric autocatalyst to afford more of itself (Soai reaction). Asymmetric Autocatalysis proceeded quantitatively (>99% yield), affording itself as a near enantiomerically pure (>99.5% ee) product. An extremely low enantiomeric excess (ca. 0.00005% ee) can automultiply during three rounds of consecutive asymmetric Autocatalysis to >99.5% ee by asymmetric amplification. Circularly polarized light, and inorganic and organic crystals, act as the origin of chirality to trigger asymmetric Autocatalysis. Asymmetric Autocatalysis has enormous power to recognize and amplify the chirality of hydrogen, carbon, oxygen, and nitrogen isotopomers. Moreover, absolute asymmetric synthesis, i.e., the formation of enantioenriched compounds without the intervention of any chiral factor, is realized by asymmetric Autocatalysis. By using designed molecules based on 5-pyrimidyl alkanol, the intramolecular asymmetric control, self-replication, and improvement of chiral multifunctionalized large molecules has been developed by applying asymmetric Autocatalysis.
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crystal structure of the isopropylzinc alkoxide of pyrimidyl alkanol mechanistic insights for asymmetric Autocatalysis with amplification of enantiomeric excess
Angewandte Chemie, 2015Co-Authors: Arimasa Matsumoto, Tsuneomi Kawasaki, Takaaki Abe, Atsushi Hara, Takayuki Tobita, Taisuke Sasagawa, Kenso SoaiAbstract:Asymmetric amplification during self-replication is a key feature that is used to explain the origin of homochirality. Asymmetric Autocatalysis of pyrimidyl alkanol in the asymmetric addition of diisopropylzinc to pyrimidine-5-carbaldehyde is a unique example of this phenomenon. Crystallization of zinc alkoxides of this 5-pyrimidyl alkanol and single-crystal X-ray diffraction analysis of the alkoxide crystals reveal the existence of tetramer or higher oligomer structures in this asymmetric autocatalytic system.
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Asymmetric Autocatalysis Triggered by Chiral Crystal of Achiral Ethylenediamine Sulfate.
ChemInform, 2015Co-Authors: Arimasa Matsumoto, Takahiro Ide, Yoshiyasu Kaimori, Satoshi Fujiwara, Kenso SoaiAbstract:Achiral ethylenediamine forms chiral structures spontaneously when crystallized as the sulfate salt.
Yoshiyasu Kaimori - One of the best experts on this subject based on the ideXlab platform.
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formation of enantioenriched alkanol with stochastic distribution of enantiomers in the absolute asymmetric synthesis under heterogeneous solid vapor phase conditions
Chemical Communications, 2019Co-Authors: Yoshiyasu Kaimori, Arimasa Matsumoto, Tsuneomi Kawasaki, Yui Hiyoshi, Kenso SoaiAbstract:Among several theories proposed for the origin of homochirality, absolute asymmetric synthesis is unique because it produces chiral compounds without the intervention of any chiral factor. Here we report on the kinetically controlled heterogeneous solid–vapor phase absolute asymmetric synthesis in conjunction with asymmetric Autocatalysis with amplification of chirality. Each reaction, carried out in a test tube, between achiral powder crystals of pyrimidine-5-carbaldehyde and the vapor of diisopropylzinc, is controlled kinetically to afford either (S)- or (R)-pyrimidyl alkanol.
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Asymmetric Autocatalysis Triggered by Chiral Crystal of Achiral Ethylenediamine Sulfate.
ChemInform, 2015Co-Authors: Arimasa Matsumoto, Takahiro Ide, Yoshiyasu Kaimori, Satoshi Fujiwara, Kenso SoaiAbstract:Achiral ethylenediamine forms chiral structures spontaneously when crystallized as the sulfate salt.
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Asymmetric Autocatalysis Triggered by Chiral Crystal of Achiral Ethylenediamine Sulfate
Chemistry Letters, 2015Co-Authors: Arimasa Matsumoto, Takahiro Ide, Yoshiyasu Kaimori, Satoshi Fujiwara, Kenso SoaiAbstract:Achiral ethylenediamine forms chiral structures spontaneously when crystallized as the sulfate salt. By using these chiral crystals of ethylenediamine sulfate (ethylenediammonium sulfate), asymmetr...
