Prediction of Soai Reaction Enantioselectivity Induced by Crystals of<i>N</i>-(2-Thienylcarbonyl)glycine

Carter, Damien J.; Rohl, Andrew L.; Shtukenberg, Alexander G.; Bian, Shudan; Hu, Chunhua; Baylon, Lisa; Kahr, Bart; Mineki, Hiroko; Abe, K.; Kawasaki, Tsuneomi; Soai, Kenso

doi:10.1021/cg300207d

Cited by 32 publications

(24 citation statements)

References 82 publications

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“…16 Height and deflection images of the crystal surface micromorphology were obtained with an atomic force microscope (AFM) (MFP-3D-SA System, Asylum Research) working in contact mode at a deflection of 2.0 V. In order to prepare samples for transmission electron microscopy (TEM) the TVM-Cu grids were glued on glass substrates (3-10 mm from its bottom end) and crystals grew directly on the grids. TEM images of HA crystals were recorded using a Zeiss Libra 120 microscope (Carl Zeiss SMT AG Company, Oberkochen, Germany) operated at 120 kV and equipped with a LaB 6 emitter with a Koehler illumination 14 The values of n are exponents in the fit P = kh n .…”

Section: Characterizationmentioning

confidence: 99%

Mechanics of twisted hippuric acid crystals untwisting as they grow

et al. 2015

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Spontaneous twisting of single crystals is a common growth induced deformation. But as twisted crystals thicken they can untwist. restoring a straight form. The mechanics of this process was studied for vapor grown needle-like crystals of N-benzoylglycine (hippuric acid) and N-(2-thienylcarbonyl)glycine, and analyzed by phenomenological models. The elastic stress at the crystal tip undergoes plastic relaxation leading to the twisting deformations. As the crystal grows and thickens it partially untwists showing linear increases of the twist period with crystal thickness. Such behavior was simulated with a model that assumes the constant density of defects in successive growth layers. However. transmission electron microscopy does not reveal any dislocations or other extended defects typically associated with plastic deformation. Published data on other materials show the linear dependencies of pitch on thickness suggesting comparable untwisting mechanisms for different materials.

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Section: Characterizationmentioning

confidence: 99%

Mechanics of twisted hippuric acid crystals untwisting as they grow

et al. 2015

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“…Further study should be directed to understand how chiral source induced the initial imbalance of ee including the absolute handedness before starting the amplification cycle in asymmetric autocatalysis. 57 …”

Section: Discovery Of Asymmetric Autocatalysis With Amplification Of mentioning

confidence: 99%

Asymmetric Autocatalysis of Pyrimidyl Alkanol and Its Application to the Study on the Origin of Homochirality

Soai¹,

Kawasaki

Matsumoto³

2014

Acc. Chem. Res.

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157

103

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CONSPECTUS: Amplification 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 compounds. Chiral substances such as alcohols, amino acids, hydrocarbons, metal complexes, and heterogeneous chiral materials can act as chiral triggers for asymmetric autocatalysis to afford pyrimidyl alkanols with the corresponding absolute configuration of the initiator. This recognition ability of chiral compounds is extremely high, and chiral discrimination of a cryptochiral quaternary saturated hydrocarbon was established by applying asymmetric autocatalysis. By using the large amplification effect of the asymmetric autocatalysis, we can link various proposed origins of chirality with highly enantioenriched organic compounds in conjunction with asymmetric autocatalysis. Thus, a statistical fluctuation in ee of racemic compounds can be amplified to high ee by using asymmetric autocatalysis. Enantiomeric imbalance induced by irradiation of circularly polarized light can affect the enantioselectivity of asymmetric autocatalysis. The asymmetric autocatalysis was also triggered by the morphology of inorganic chiral crystals such as quartz, sodium chlorate, and cinnabar. Chiral organic crystals of achiral compounds also act as chiral initiators, and during the study of a crystal of cytosine, enantioselective chiral crystal phase transformation of the cytosine crystal was achieved by removal of the water of crystallization in an achiral monohydrate crystal. Enantioselective C-C bond formation was realized on the surfaces of achiral single crystals based on the oriented prochirality of achiral aldehydes. Furthermore, asymmetric autocatalysis of pyrimidyl alkanols is a highly sensitive reaction that can recognize and amplify the significantly small effect of a chiral compound arising solely from isotope substitution of hydrogen, carbon, and oxygen (D/H, (13)C/(12)C, and (18)O/(16)O). These examples show that asymmetric autocatalysis with an amplification of chirality is a powerful tool for correlating the origin of chirality with highly enantioenriched organic compounds. Asymmetric autocatalysis using two β-amino alcoho...

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“…Thus, chiral crystal 1 can act as the chiral trigger of asymmetric autocatalysis to get the formation of asymmetric autocatalyst with tiny ee. Previously reported computational results 13 indicate that the enantioface-selective adsorption of pyrimidine-5-carbaldehyde 2 is followed by the i-Pr 2 Zn addition and enantioselective adsorption of the initially formed isopropylzinc alkoxide of pyrimidyl alkanol 3, which can induce an enantiomerically imbalanced asymmetric autocatalyst. Then, subsequent asymmetric autocatalysis by the consecutive addition of i-Pr 2 Zn and aldehyde 2 enhances the ee, which becomes very high (Scheme 3).…”

Section: ¹1mentioning

confidence: 99%

Enantioselective Synthesis Induced by the Helical Molecular Arrangement in the Chiral Crystal of Achiral Tris(2-hydroxyethyl) 1,3,5-Benzenetricarboxylate in Conjunction with Asymmetric Autocatalysis

et al. 2013

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5-Pyrimidyl alkanol with an enantiomeric excess of up to >99.5% was formed using chiral crystals of achiral tris(2-hydroxyethyl) 1,3,5-benzenetricarboxylate as a chiral initiator.In the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde, the helicity of the molecular arrangement of achiral tricarboxylate in the crystalline state could be successfully used as a source of chirality to afford enantioenriched alkanol in conjunction with asymmetric autocatalysis with amplification of enantiomeric excess.Spontaneous chiral crystallization of achiral compounds is suspected as a possible origin of biological homochirality such as that found in L-amino acids and D-sugars.1 There are achiral organic compounds that crystallize in chiral space groups to form enantiomorphous crystals.2 Stereospecific reactions have been reported to form enantioenriched organic compounds using enantiomorphous crystals as reactants in the solid state. 2We have been studying asymmetric autocatalysis with amplification of enantiomeric excess (ee), 36 in which a chiral product acts as the chiral catalyst for its own production. Chiral crystals formed from achiral compounds can act as the source of chirality in the addition reaction of dialkylzinc to aldehyde to give a highly enantioenriched product in combination with asymmetric autocatalysis. 7 In this process, the spontaneously generated chiral crystals of the achiral molecules induce enantioselectivity upon the organic compound, and then the asymmetric autocatalysis increases the initial tiny imbalance of chirality to afford a large amount of enantioenriched organic compound. Asymmetric autocatalysis with amplification of ee can correlate the origins of chirality with the homochirality of organic compounds. Azumaya, Yokozawa, and co-workers reported that tris(2-hydroxyethyl) 1,3,5-benzenetricarboxylate (1) formed helically arranged enantiomorphous crystals, which belong to the chiral space group P6 1 or P6 5 (Scheme 1). 9 The planar molecules 1 helically connected with neighboring molecules to generate chirality in the crystalline state by aromaticaromatic interactions and hydrogen bonds. Because the columnar stacks within individual crystals have the same sense of helicity, the crystal shows chirality.Asymmetric synthesis 10 and separation 11 using a chiral substance with helical structure 12 are an intriguing research topic in chiral chemistry. In this paper, we report on the use of chiral crystals of tricarboxylate 1 as a chiral inducer in asymmetric autocatalysis. Therefore, highly enantioenriched organic compounds can be synthesized based on the helicity of 1 in conjunction with asymmetric autocatalytic amplification of ee (Scheme 2).The enantiomorphs of 1 could be obtained by stirred crystallization from methanol solution (Scheme 1). The chirality of the crystal can be discriminated by using the solid-state circular dichroism (CD) spectrum; therefore, right-handed Pcrystals of 1 show a positive Cotton effect at 224 nm with the KBr method ([CD(+)224 KBr ]-1), while...

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Prediction of Soai Reaction Enantioselectivity Induced by Crystals ofN-(2-Thienylcarbonyl)glycine

Cited by 32 publications

References 82 publications

Mechanics of twisted hippuric acid crystals untwisting as they grow

Mechanics of twisted hippuric acid crystals untwisting as they grow

Asymmetric Autocatalysis of Pyrimidyl Alkanol and Its Application to the Study on the Origin of Homochirality

Enantioselective Synthesis Induced by the Helical Molecular Arrangement in the Chiral Crystal of Achiral Tris(2-hydroxyethyl) 1,3,5-Benzenetricarboxylate in Conjunction with Asymmetric Autocatalysis

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