Author
Yuri T. Struchkov
Other affiliations: Russian Academy of Sciences, Technion – Israel Institute of Technology
Bio: Yuri T. Struchkov is an academic researcher from A. N. Nesmeyanov Institute of Organoelement Compounds. The author has contributed to research in topics: Crystal structure & Schiff base. The author has an hindex of 22, co-authored 71 publications receiving 1354 citations. Previous affiliations of Yuri T. Struchkov include Russian Academy of Sciences & Technion – Israel Institute of Technology.
Papers
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TL;DR: In this article, the chiral NiII complex 1 of a Schiff's base derived from (S)-o-[N-(benzylprolyl)amino] benzophenone (BPB) and glycine was treated with fluoro-substituted aldehydes (aliphatic and aromatic) in MeOH or CHCl3.
Abstract: The chiral NiII complex 1 of a Schiff's base derived from (S)-o-[N-(N-benzylprolyl)amino] benzophenone (BPB) and glycine was treated with fluoro-substituted aldehydes (aliphatic and aromatic)in MeOH or CHCl3. The addition proceeds with high diastereoselectivity to give, if catalysed by MeONa in MeOH, the corresponding complexes of syn-(2R)-3-fluorophenylserines (84–100% d.e.) and syn-(2S)-fluoroalkylserines (90% d.e.), and, if catalysed by NEt3 or DABCO (MeOH or CHCl3), the corresponding complexes of syn-(2S)-, and anti-(2S)-3-fluorophenylserines and fluoroalkylserines. The second-order asymmetric transformation may be successfully employed to obtain diastereoisomerically pure complexes of anti-(2R)-3-fluorophenylserines. Condensation of trifluoroacetone with complex 1, catalysed by MeONa, gave predominantly (at least >95% d.e.) the diastereoisomeric complex, containing (2S,3S)-β-(trifluoromethyl)threonine, as shown by an X-ray diffraction structural study. Diastereoisomerically and enantiomerically pure fluorine-containing 3-phenyl- and 3-alkyl-serines were obtained from the corresponding diastereoisomerically pure complexes, separated by chromatography or crystallization. The initial chiral auxiliary BPS was recovered (80–98%). The influence of the reaction's conditions and the nature of the corresponding fluoro-substituted aldehydes on the diastereoselectivity of the reactions is discussed.
88 citations
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TL;DR: In this paper, a novel class of coordination compounds, polymetallaorganosiloxanolates (PMOS) {SiPh(O)-O} n− n M 1 2 n−x 2+ Na n (M = Mn, Co, Ni, Cu), whose structure was elucidated by an X-ray diffraction study.
84 citations
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TL;DR: In this paper, aldol reactions between aliphatic aldehydes and Ni(II)-complex of chiral non-racemic Schiff base of glycine with (S )- o -[ N -( N -benzylprolyl)amino]benzophenone (BPB) in the presence of excess of MeONa, has been studied as a function of time, reaction conditions and nature of an aldehyde.
Abstract: Stereoselectivity of aldol reactions between aliphatic aldehydes and Ni(II)-complex of chiral non-racemic Schiff base of glycine with ( S )- o -[ N -( N -benzylprolyl)amino]benzophenone (BPB) in the presence of excess of MeONa, has been studied as a function of time, reaction conditions and nature of an aldehyde. Two salient features of the reaction, very high pseudokinetic syn -(2 S )-diastereoselectivity, and dependence of thermodynamic syn -(2 R )-diastereoselectivity on the steric bulk of an aldehyde side chain, were disclosed and used for efficient (more than 90% de and ee) asymmetric synthesis of both syn -(2 S ) and syn -(2 R )-3-alkyl substituted serines. Synthetic potential and reliability of this asymmetric method are demonstrated with the large scale (2–20 g) preparation of enantiomerically pure amino acids.
82 citations
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TL;DR: In this article, a series of 1,4-disubstituted 2,3-dicyano-5,6-dichlorobenzenes and related compounds are constructed with polarization-induced C ≡ N···Cl interactions.
Abstract: Supramolecular synthons in crystals are structural units formed with intermolecular interactions. The assembly of an organic crystal is not just a geometrical interlinking with synthons but is often the consequence of compromise or mutual interference between adjacent synthons. Accordingly, synthon interference can be a major problem in systematic crystal engineering especially if it results in a lack of correspondence between molecular and crystal structures. Conversely, synthon robustness or the capacity to withstand interference is an essential attribute in crystal structure design. These ideas are illustrated with reference to the structural chemistry of a series of 1,4-disubstituted 2,3-dicyano-5,6-dichlorobenzenes and related compounds. The supramolecular synthons in this structural family are constructed with polarization-induced C ≡ N···Cl interactions. Synthon interference is analyzed in terms of the trade-off between these interactions on the one hand and hydrophobic and CH···N interactions on the other. Topological relationships between these C ≡ N···Cl synthons and others containing stronger hydrogen bond interactions lead to similarities in the networks formed in the crystal structures of compounds, which at the molecular level, are widely disparate.
74 citations
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TL;DR: The hexanuclear complex rhenium salt Cs3K[Re6(μ3-S)6 (μ3)-Te 0.66S 0.34)2(CN)6] ({Bd1}) has been prepared by the reaction of Re6Te15 with molten KSCN and subsequent treatment with an aqueous solution of CsCl as discussed by the authors.
68 citations
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TL;DR: In this Perspective, applications of fluorine in the construction of bioisosteric elements designed to enhance the in vitro and in vivo properties of a molecule are summarized.
Abstract: The electronic properties and relatively small size of fluorine endow it with considerable versatility as a bioisostere and it has found application as a substitute for lone pairs of electrons, the hydrogen atom, and the methyl group while also acting as a functional mimetic of the carbonyl, carbinol, and nitrile moieties. In this context, fluorine substitution can influence the potency, conformation, metabolism, membrane permeability, and P-gp recognition of a molecule and temper inhibition of the hERG channel by basic amines. However, as a consequence of the unique properties of fluorine, it features prominently in the design of higher order structural metaphors that are more esoteric in their conception and which reflect a more sophisticated molecular construction that broadens biological mimesis. In this Perspective, applications of fluorine in the construction of bioisosteric elements designed to enhance the in vitro and in vivo properties of a molecule are summarized.
1,199 citations
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952 citations
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TL;DR: The key unifying feature of almost all molecules discussed in this review is that they are generally stabilized by the use of bulky substituents which block associative or various decomposition pathways.
Abstract: This review is essentially an update of one entitled “πBonding and The Lone Pair Effect in Multiple Bonds Between Heavier Main Group Elements” which was published more than 10 years ago in this journal.1 The coverage of that survey was focused on the synthesis, structure, and bonding of stable compounds2 of heavier main group elements that correspond to the skeletal drawings reproduced in Tables 1 and 2. A row of numbers is listed at the bottom of each column in these tables. This refers to the number of stable complexes from each class that are currently known. The numbers in parentheses refer to the number of stable species that were known at the time of the previous review. Clearly, many of the compound classes listed have undergone considerable expansion although some remain stubbornly rare. The most significant developments for each class will be discussed in detail under the respective sections. As will be seen, there are also a limited number of multiple bonded heavier main group species that do not fit neatly in the classifications in Tables 1 and 2. However, to keep the review to a manageable length, the limits and exclusions, which parallel those used earlier, are summarized as follows: (i) discussion is mainly confined to compounds where experimental data on stable, isolated species have been obtained, (ii) stable compounds having multiple bonding between heavier main group elements and transition metals are not generally discussed, (iii) compounds in which a multiple bonded heavier main group element is incorporated within a ring are generally not covered, and (iv) hypervalent main group compounds that may incorporate faux multiple bonding are generally excluded. Such compounds are distinguished from those in Tables 1 and 2 in that they apparently require the use of more than four valence bonding orbitals at one or more of the bonded atoms. The remainder of this review is organized in a similar manner to that of the previous one wherein the compounds to be discussed are classified according to those summarized in Tables 1 and 2. The key unifying feature of almost all molecules discussed in this review is that they are generally stabilized by the use of bulky substituents which block associative or various decomposition pathways.3 Since the previous review was published in 1999, several review articles that cover parts of the subject matter have appeared.4
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