Introduced to the Market in the Last Decade (2001−2011) Jiang Wang,† María Sańchez-Rosello,́‡,§ Jose ́ Luis Aceña, Carlos del Pozo,‡ Alexander E. Sorochinsky, Santos Fustero,*,‡,§ Vadim A. Soloshonok,* and Hong Liu*,† †Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China ‡Department of Organic Chemistry, Faculty of Pharmacy, University of Valencia, Av. Vicente Andreś Estelleś, 46100 Burjassot, Valencia, Spain Laboratorio de Molećulas Orgańicas, Centro de Investigacioń Príncipe Felipe, C/ Eduardo Primo Yuf́era 3, 46012 Valencia, Spain Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel Lardizab́al 3, 20018 San Sebastian, Spain IKERBASQUE, Basque Foundation for Science, Alameda Urquijo, 36-5 Plaza Bizkaia, 48011 Bilbao, Spain Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Murmanska Street 1, 02660 Kyiv-94, Ukraine

Fluorine in pharmaceutical industry: fluorine-containing drugs introduced to the market in the last decade (2001-2011).

Asymmetric enamine catalysis.

An essential step in macromolecular refinement is the selection of model parameters which give as good a description of the experimental data as possible while retaining a realistic data-to-parameter ratio. This is particularly true of the choice of atomic displacement parameters, where the move from individual isotropic to individual anisotropic refinement involves a sixfold increase in the number of required displacement parameters. The number of refinement parameters can be reduced by using collective variables rather than independent atomic variables and one of the simplest examples of this is the TLS parameterization for describing the translation, libration and screw-rotation displacements of a pseudo-rigid body. This article describes the implementation of the TLS parameterization in the macromolecular refinement program REFMAC. Derivatives of the residual with respect to the TLS parameters are expanded in terms of the derivatives with respect to individual anisotropic U values, which in turn are calculated using a fast Fourier transform technique. TLS refinement is therefore fast and can be used routinely. Examples of TLS refinement are given for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a transcription activator GerE, for both of which there is data to only 2.0 A, so that individual anisotropic refinement is not feasible. GAPDH has been refined with between one and four TLS groups in the asymmetric unit and GerE with six TLS groups. In both cases, inclusion of TLS parameters gives improved refinement statistics and in particular an improvement in R and free R values of several percent. Furthermore, GAPDH and GerE have two and six molecules in the asymmetric unit, respectively, and in each case the displacement parameters differ significantly between molecules. These differences are well accounted for by the TLS parameterization, leaving residual local displacements which are very similar between molecules and to which NCS restraints can be applied.

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Use of TLS parameters to model anisotropic displacements in macromolecular refinement

Hydrogenation is a core technology in chemical synthesis. High rates and selectivities are attainable only by the coordination of structurally well-designed catalysts and suitable reaction conditions. The newly devised [RuCl(2)(phosphane)(2)(1,2-diamine)] complexes are excellent precatalysts for homogeneous hydrogenation of simple ketones which lack any functionality capable of interacting with the metal center. This catalyst system allows for the preferential reduction of a C=O function over a coexisting C=C linkage in a 2-propanol solution containing an alkaline base. The hydrogenation tolerates many substituents including F, Cl, Br, I, CF(3), OCH(3), OCH(2)C(6)H(5), COOCH(CH(3))(2), NO(2), NH(2), and NRCOR as well as various electron-rich and -deficient heterocycles. Furthermore, stereoselectivity is easily controlled by the electronic and steric properties (bulkiness and chirality) of the ligands as well as the reaction conditions. Diastereoselectivities observed in the catalytic hydrogenation of cyclic and acyclic ketones with the standard triphenylphosphane/ethylenediamine combination compare well with the best conventional hydride reductions. The use of appropriate chiral diphosphanes, particularly BINAP compounds, and chiral diamines results in rapid and productive asymmetric hydrogenation of a range of aromatic and heteroaromatic ketones and gives a consistently high enantioselectivity. Certain amino and alkoxy ketones can be used as substrates. Cyclic and acyclic alpha,beta-unsaturated ketones can be converted into chiral allyl alcohols of high enantiomeric purity. Hydrogenation of configurationally labile ketones allows for the dynamic kinetic discrimination of diastereomers, epimers, and enantiomers. This new method shows promise in the practical synthesis of a wide variety of chiral alcohols from achiral and chiral ketone substrates. Its versatility is manifested by the asymmetric synthesis of some biologically significant chiral compounds. The high rate and carbonyl selectivity are based on nonclassical metal-ligand bifunctional catalysis involving an 18-electron amino ruthenium hydride complex and a 16-electron amido ruthenium species.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/1521-3773%2820010105%2940%3A1%3C40%3A%3AAID-ANIE40%3E3.0.CO%3B2-5

Asymmetric Catalysis by Architectural and Functional Molecular Engineering: Practical Chemo‐ and Stereoselective Hydrogenation of Ketones

This review describes a multidimensional treatment of molecular recognition phenomena involving aromatic rings in chemical and biological systems. It summarizes new results reported since the appearance of an earlier review in 2003 in host-guest chemistry, biological affinity assays and biostructural analysis, data base mining in the Cambridge Structural Database (CSD) and the Protein Data Bank (PDB), and advanced computational studies. Topics addressed are arene-arene, perfluoroarene-arene, S⋅⋅⋅aromatic, cation-π, and anion-π interactions, as well as hydrogen bonding to π systems. The generated knowledge benefits, in particular, structure-based hit-to-lead development and lead optimization both in the pharmaceutical and in the crop protection industry. It equally facilitates the development of new advanced materials and supramolecular systems, and should inspire further utilization of interactions with aromatic rings to control the stereochemical outcome of synthetic transformations.

Aromatic rings in chemical and biological recognition: energetics and structures.

On the validity of Wallach's rule: on the density and stability of racemic crystals compared with their chiral counterparts

Structure elucidation of hexabromocyclododecanes—a class of compounds with a complex stereochemistry

The structures of the crystalline lithium enolates derived from 3, 3-dimethyl-2-butanone and from cyclopentanone have been determined by X-ray analysis. Both structures are tetrameric aggregates based on a Li4O4-cube, each Li+-ion being additionally bonded to the O-atom of a tetrahydrofuran solvent molecule.

Tetrameric Cubic Structures of Two Solvated Lithium Enolates

Crystal structure analyses have been carried out for lithium enolates of the following three esters: tert-butyl propionate ((Z)-1), tert-butyl2-methylpropionate (2), and methyl 3,3-dimethylbutanoate ((Z)-3). Enolates (Z)-1 and 2 are dimeric (with one TMEDA per Li atom), whereas (2)-3 is tetrameric (with one THF per Li atom). The Z configuration of 1 and 3 established by X-ray analysis is in agreement with that assigned by Ireland. From a detailed analysis of the geometry of the ester enolate grouping, the reaction path trajectory for the breakdown of this type of molecule can be derived. The implication of ketenes as intermediates, suggested by this analysis, could be confirmed chemically. In spite of the central importance of ester enolates as reactive intermediates in synthetic organic chemistry, very little is known about the actual structures of the metallated species involved. This lack of information is largely attributable to the low stability of ester enolates in general. In fact, the structures of only two metal derivatives of esters have been established by X-ray analysis: one is the Reformatksy reagent derived from tert-butyl bromoacetate,2 and the other is a lithium derivative of the highly acidic penta- kis(methoxycarbonyl)cyclopentadiene.3 Neverthless, it has been more than 10 years since the Lochmann4 and Rathke5 groups described the isolation of pure lithium derivatives of esters as solid substances. The analysis of these compounds was at that time limited to what could be achieved by IR and NMR spectroscopy; the deduction was that they are to be formulated as enolates. Deprotonation of esters of the type RR'CH-COOR" with LDA (lithium diisopropylamide) gives in principle (E)- or (Z)-con- figurated enolates, shown as (E)-1 and (Z)-1 for the example of

Structures of Three Lithium Ester Enolates by X-ray Diffraction: Derivation of Reaction Path for Cleavage into Ketene and Alcoholate'

Dergauche-Effekt, der bei der reversiblen Bildung eines Iminiumions (siehe Struktur: F grun, N blau) auftritt, bietet eine nutzliche Moglichkeit, die raumliche Ausrichtung von Intermediaten in durch sekundare Amine katalysierten Reaktionen zu steuern. Dieses Phanomen wurde beim Entwurf eines neuartigen Organokatalysators genutzt und bei der stereoselektiven Epoxidierung von α,β-ungesattigten Aldehyden angewendet.

W. Bernd Schweizer

Papers

On the validity of Wallach's rule: on the density and stability of racemic crystals compared with their chiral counterparts

Structure elucidation of hexabromocyclododecanes—a class of compounds with a complex stereochemistry

Tetrameric Cubic Structures of Two Solvated Lithium Enolates

Structures of Three Lithium Ester Enolates by X-ray Diffraction: Derivation of Reaction Path for Cleavage into Ketene and Alcoholate'

The Fluorine‐Iminium Ion Gauche Effect: Proof of Principle and Application to Asymmetric Organocatalysis