A Potential Iterative Approach to 1,4-Dihydro-N-Heteroacene Arrays

Acknowledgements We are grateful to the UK EPSRC National Mass Spectrometry Service Centre for mass spectrometric data.Peer reviewedPublisher PD

APA2[Zn3(HPO4)4(H2O)2], a layered zincophosphate featuring template-to-framework N-H⋯O and "synergic" framework-to-template O-H⋯N hydrogen bonds and C-H⋯O interactions (APA = 2-Amino-1-phenyleneammonium, C6H9N2 +)

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[KDy(Hptc)3(H3ptc)]n·2n(Hbipy)·5n(H2O), a layered coordination polymer containing DyO6N3 tri-capped trigonal prisms (H3ptc = Pyridine 2,4,6-Tricarboxylic Acid, C8H5NO6; Bipy = 2,2'-Bipyridine, C10H8N2)

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Synthesis and structural features of copper(II) complexes of N,N,N′,N′-tetramethylethylenediamine with 2-chlorobenzoate1− and 2-hydroxybenzoate1−

Published online 22 Jan 2019.Peer reviewedPostprin

In Situ Template Generation for Zincophosphate Synthesis Leading to C2H7N4O-ZnPO4 Containing Template-to-Template N--H...O Hydrogen Bonds

The synthesis, structure and some properties of C{sub 2}H{sub 7}N{sub 4}O {center_dot} ZnPO{sub 4} (guanylurea zinc phosphate) are reported. The cationic template was prepared in situ by partial hydrolysis of the neutral 2-cyanoguanidine starting material. The resulting structure contains a new, unprotonated, zincophosphate layer topology as well as unusual N-H-O template-to-template hydrogen bonds which help to stabilize a ''double sandwich'' of templating cations between the inorganic sheets. Crystal data: C{sub 2}H{sub 7}N{sub 4}O {center_dot} ZnPO{sub 4}, M{sub r} = 229.44, monoclinic, P2{sub 1}/c, a = 13.6453 (9) {angstrom}, b = 5.0716 (3) {angstrom}, c = 10.6005 (7) {angstrom}, {beta} = 95.918 (2){sup 0}, V = 729.7 (1) {angstrom}{sup 3}, R(F) = 0.034, wR(F) = 0.034

3-Fluoro-4-hydroxyprolines:Synthesis, conformational analysis and stereoselective recognition by the VHL E3 ubiquitin ligase for targeted protein degradation

Hydroxylation and fluorination of proline alters the pyrrolidine ring pucker and the trans:cis amide bond ratio in a stereochemistry-dependent fashion, affecting molecular recognition of proline-containing molecules by biological systems. While hydroxyprolines and fluoroprolines are common motifs in medicinal and biological chemistry, the synthesis and molecular properties of prolines containing both modifications, i.e., fluoro-hydroxyprolines, have not been described. Here we present a practical and facile synthesis of all four diastereoisomers of 3-fluoro-4-hydroxyprolines (F-Hyps), starting from readily available 4-oxo-l-proline derivatives. Small-molecule X-ray crystallography, NMR spectroscopy, and quantum mechanical calculations are consistent with fluorination at C³ having negligible effects on the hydrogen bond donor capacity of the C⁴ hydroxyl, but inverting the natural preference of Hyp from C⁴-exo to C⁴-endo pucker. In spite of this, F-Hyps still bind to the von Hippel–Lindau (VHL) E3 ligase, which naturally recognizes C⁴-exo Hyp in a stereoselective fashion. Co-crystal structures and electrostatic potential calculations support and rationalize the observed preferential recognition for (3<i>R</i>,4<i>S</i>)-F-Hyp over the corresponding (3<i>S</i>,4<i>S</i>) epimer by VHL. We show that (3<i>R</i>,4<i>S</i>)-F-Hyp provides bioisosteric Hyp substitution in both hypoxia-inducible factor 1 alpha (HIF-1α) substrate peptides and peptidomimetic ligands that form part of PROTAC (proteolysis targeting chimera) conjugates for targeted protein degradation. Despite a weakened affinity, Hyp substitution with (3<i>S</i>,4<i>S</i>)-F-Hyp within the PROTAC MZ1 led to Brd4-selective cellular degradation at concentrations >100-fold lower than the binary <i>K</i>_d for VHL. We anticipate that the disclosed chemistry of 3-fluoro-4-hydroxyprolines and their application as VHL ligands for targeted protein degradation will be of wide interest to medicinal organic chemists, chemical biologists, and drug discoverers alike

A geomimetic synthesis of mellite : a mineral containing a benzene ring

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The isolation of N-tert-butyl-p-toluidine hydrochloride and the synthesis of mauveine

Acknowledgements We are grateful to the EPSRC national mass spectrometry service centre for mass spectra and to the trustees of the mauveine collection in MoSI for a sample of authentic mauveine.Peer reviewedPostprin

Synthesis, characterization, crystal structures and thermal and fluorescence studies of dinuclear and polymeric silver(I) complexes of 5,5-diethylbarbiturate with 2,5-dimethylpyrazine and piperazine involving Ag-Ag interactions

Two silver(I) complexes, [Ag(dmpyz)(2)][Ag(barb)(2)] (1) and {[Ag(ppz)][Ag(barb)(2)]center dot H2O} (n) (2) (barb = 5,5-diethylbarbiturate, dmpyz = 2,5-dimethylpyrazine and ppz = piperazine), have been synthesized and characterized by elemental analyses, IR, thermal analysis (TG-DTA) and single-crystal X-ray diffraction. Complex 1 consists of [Ag(dmpyz)(2)](+) and [Ag(barb)(2)](-) ions in which the silver(I) ions are linearly coordinated by two dmpyz or two barb ligands. These two ions are connected by strong Ag-Ag interactions (Ag-Ag = 2.896 (1) ). Complex 2 is a 1D coordination polymer in which the silver(I) ions are bridged by the ppz ligands in a linear fashion, leading to a zigzag chain of [Ag(ppz)] (n) (+) , which interacts with the [Ag(barb)(2)](-) units by Ag-Ag interactions of 3.183 (1) . The 1D chains are further assembled to form 3D networks by strong N-H center dot center dot center dot O and OW-H center dot center dot center dot O hydrogen bonds. IR spectra and TG-DTA data are in agreement with the crystal structures. The fluorescent properties of 1 were also evaluated