Fixed stereochemical control in the synthesis of new mono- and disubstituted 2-phenyl-6-aza-1,3-dioxa-2-borabenzocyclononenes

Beltrán, Hiram I; Alas, S Jesús; Santillan, Rosa; Farfán, Norberto
July 2002
Canadian Journal of Chemistry;Jul2002, Vol. 80 Issue 7, p801
Academic Journal
Five new boronates of the type 2-phenyl-6-aza-1,3-dioxa-2-borabenzocyclononenes (6a–e) were prepared from substituted 2-[(2-hydroxyethylamino)methyl]phenols (4a–e) and phenylboronic acid (5) in benzene-EtOH (4:1) mixtures. Tridentate ligands 4a–e and boronates 6a–e were characterized by [sup 1] H, [sup 13] C, [sup 15] N, and 2D-NMR (HETCOR, NOESY, and COLOC) experiments, FT-IR, mass spectra, and elemental analysis, as well as [sup 11] B NMR for the boron derivatives. Suitable monocrystals of 2-[(2-hydroxyethylamino)methyl]phenol hydrochloride (4a), cis-2-phenyl-6-aza-1,3-dioxa-2-borabenzocyclononene (6a), (2S,5R,6S)-2,5-diphenyl-6-aza-1,3-dioxa-2-borabenzocyclononene (6b), and (2S,4R,5R,6S)-2,4-diphenyl-5-methyl-6-aza-1,3-dioxa-2-borabenzocyclononene (6e) were obtained and their structures are discussed. The X-ray structures of 6a, 6b, and 6e, as well as the NMR data established that the configurations at the nitrogen and boron atoms are both "S" and the transannular fusion is cis. A semi-empirical (SAM1) study was used to calculate the energy for all possible stereoisomers, showing that the stabilization increases as the THC (tetrahedral character of the boron atom) increases and also as the NB bond distance decreases, in agreement with the experimental results and previous work related to amino acid boronates.Key words: boron compounds, X-ray structures, NMR, boronates, synthesis.On a préparé cinq nouveaux boronates du type 2-phényl-6-aza-1,3-dioxa-2-borabenzocyclononènes (6a–e) en faisant réagit des 2-[(2-hydroxyéthylamino)méthyl]phénols substitués (4a–e) avec de l'acide phénylboronique (5) dans des mélanges 4:1 de benzène-éthanol. Les ligands tridentates (4a–e) et les boronates (6a–e) ont été caractérisés par les analyses élémentaires, par infrarouge à transformée de Fourier, par des expériences de RMN du [sup 1] H, du [sup 13] C, du [sup 15] N et par RMN-2D (HETCOR, NOESY et COLOC) ainsi que par RMN du [sup 11] B pour les dérivés du bore. On a obtenu des monocristaux appropriés du chlorhydrate du 2-[(2-hydroxyéthylamino)méthyl]phénol (4a), du cis-2-phényl-6-aza-1,3-dioxa-2-borabenzocyclononène (6a), du (2S,5R,6S)-2,5-diphényl-6-aza-1,3-dioxa-2-borabenzocyclononène (6b) et du (2S,4R,5R,6S)-2,4-diphényl-5-méthyl-6-aza-1,3-dioxo-2-borabenzo-cyclononène (6e) et on discute de leurs structures. Les structures des composés 6a, 6b et6e déterminées par diffraction des rayons-X ainsi que les données de la RMN ont permis d'établir que les configurations au niveau des atomes d'azote et du bore sont toutes les deux S et que la fusion transannulaire est cis. On a fait appel à des calculs semi-empiriques (SAM1) pour calculer l'énergie des tous les stéréoisomères possibles; ils montrent que la stabilisation augmente avec une augmentation du caractère tétraédrique de l'atome de bore ainsi qu'avec une diminution de la longueur de la distance NB, en accord avec les données expérimentales obtenues ici et avec celles obtenues dans un travail antérieur sur des boronates apparentés d'acides aminés.Mots clés : composés du bore, structures par diffraction des rayons X, RMN, boronates, synthèse.[Traduit par la Rédaction]


Related Articles

  • Immobilization of Lysozyme on Cotton Fabrics: Synthesis, Characterization, and Activity. Edwards, J. Vincent; Prevost, Nicolette; Condon, Brian; Sethumadhavan, Kandan; Ullah, Jaffor; Bopp, Alvin // AATCC Review;May/Jun2011, Vol. 11 Issue 3, p73 

    Lysozyme was attached to three cotton fabrics through a glycine amino acid linker esterified to cotton cellulose. Lysozyme bound to cotton twill using a carbodiimide-mediated coupling reaction gave the best lysozyme incorporation (16.1 mg/g of cotton). Cotton spunlace nonwoven fabric bound...

  • Matrix isolation Fourier transform infrared spectroscopic study of energetic nitrogen fluxes... Khabashesku, V.N.; Margrave, J.L.; Waters, K.; Schultz, J. A. // Journal of Applied Physics;8/15/1997, Vol. 82 Issue 4, p1921 

    Studies the formation of stable molecules and reactive transient species resulting from the energetic nitrogen atoms with a residual background of H2O and hydrogen in cryogenic solid N2 matrices at temperatures of 12-27 K by Fourier Transform Infrared spectroscopy. Bombardment of the...

  • Superhard self-lubricating AlMgB[sub 14] films for microelectromechanical devices. Tian, Y.; Bastawros, A.F.; Lo, C.C.H.; Constant, A.P.; Russell, A.M.; Cook, B.A. // Applied Physics Letters;10/6/2003, Vol. 83 Issue 14, p2781 

    Performance and reliability of microelectromechanical system (MEMS) components can be enhanced dramatically through the incorporation of protective thin-film coatings. Current-generation MEMS devices prepared by the lithographie-galvanoformung-abformung (LIGA) technique employ transition metals...

  • Rapid analysis of taurine in energy drinks using amino acid analyzer and Fourier transform infrared (FTIR) spectroscopy as basis for toxicological evaluation. S. Triebel; C. Sproll; H. Reusch; R. Godelmann; D. W. Lachenmeier // Amino Acids;Sep2007, Vol. 33 Issue 3, p451 

    Summary.  So-called energy drinks with very high amounts of taurine (up to 4000 mg/l are usually granted by certificates of exemption) are increasingly offered on the market. To control the currently valid maximum limits of taurine in energy drinks, a simple and rapid analytical...

  • Biodegradable Copoly(Amino Acid)s Based on 6-Aminocaproic Acid and l-Leucine. Weipeng Zhang; Yanqin Huang // Journal of Polymers & the Environment;Mar2011, Vol. 19 Issue 1, p177 

    Biodegradable copoly(amino acid)s based on 6-aminocaproic acid and l-leucine were prepared by melt condensation polymerization and characterized by Fourier transform infrared spectrometry (FTIR), proton nuclear magnetic resonance spectrometry (H NMR), and X-ray diffraction (XRD). The intrinsic...

  • Infrared spectroscopic characterization of copper–polyhistidine from 1,800 to 50 cm−1: model systems for copper coordination. El Khoury, Youssef; Hellwig, Petra // Journal of Biological Inorganic Chemistry;Jan2009, Vol. 14 Issue 1, p23 

    Poly( l-histidine) and imidazole in the presence of copper cations have been investigated by means of Fourier transform infrared (IR) spectroscopy in the mid- and far-IR spectral range to establish specific marker bands of the copper-coordination site in metalloproteins as a function of pH as...

  • Hydration of amino acids: FTIR spectra and molecular dynamics studies. Panuszko, Aneta; Adamczak, Beata; Czub, Jacek; Gojło, Emilia; Stangret, Janusz // Amino Acids;Nov2015, Vol. 47 Issue 11, p2265 

    The hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in HO. The difference spectra procedure and the chemometric method have been applied to remove the...

  • Research on Properties of Reconstituted Bamboo Lumber Made by Thermo-Treated Bamboo Bundle Curtains. Qin Li; Yu Wen-ji; Yu Yang-lun // Forest Products Journal;Jul/Aug2012, Vol. 62 Issue 7/8, p545 

    Untreated and 160℃, 180℃, and 200℃ thermo-treated bamboo bundle curtains were reconstructed to make high-density board by impregnation with phenol-formaldehyde resin. The physical and mechanical properties of the boards were examined to evaluate the effect of temperature on...

  • Synthesis and Properties of Novel Phenolic Resin Grafted Hydrolyzed Polyacrylonitrile Copolymer as Fluid-loss-control Additive. Zhilei Zhang; Yihe Zhang; Fengshan Zhou; Wangshu Tong; Xianghai Meng; Qian Zhang; Zilin Meng // Applied Mechanics & Materials;2014, Issue 513-517, p117 

    A copolymer was prepared by grafted a novel phenolic resin to hydrolyzed polyacrylonitrile as fluid-loss-control additive. The novel phenolic resin used Bisphenol A residues as raw materials. Results of Fourier transform infrared spectroscopy (FTIR) showed that the two polymers were grafted into...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics