Stereoselective addition of acetone to the C=N bond of [4.3.0] boron heterobicycles

2001 ◽  
Vol 79 (8) ◽  
pp. 1229-1237 ◽  
Author(s):  
Victor Barba ◽  
Damian Cuahutle ◽  
Rosa Santillan ◽  
Norberto Farfán
Keyword(s):  
Solid State ◽  
Schiff Bases ◽  
Boronic Acid ◽  
Boronic Acids ◽  
Tridentate Ligands ◽  
X Ray ◽  
Dimeric Structure ◽  
Stereoselective Addition ◽  
Phenyl Boronic Acid ◽  
Boron Complexes

The reaction of N-salicylidene-2-aminophenolate (SAP-H2) derivatives with phenyl boronic acid afforded five new boron bicyclic species in moderate yields, as confirmed by an X-ray study of the boron heterocycle derived from 2-amino-4-chlorophenol. The results also showed that the boron complexes derived from Schiff bases undergo an acetolysis reaction to give the corresponding dioxazaborocines containing all substituents on the same side also in good yields. The structure of one of the addition products was established by X-ray analysis showing that, in the solid state, it exists as a dimeric structure formed by hydrogen bonds.Key words: borocines, tridentate ligands, imines, boronic acids.

High solid-state luminescence in propeller-shaped AIE-active pyridine–ketoiminate–boron complexes

2015 ◽  
Vol 13 (20) ◽  
pp. 5775-5782 ◽  
Author(s):  
Yanping Wu ◽  
Zhenyu Li ◽  
Qingsong Liu ◽  
Xiaoqing Wang ◽  
Hui Yan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Solid State ◽  
Quantum Yield ◽  
Stokes Shift ◽  
Electronic Structure Calculations ◽  
High Quantum Yield ◽  
X Ray ◽  
Boron Complexes ◽  
Structure Calculations ◽  
State Luminescence

Two pyridine-ketoiminate-based organoboron complexes were demonstrated to possess aggregation-induced emission, large Stokes shift and high quantum yield in the solid-state, which were rationalized through X-ray crystal analysis and electronic structure calculations.

The Structural Basis for Hydrolysis Resistance in the Esters of (2-Formylphenyl)boronic Acid 2,4-Dinitrophenylhydrazones

2002 ◽  
Vol 67 (7) ◽  
pp. 1084-1094 ◽  
Author(s):  
Michael P. Groziak ◽  
Paul D. Robinson
Keyword(s):  
Boronic Acid ◽  
Intramolecular Interaction ◽  
Boronic Acids ◽  
Membered Ring ◽  
Structural Basis ◽  
Previous Suggestion ◽  
Boronate Esters ◽  
X Ray ◽  
Hydrolysis Resistance ◽  
Electron Deficiency

Under conditions that typically afford bicyclic boron heterocycles directly, (2-formylphenyl)boronic acids react with 2,4-dinitrophenylhydrazine in ethanol to give highly waterresistant diethyl boronate esters. Two such 2,4-dinitrophenylhydrazones were prepared and their X-ray crystal structures determined. Contrary to a previous suggestion that their unusual stability is due to an intramolecular N→B coordination giving a six-membered BN2C3 ring system based on a (Z)-hydrazone, these compounds instead were found to be (E)-hydrazones internally stabilized by a weak intramolecular interaction between nitrogen and boron from within a five-membered ring. Further study revealed that the electron deficiency of the starting hydrazine reagent plays a key role in determining the structure of the hydrazone isolated, and that the water-resistant boronate esters can be hydrolyzed under forcing conditions to the boronic acids.

Metal Complexes of Biologically Important Ligands, CLXXIV [1]. Palladium(II) and Platinum(II) Complexes with Schiff Bases from 2-(Diphenylphosphino)benzaldehyde and α-Amino Acid Esters

2010 ◽  
Vol 65 (4) ◽  
pp. 503-510 ◽  
Author(s):  
Bernhard Schreiner ◽  
Christian Robl ◽  
Barbara Wagner-Schuh ◽  
Wolfgang Beck
Keyword(s):  
Schiff Base ◽  
Amino Acid ◽  
Schiff Bases ◽  
Ester Group ◽  
Amino Acid Esters ◽  
X Ray Diffraction ◽  
Tridentate Ligands ◽  
X Ray ◽  
Reduced Schiff Base ◽  
Acid Esters

A series of palladium(II) and platinum(II) complexes Cl2M(P-N-O) (M = Pd, Pt) with bidentate Schiff bases (P-N-O) from 2-(diphenylphosphino)benzaldehyde and α-amino acid esters has been synthesized, using PdCl2 or K[PtCl3(C2H4)], respectively. Abstraction of chloride from Cl2M(P-N-O) (using AgBF4) has afforded the cationic complexes [(P-N-O)M(Cl)]+BF4− in which the Schiff bases function as tridentate ligands with coordination of the ester group. The structures of Cl2Pd(Ph2PC6H4C(H)=N-CH2CO2Et) and of [(Cl)Pd(Ph2PC6H4C(H)=NC(H)(CH2CH=CH2)CO2Me)]+BF4− have been determined by X-ray diffraction. Complexes (L)MCl2 and [(L)MCl]+BF4 (M = Pd, Pt) have also been prepared with the reduced Schiff base Ph2PC6H4CH2NHC(H)(CH2Ph)CO2Me.

scholarly journals A mechanistic proposal for the protodeboronation of neat boronic acids: boronic acid mediated reaction in the solid state

2015 ◽  
Vol 13 (9) ◽  
pp. 2555-2560 ◽  
Author(s):  
Gary Noonan ◽  
Andrew G. Leach
Keyword(s):  
Solid State ◽  
Boronic Acid ◽  
Boronic Acids

Boronic acids that undergo protodeboronation as solids are stable in solution: the solid state organizes them for reaction.

ChemInform Abstract: Tautomerism in Schiff Bases Derived from 3-Hydroxysalicylaldehyde (I). Combined X-Ray Diffraction, Solution and Solid State NMR Study.

ChemInform ◽  
2010 ◽  
Vol 31 (32) ◽  
pp. no-no
Author(s):  
Helene Pizzala ◽  
Micheline Carles ◽  
William E. E. Stone ◽  
Andre Thevand
Keyword(s):  
Solid State ◽  
Schiff Bases ◽  
Solid State Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Study

scholarly journals (1,3-Diethyl-1,3-dihydro-4,5-dimethyl- 2H -imidazol-2-yliden)-diiodtellur(II) [1]

1996 ◽  
Vol 51 (2) ◽  
pp. 295-297 ◽  
Author(s):  
Norbert Kuhn ◽  
Thomas Kratz ◽  
Gerald Henkel
Keyword(s):  
Solid State ◽  
Structure Analysis ◽  
X Ray ◽  
Dimeric Structure

Abstract The carbene adduct 5 is formed from the 2-tel-luroimidazoline 4 and iodine. The X-ray structure analysis reveals a dimeric structure in the solid state.

A Solid State Study of Keto-enol Tautomerismin Three Naphthaledene Schiff Bases

2012 ◽  
Vol 65 (5) ◽  
pp. 552 ◽  
Author(s):  
Gregory K. Pierens ◽  
T. K. Venkatachalam ◽  
Paul V. Bernhardt ◽  
Mark J. Riley ◽  
David C. Reutens
Keyword(s):  
Solid State ◽  
Absorption Band ◽  
Schiff Bases ◽  
Variable Temperature ◽  
Colour Change ◽  
Uv Spectra ◽  
X Ray ◽  
X Ray Crystallography ◽  
State Study ◽  
Tautomeric Composition

Three naphthaledene Schiff bases were synthesized and a detailed analysis by variable temperature X-ray crystallography and solid state electronic spectra was undertaken to assess the tautomeric composition. The crystal structures showed no significant changes despite the compounds changing colour with temperature. Solid state UV spectra were acquired at low temperature and showed that the major absorption band broadened as the temperature was increased. In one compound absorptions were observed that increased in intensity as the temperature increased. For these compounds, the major contribution to the colour change is the broadening of the absorption band as a function of temperature and not the change in enol-keto tautomeric composition.

A molecular roundabout: triple cyclically arranged hydrogen bonds in light of experiment and theory

2018 ◽  
Vol 42 (24) ◽  
pp. 19467-19477 ◽  
Author(s):  
Agnieszka Kwocz ◽  
Jarosław Jan Panek ◽  
Aneta Jezierska ◽  
Łukasz Hetmańczyk ◽  
Andrzej Pawlukojć ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Schiff Bases ◽  
Dft Studies ◽  
X Ray

This paper dwells on the synthesis and diverse studies of cyclically arranged hydrogen bridges in tris-hydroxy aryl Schiff bases. Experimental (IINS, IR, Raman and X-ray) and theoretical (CPMD, DFTP and DFT) studies of tris-hydroxy aryl Schiff bases have been performed in the solid state.

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