scholarly journals Methylene: The Linker of Two Aromatic Iminium Salts

2019 ◽  
Vol 63 (3) ◽  
Author(s):  
Anurag Noonikara-Poyil ◽  
Enrique Barragan ◽  
Siddappa Patil ◽  
Alejandro Bugarin
Keyword(s):  
Structure Analysis ◽  
Bond Activation ◽  
X Ray ◽  
Full Characterization ◽  
Iminium Salts ◽  
Trimethyl Benzene ◽  
Synthetic Procedure ◽  
Chlorine Bond

A straightforward synthesis of aromatic iminium salts has been developed by coupling 2-Azido-1,3,5-trimethyl benzene with 1,3-ditert-butylimidazolium tetrafluoroborate in basic conditions, followed by treatment with dichloromethane or iodomethane. Herein, we report the synthetic procedure and full characterization data, including X-ray structure analysis, of the expected bis(triazenyl)methane adduct 5. Moreover, we have discovered what constitutes a double carbon-chlorine bond activation.

Nitrations of 3,5-Dichloro-2,4,6-trimethylphenol and 1,3,5-Trichloro-2,4,6-trimethyl-benzene; acyloin rearrangement studies of some 2,5-dinitrocyclohex-3-enones;X-ray crystal structure of 1-Acetyl-3,t-5-dichloro-c-2,4-dimethyl-2,5-dinitrocyclopent-3-en-r-1-ol

1983 ◽  
Vol 36 (1) ◽  
pp. 67 ◽  
Author(s):  
AH Clemens ◽  
MP Hartshorn ◽  
KE Richards ◽  
WT Robinson ◽  
KH Sutton ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
X Ray ◽  
Trimethyl Benzene

Nitration of dichloromesitol (11) or 1,3,5-trichloro-2,4,6-trimethylbenzene (1) gives the 6-hydroxy- 2,5-dinitrocyclohex-3-enones (12) and (13). Acyloin rearrangements of these and related substituted 6-hydroxy-2,5-dinitrocyclohex-3-enones (9), (10), (14a) and (14b) are reported, together with the X-ray crystal structure analysis of the trans-dinitro cyclopentenol derivative (24). Some stereochemical features of these acyloin rearrangements are discussed.

scholarly journals m-Carborane as a Novel Core for Periphery-Decorated Macromolecules

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2814 ◽  
Author(s):  
Ines Bennour ◽  
Francesc Teixidor ◽  
Zsolt Kelemen ◽  
Clara Viñas
Keyword(s):  
Surface Analysis ◽  
Hirshfeld Surface ◽  
X Ray Diffraction ◽  
Electrophilic Reaction ◽  
X Ray ◽  
Full Characterization ◽  
New Class ◽  
Synthetic Procedure ◽  
Judicious Choice

Closo m-C2B10H12 can perform as a novel core of globular periphery-decorated macromolecules. To do this, a new class of di and tetrabranched m-carborane derivatives has been synthesized by a judicious choice of the synthetic procedure, starting with 9,10-I2-1,7-closo-C2B10H10. The 2a-NPA (sum of the natural charges of the two bonded atoms) value for a bond, which is defined as the sum of the NPA charges of the two bonded atoms, matches the order of electrophilic reaction at the different cluster bonds of the icosahedral o-and m- carboranes that lead to the formation of B-I bonds. As for m-carborane, most of the 2a-NPA values of B-H vertexes are positive, and their functionalization is more challenging. The synthesis and full characterization of dibranched 9,10-R2-1,7-closo-carborane (R = CH2CHCH2, HO(CH2)3, Cl(CH2)3, TsO(CH2)3, C6H5COO(CH2)3, C6H5COO(CH2)3, N3(CH2)3, CH3CHCH, and C6H5C2N3(CH2)3) compounds as well as the tetrabranched 9,10-R2-1,7-R2-closo-C2B10H8 (R = CH2CHCH2, HO(CH2)3) are presented. The X-ray diffraction of 9,10-(HO(CH2)3)2-1,7-closo-C2B10H10 and 9,10-(CH3CHCH)2-1,7-closo-C2B10H10, as well as their Hirshfeld surface analysis and decomposed fingerprint plots, are described. These new reported tetrabranched m-carborane derivatives provide a sort of novel core for the synthesis of 3D radially grown periphery-decorated macromolecules that are different to the 2D radially grown core of the tetrabranched o-carborane framework.

Absolute Stereochemistry of (-)-Wieland-Miescher Ketone as Established by the X-ray Crystallographic and CD Exciton Chirality Methods

1992 ◽  
Vol 57 (7) ◽  
pp. 1459-1465 ◽  
Author(s):  
Nobuyuki Harada ◽  
Tatsuo Sugioka ◽  
Hisashi Uda ◽  
Takeo Kuriki
Keyword(s):  
Structure Analysis ◽  
Absolute Configuration ◽  
X Ray ◽  
The Absolute ◽  
Absolute Stereochemistry

The 8aR absolute stereochemistry of Wieland-Miescher ketone (-)-I was established by the X-ray structure analysis of its bis(4-bromobenzoate) derivatives (1R,6R,8aR)-(+)-IV and (1R,6S,8aR)-(-)-V. The absolute configuration of (-)-I was corroborated further by the application of the CD exciton chirality method to bis(4-bromobenzoates) (+)-IV and (-)-V.

scholarly journals Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner
Keyword(s):  
Crystal Structure ◽  
Silica Gel ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
Preparative Scale ◽  
X Ray ◽  
The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

scholarly journals NMR, X-Ray and MS Investigations of Ethyl 2-Aroyl-and Ethyl 2-Arylcarbamoyl-4,5- dimethyl-1,2,3,6-tetrahydropyridazine-1- carboxylates: Flexible Multidentate Ligands

1999 ◽  
Vol 23 (3) ◽  
pp. 186-187
Author(s):  
Erkki Kolehmainen ◽  
Katri Laihia ◽  
Maija Nissinen ◽  
Kalevi Pihlaja ◽  
Alexander Perjéssy ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Multidentate Ligands ◽  
X Ray ◽  
C Nmr

The 1H and 13C NMR spectral assignments of ethyl 2-aroyl-4,5-dimethyl-1,2,3,6-tetrahydropyridazine-1-carboxylates (1a-1h) and ethyl 2-arylcarbamoyl-4,5-dimethyl-1,2,3,6-tetrahydropyridazine-1-carboxylates (2a-2k) are given based on DQF COSY, 1H,13C HMQC and 1H,13C HMBC-measurements; the dynamics of the tetrahydropyridazine ring has been studied by 1H, 1H EXSY-technique and the structure of one congener (4′-methylphenyl-derivative, 2a) has been confirmed by X-ray structure analysis.

Second-Generation Inhibitors for the Metalloprotease Neprilysin Based on Bicyclic Heteroaromatic Scaffolds: Synthesis, Biological Activity, and X-Ray Crystal-Structure Analysis

2005 ◽  
Vol 88 (4) ◽  
pp. 731-750 ◽  
Author(s):  
Stefan Sahli ◽  
Brian Frank ◽  
W. Bernd Schweizer ◽  
François Diederich ◽  
Denise Blum-Kaelin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biological Activity ◽  
Structure Analysis ◽  
Second Generation ◽  
Crystal Structure Analysis ◽  
X Ray

scholarly journals A Versatile Approach to Access Trimetallic Complexes Based on Trisphosphinite Ligands

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 593
Author(s):  
Juan Miranda-Pizarro ◽  
Macarena G. Alférez ◽  
M. Dolores Fernández-Martínez ◽  
Eleuterio Álvarez ◽  
Celia Maya ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Late Transition Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Full Characterization ◽  
Metal Precursors ◽  
Straightforward Method ◽  
One Step ◽  
Late Transition

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.

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