N‐Ethynylation of Anilides Decreases the Double‐Bond Character of Amide Bond while Retaining trans ‐Conformation and Planarity

2019 ◽  
Vol 25 (43) ◽  
pp. 10118-10122 ◽  
Author(s):  
Ryu Yamasaki ◽  
Kento Morita ◽  
Hiromi Iizumi ◽  
Ai Ito ◽  
Kazuo Fukuda ◽  
...  
IUCrData ◽  
2016 ◽  
Vol 1 (8) ◽  
Author(s):  
Błażej Dziuk ◽  
Borys Ośmiałowski ◽  
Krzysztof Ejsmont ◽  
Bartosz Zarychta

Molecules of the title compound, C15H19N3O, are composed of an adamantine unit and a pyrazine ring connected to each other through an amide bond. The H—N—C=O moiety is close to planar [C—N—C—O and C—N—C—C torsion angles of 4.7 (2) and −173.8 (1)°, respectively]. The N3—C5 bond has partial double-bond character [1.370 (1) Å]. The geometries of the pyrazine ring and the adamantane substituent are normal and in good agreement with closely related structures. In the crystal, molecules are connected by N—H...O hydrogen bonds, forming zigzag chains in the [001] direction and are arranged in a herringbone fashion.


2015 ◽  
Vol 71 (12) ◽  
pp. o1086-o1087
Author(s):  
Ioannis Tiritiris ◽  
Willi Kantlehner

In the crystal structure of the title salt, C24H38N42+·2C24H20B−, the C—N bond lengths in the central CN3unit of the guanidinium ion are 1.3364 (13), 1.3407 (13) and 1.3539 (13) Å, indicating partial double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charge is delocalized in the CN3plane. The bonds between the N atoms and the terminal methyl groups of the guanidinium moiety and the four C—N bonds to the central N atom of the (benzyldimethylazaniumyl)propyl group have single-bond character. In the crystal, C—H...π interactions between the guanidinium H atoms and the phenyl C atoms of the tetraphenylborate ions are present, leading to the formation of a two-dimensional supramolecular pattern parallel to theacplane.


2012 ◽  
Vol 68 (6) ◽  
pp. o1812-o1812 ◽  
Author(s):  
Ioannis Tiritiris ◽  
Willi Kantlehner

The reaction of 3,3,3-tris(dimethylamino)-1-phenylprop-1-yne with bromine in pentane yields the title compound, C13H17N2 +·Br−. The acetylenic bond distance [1.197 (2) Å] is consistent with a C[triple-bond]C triple bond. The amidinium C=N bonds [1.325 (2) and 1.330 (2) Å] have double-bond character and the positive charge is delocalized between the two dimethylamino groups.


1955 ◽  
Vol 33 (1) ◽  
pp. 128-133 ◽  
Author(s):  
R. U. Lemieux ◽  
G. Huber

3,4,6-Tri-O-acetyl-β-D-glucopyranosyl chloride was found to undergo solvolysis in acetic acid to form 1,3,4,6-tetra-O-acetyl-α-D-glucopyranose as the main reaction product. The much less reactive anomeric α-chloride also appeared to undergo solvolysis with extensive inversion of the anomeric center. It is submitted that the tendencies for inversion obtained in these ionic reactions are due to the conformations imposed on the intermediate ions through distribution of the positive charge to the ring oxygen and the consequent introduction of double-bond character to the carbon-1 to ring-oxygen bond.


IUCrData ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Ioannis Tiritiris ◽  
Willi Kantlehner

The asymmetric unit of the title salt, 2C5H12N3O+·SO42−, comprises two cations and one sulfate ion. In both cations, the C, N and O atoms of the morpholine rings are disordered over two sets of sites, with refined occupancies of 0.849 (3):0.151 (3) for cation I and 0.684 (4):0.316 (4) for cation II. The C—N bond lengths in both central C3N units of the carboxamidinium ions range between 1.253 (12) and 1.362 (5) Å, indicating a degree of double-bond character. The central C atoms are bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charges are delocalized in both CN3planes. The crystal structure is stabilized by a three-dimensional network of N—H...O hydrogen bonds between the cations and the sulfate ion. Scheme tiny font, charges and delocalized bonds almost invisible


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