Barriers to rotation around the amide bond and the central carbon-carbon bond in tetrabenzyloxamide and its monothio and dithio analogs

1972 ◽  
Vol 76 (5) ◽  
pp. 642-647 ◽  
Author(s):  
Robert E. Carter ◽  
Jan Sandstrom
Keyword(s):  
Amide Bond ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Central Carbon

The reaction of Sodium Acetylide with Benzil and related compounds

1956 ◽  
Vol 9 (3) ◽  
pp. 391 ◽  
Author(s):  
J Cymerman-Craig ◽  
M Moyle ◽  
P Rowe-Smith ◽  
PC Wailes
Keyword(s):  
Liquid Ammonia ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Central Carbon ◽  
Related Compounds

Attempted condensation of benzil and benzoin with sodium acetylide in liquid ammonia caused fission of the central carbon-carbon bond of these substances, giving 3-phenylprop-1-yn-3-ol. Condensation of α-bromodeoxyanisoin with the same reagent gave several non-acetylenic products which have been identified.

The Conformation of Some 1,1,2,2-Tetraacylethanes in the Solid-State: Crystal-Structures of 1,1,2,2-Tetrabenzoylethane, 1,2-Diacetyl-1,2-Dibenzoylethane and 1,1,2,2-Tetraethoxycarbonylethane

1986 ◽  
Vol 39 (11) ◽  
pp. 1811 ◽  
Author(s):  
JR Cannon ◽  
VA Patrick ◽  
AH White
Keyword(s):  
Solid State ◽  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Keto Form ◽  
Carbon Bond ◽  
X Ray ◽  
Carbon Carbon Bond ◽  
Central Carbon ◽  
Least Squares Techniques

The crystal structures of 1,1,2,2-tetrabenzoylethane (3), 1,2-diacetyl- 1,2-dibenzoylethane (4) and 1,1,2,2-tetraethoxycarbonylethane (tetraethyl ethanetetracarboxylate ) (5) have been determined by X-ray diffraction from diffractometer data at 295 K and were refined by least-squares techniques to residuals of 0.050 (1077 'observed' reflections), 0.056 (3020) and 0.041 (480), respectively. Crystals of (3) are triclinic, Pī , Z 1, a 6.145(2), b 9.002(3), c 11.261(3) Ǻ; α 101.91(3), β 91.88(3), γ 105.94(3)°. Crystals of (4) are also triclinic, Pī , Z 2, a 17.119(5), b 7.210(1), c 7.175(2) Ǻ, α 89.59(2), β 72.92(2), γ 87.87(2)°. Crystals of (5) are tetragonal, P42/n, Z 4, a 17.748(6), c 5.515(1)Ǻ. In the solid state each compound exists in the keto form which adopts the antiperiplanar conformation about the central carbon-carbon bond.

Carbon−Carbon Bond Formation by Electrophilic Addition at the Central Carbon of the μ-η3-Allenyl/Propargyl Ligand on the Pd−Pd Bond

2001 ◽  
Vol 123 (14) ◽  
pp. 3223-3228 ◽  
Author(s):  
Sensuke Ogoshi ◽  
Takuma Nishida ◽  
Ken Tsutsumi ◽  
Motohiro Ooi ◽  
Tsutomu Shinagawa ◽  
...  
Keyword(s):  
Bond Formation ◽  
Electrophilic Addition ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Central Carbon

ROTAMERISM DURING DEMETHYLATION OF THE 2,5-DIMETHOXY-2,5-DIMETHYL-3,4-DIPHENYLHEXANES

1954 ◽  
Vol 32 (8) ◽  
pp. 729-743 ◽  
Author(s):  
J. G. Smith ◽  
George F Wright
Keyword(s):  
The Other ◽  
Stable Conformation ◽  
Carbon Bond ◽  
Other Hand ◽  
Carbon Carbon Bond ◽  
Central Carbon

The fission of methanol from the diastereomeric 2,5-dimethoxy-2,5-dimethyl-3,4-diphenylhexanes leads to products which are best explained in terms of restriction about the central carbon-carbon bond. As would be expected from its stable conformation the dd,ll diastereomer easily forms the 2,2,5,5-tetramethyl-3,4-diphenyltetrahydrofuran, but the meso diastereomer forms a tetrahydrofuran with difficulty. On the other hand the meso diastereomer readily undergoes Friedel-Crafts types of condensation leading in different media to either 3,3-dimethyl-1-isopropenyl-2-phenylindane, 3,3-dimethyl-1-isopropyl-2-phenylindene or 5,5,10,10-tetramethyl-4b,5,9b, 10-tetrahydroindeno[2,1-α]-indene. These indenes are the expected products from a consideration of the conformation of the meso-dimethoxydimethyldiphenylhexane which is most free from steric restriction.

scholarly journals Discovery of a previously unknown biosynthetic capacity of naringenin chalcone synthase by heterologous expression of a tomato gene cluster in yeast

2020 ◽  
Vol 6 (44) ◽  
pp. eabd1143
Author(s):  
Deze Kong ◽  
Sijin Li ◽  
Christina D. Smolke
Keyword(s):  
Methyl Ester ◽  
Gene Cluster ◽  
Chalcone Synthase ◽  
Bond Formation ◽  
Acid Amide ◽  
Gene Clusters ◽  
Amide Bond ◽  
Primary Metabolite ◽  
Carbon Bond ◽  
Carbon Carbon Bond

Chalcone synthase (CHS) canonically catalyzes carbon-carbon bond formation through iterative decarboxylative Claisen condensation. Here, we characterize a previously unidentified biosynthetic capability of SlCHS to catalyze nitrogen-carbon bond formation, leading to the production of a hydroxycinnamic acid amide (HCAA) compound. By expressing a putative tomato (Solanum lycopersicum) gene cluster in yeast (Saccharomyces cerevisiae), we elucidate the activity of a pathway consisting of a carboxyl methyltransferase (SlMT2), which methylates the yeast primary metabolite 3-hydroxyanthranilic acid (3-HAA) to form a methyl ester, and a SlCHS, which catalyzes the condensation of 3-HAA methyl ester and p-coumaroyl-coenzyme A (CoA) through formation of an amide bond. We demonstrate that this aminoacylation activity could be a common secondary activity in plant CHSs by validating the activity in vitro with variants from S. lycopersicum and Arabidopsis thaliana. Our work demonstrates yeast as a platform for characterizing putative plant gene clusters with the potential for compound structure and enzymatic activity discovery.

Carbon Dioxide-Mediated C(sp2)–H Arylation of Primary and Secondary Benzylamines

2018 ◽  
Author(s):  
Mohit Kapoor ◽  
Pratibha Chand-Thakuri ◽  
Michael Young
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal ◽  
Bond Activation ◽  
Bond Formation ◽  
Carbon Bond ◽  
Chelate Effect ◽  
Free Amine ◽  
Carbon Carbon Bond ◽  
New Strategy ◽  
Metal Catalyzed

Carbon-carbon bond formation by transition metal-catalyzed C–H activation has become an important strategy to fabricate new bonds in a rapid fashion. Despite the pharmacological importance of <i>ortho</i>-arylbenzylamines, however, effective <i>ortho</i>-C–C bond formation from C–H bond activation of free primary and secondary benzylamines using Pd<sup>II</sup> remains an outstanding challenge. Presented herein is a new strategy for constructing <i>ortho</i>-arylated primary and secondary benzylamines mediated by carbon dioxide (CO<sub>2</sub>). The use of CO<sub>2</sub> is critical to allowing this transformation to proceed under milder conditions than previously reported, and that are necessary to furnish free amine products that can be directly used or elaborated without the need for deprotection. In cases where diarylation is possible, a chelate effect is demonstrated to facilitate selective monoarylation.

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