scholarly journals Dehydrogenative coupling of 4-substituted pyridines mediated by a zirconium(ii) synthon: reaction pathways and dead ends

2018 ◽  
Vol 9 (23) ◽  
pp. 5223-5232 ◽  
Author(s):  
Lukas S. Merz ◽  
Hubert Wadepohl ◽  
Eric Clot ◽  
Lutz H. Gade
Keyword(s):  
Reaction Pathways ◽  
Pyridine Derivatives ◽  
Dehydrogenative Coupling ◽  
Substituted Pyridines ◽  
Reductive Homocoupling

The mechanism of the reductive homocoupling of pyridine derivatives mediated by the ZrII synthon [(PNP)Zr(η6-toluene)Cl] (1) has been investigated.

Dehydrogenative Coupling of 4-Substituted Pyridines Catalyzed by Diruthenium Complexes

2007 ◽  
Vol 129 (36) ◽  
pp. 11006-11007 ◽  
Author(s):  
Takashi Kawashima ◽  
Toshiro Takao ◽  
Hiroharu Suzuki
Keyword(s):  
Dehydrogenative Coupling ◽  
Substituted Pyridines

The nature of the coordination bond in metal complexes of substituted pyridine derivatives. III. 4-Methylpyridine complexes of some divalent transition metal ions

1968 ◽  
Vol 46 (20) ◽  
pp. 3137-3141 ◽  
Author(s):  
D. G. Brewer ◽  
P. T. T. Wong ◽  
M. C. Sears
Keyword(s):  
Infrared Spectroscopy ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Ions ◽  
Coordination Bond ◽  
Pyridine Derivatives ◽  
Normal Coordinate ◽  
Substituted Pyridines ◽  
Solid Complexes ◽  
Nitrogen Bond

Previous papers in this series investigated the nature of the coordination bond in copper(II) and zinc(II) complexes of 4-substituted pyridines by infrared spectroscopy. In this paper, the investigation has been extended to complexes of 4-methylpyridine with cobalt(II), manganese(II), and nickel(II). The geometry of the solid complexes is assigned, and the force constants associated with the metal–nitrogen bond were calculated from a normal coordinate analysis. The validity of the previously introduced Rπ parameter in these systems is discussed.

Dehydrogenative Coupling of 4-Substituted Pyridines Catalyzed by a Trinuclear Complex of Ruthenium and Cobalt

2016 ◽  
Vol 35 (14) ◽  
pp. 2348-2360 ◽  
Author(s):  
Masahiro Nagaoka ◽  
Takashi Kawashima ◽  
Hiroharu Suzuki ◽  
Toshiro Takao
Keyword(s):  
Trinuclear Complex ◽  
Dehydrogenative Coupling ◽  
Substituted Pyridines

scholarly journals Metal-free cross-dehydrogenative coupling approach for C-H bond functionalization of 2-phenyl pyridine derivatives in water

2018 ◽  
Vol 29 (3) ◽  
pp. e21423
Author(s):  
Gogu Venkata Surendra Babu ◽  
Parvathaneni Sai Prathima ◽  
Pullaiah C. Perumgani ◽  
Balasubramanian Sridhar ◽  
Tumula Venkateshwar Rao ◽  
...  
Keyword(s):  
Pyridine Derivatives ◽  
Bond Functionalization ◽  
Metal Free ◽  
Dehydrogenative Coupling ◽  
Coupling Approach

ChemInform Abstract: Dehydrogenative Coupling of 4-Substituted Pyridines Catalyzed by Diruthenium Complexes.

ChemInform ◽  
2008 ◽  
Vol 39 (4) ◽  
Author(s):  
Takashi Kawashima ◽  
Toshiro Takao ◽  
Hiroharu Suzuki
Keyword(s):  
Dehydrogenative Coupling ◽  
Substituted Pyridines

Nucleophilic square-planar substitutions. II. Substitutions of the bromodiethylenetriamineplatinum(II) complex by pyridine derivatives

1968 ◽  
Vol 21 (12) ◽  
pp. 2873 ◽  
Author(s):  
SC Chan ◽  
FT Wong
Keyword(s):  
Activation Energy ◽  
Rate Constants ◽  
Steric Effects ◽  
Pyridine Derivatives ◽  
Arrhenius Parameters ◽  
Associative Mechanism ◽  
Square Planar ◽  
Inductive Effects ◽  
Two Factors ◽  
Substituted Pyridines

The second-order rate constants for the replacement of coordinated bromide from bromodiethylenetriamineplatinum(11) bromide by a series of pyridine derivatives have been determined over a range of temperatures and the Arrhenius parameters calculated. With the exception of the cyano derivative, replacements of 2-substituted pyridines are considerably slower than those by the corresponding 3- or 4-substituted nucleophiles. This is explicable on the basis of the associative mechanism by invoking steric effects of the substituents. The activation energies for the reaction depend mainly on a combination of two factors, steric and inductive, with the former predominating. These decrease as the position of a given substituent in the nucleophile changes in the order 2, 3, and 4. The inductive effects of the various substituents may be demonstrated with the 4-substituted pyridines, which are sterically similar to the unsubstituted pyridine itself. The methyl substitutent has a small effect, while the cyano and chloro substituents lead to significant increases in activation energy.

Nature of the coordination bond in metal complexes of substituted pyridine derivatives. I. The substituent effect on the coordination bond

1968 ◽  
Vol 46 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Patrick T. T. Wong ◽  
D. G. Brewer
Keyword(s):  
Free Energy ◽  
Bond Strength ◽  
Metal Complexes ◽  
Infrared Spectra ◽  
Substituent Effect ◽  
Coordination Bond ◽  
Spectroscopic Methods ◽  
Pyridine Derivatives ◽  
Coordination Center ◽  
Substituted Pyridines

The nature of the coordination bond in some metal complexes of 4-substituted pyridines has been investigated by thermodynamic and infrared spectroscopic methods. The effects of the substituents upon the coordination bond strength in the copper(II) complexes of these ligands have been found by direct measurement of the heats of coordination. These effects have been further described by the substituent effect upon the change in free energy of the coordination center in the ligands. A new parameter, Rπ, measuring the relative π bonding in the complexes of 4-substituted pyridines has been introduced. For this purpose a series of complexes of the types [M(4—R—C5H4N)2Cl2] and [(4—R—C5H4N)•HCl] (R = CH3, CH2OH, H, COCH3, CONH2, COOCH3, CN; M = Cu(II), Zn(II)) has been isolated, and the infrared spectra of these complexes and the free ligands have been examined.

Cobalt-catalyzed acceptorless dehydrogenative coupling of aminoalcohols with alcohols: direct access to pyrrole, pyridine and pyrazine derivatives

2018 ◽  
Vol 54 (1) ◽  
pp. 90-93 ◽  
Author(s):  
Siba P. Midya ◽  
Vinod G. Landge ◽  
Manoj K. Sahoo ◽  
Jagannath Rana ◽  
Ekambaram Balaraman
Keyword(s):  
Amino Alcohols ◽  
Direct Access ◽  
Secondary Alcohols ◽  
Pyridine Derivatives ◽  
Dehydrogenative Coupling

A molecularly defined SNS-cobalt(ii) catalyst for the acceptorless dehydrogenative coupling (ADC) of unprotected amino alcohols with secondary alcohols leading to pyrrole and pyridine derivatives is reported.

A simple, tandem approach to the construction of pyridine derivatives under metal-free conditions: a one-step synthesis of the monoterpene natural product, (−)-actinidine

2019 ◽  
Vol 55 (22) ◽  
pp. 3270-3273 ◽  
Author(s):  
Dilipkumar Uredi ◽  
Damoder Reddy Motati ◽  
E. Blake Watkins
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Pyridine Derivatives ◽  
Metal Free ◽  
Substituted Pyridines ◽  
One Step

(−)-Actinidine, along with various diversely substituted pyridines were synthesized from simple starting materials, including natural products, using a mild and metal-free method.

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