scholarly journals Acid-catalyzed tandem reaction for the synthesis of pyridine derivatives via CC/C(sp3)–N bond cleavage of enones and primary amines

RSC Advances ◽  
2017 ◽  
Vol 7 (22) ◽  
pp. 13123-13129 ◽  
Author(s):  
Zhong-Yuan Mao ◽  
Xiao-Yun Liao ◽  
Heng-Shan Wang ◽  
Chun-Gu Wang ◽  
Ke-Bin Huang ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Primary Amines ◽  
Tandem Reaction ◽  
Pyridine Derivatives ◽  
Acid Catalyzed

2,4,6-Trisubstituted pyridines can be generated from an acid-catalyzed tandem reaction via CC/C(sp3)–N bond cleavage of enones and primary amines.

α-Ketophosphonates in the Synthesis of α-iminophosphonates

2020 ◽  
Vol 7 (2) ◽  
pp. 226-238
Author(s):  
Petro P. Ony`sko ◽  
Tetyana I. Chudakova ◽  
Vladimir V. Pirozhenko ◽  
Alexandr B. Rozhenko
Keyword(s):  
Bond Cleavage ◽  
Direct Synthesis ◽  
Equilibrium Mixture ◽  
Primary Amines ◽  
Alkyl Amines ◽  
Protic Solvents ◽  
Metallic Salts ◽  
Direct Preparation ◽  
Stage Synthesis ◽  
Aprotic Dipolar Solvent

The potentialities of condensation of α-ketophosphonates with primary amines for direct synthesis of α-iminophosphonates have been revealed. Diesters of α-ketophosphonic acids react with the primary amines by two competitive pathways: with a formation of α-iminophosphonates or a C-P bond cleavage resulting in a hydrogen phosphonate and an acylated amine. In many cases, the latter undesirable pathway is dominant, especially for more nucleophilic alkyl amines. Using metallic salts of α-ketophosphonates avoids the C-P bond cleavage, allowing direct preparation of α-phosphorylated imines by the reaction with primary amines. This strategy provides an atom economy single-stage synthesis of iminophosphonates – precursors of bio relevant phosphorus analogs of α-amino acids. Methyl sodium iminophosphonates, bearing aryl or heteryl substituents at the imino carbon atom exist in solutions at room temperature as an equilibrium mixture of Z- and E-isomers. A configuration of the C=N bond can be controlled by the solvent: changing the aprotic dipolar solvent DMSO-d6 by water or alcohols leads to the change from a predominant Z-isomer to almost an exclusive E-form. In contrast, diesters of the respective iminophosphonates exist in non-protic solvents predominantly in Econfiguration. The solvent effect on E-Z stereochemistry is demonstrated by DFT calculations.

scholarly journals An Isolable Mononuclear Palladium(I) Amido Complex

2021 ◽  
Author(s):  
jian Liu ◽  
Melissa Bollmeyer ◽  
Yujeong Kim ◽  
Dengmengfei Xiao ◽  
Samantha N. Macmillan ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Bond Cleavage ◽  
Primary Amines ◽  
Dispersion Force ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pauli Repulsion ◽  
Catalyzed Reactions ◽  
Electron Paramagnetic

Mononuclear Pd(I) species are putative intermediates in Pd-catalyzed reactions, but our knowledge about them is limited due to difficulties in accessing them. Herein, we report the isolation of a Pd(I) amido complex, [(BINAP)Pd(NHArTrip )] (BINAP = 2,2′- bis(diphenylphosphino)-1,1′-binaphthalene, ArTrip = 2,6-bis(2’,4’,6’-triisopropylphenyl)phenyl), from the reaction of (BINAP)PdCl2 with LiNHArTrip. This Pd(I) amido species has been characterized by X-ray crystallography, electron paramagnetic resonance, and multi-edge Pd Xray absorption spectroscopy. Theoretical study revealed that, while the 3-electron-2-center π interaction between Pd and N in the Pd(I) complex imposes severe Pauli repulsion in its Pd–N bond, pronounced attractive inter-ligand dispersion force aids its stabilization. In accord with its electronic features, reactions of homolytic Pd–N bond cleavage and deprotonation of primary amines are observed on the Pd(I) amido complex.

Bond cleavage in acid-catalyzed hydrolysis of vinyl phosphates

1972 ◽  
Vol 94 (10) ◽  
pp. 3676-3677 ◽  
Author(s):  
Edward P. Lyznicki ◽  
Thomas T. Tidwell
Keyword(s):  
Bond Cleavage ◽  
Acid Catalyzed ◽  
Hydrolysis Of

scholarly journals Unique cyclolignan’s architecture obtained via acid catalyzed cyclization/intramolecular Friedel-Crafts tandem reaction

ARKIVOC ◽  
2020 ◽  
Vol 2020 (7) ◽  
pp. 46-55
Author(s):  
Krzysztof K. Krawczyk ◽  
Kamil Lisiecki ◽  
Zbigniew Czarnocki
Keyword(s):  
Tandem Reaction ◽  
Acid Catalyzed
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