π Activation of Alkynes in Homogeneous and Heterogeneous Gold Catalysis.

J Phys Chem A

Dipartimento di Chimica, Biologia e Biotecnologie, Universitá di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy.

Published: July 2016


Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

The activation of alkynes toward nucleophilic attack upon coordination to gold-based catalysts (neutral and positively charged gold clusters and gold complexes commonly used in homogeneous catalysis) is investigated to elucidate the role of the σ donation and π back-donation components of the Au-C bond (where we consider ethyne as prototype substrate). Charge displacement (CD) analysis is used to obtain a well-defined measure of σ donation and π back-donation and to find out how the corresponding charge flows affect the electron density at the electrophilic carbon undergoing the nucleophilic attack. This information is used to rationalize the activity of a series of catalysts in the nucleophilic attack step of a model hydroamination reaction. For the first time, the components of the Dewar-Chatt-Duncanson model, donation and back-donation, are put in quantitative correlation with the kinetic parameters of a chemical reaction.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jpca.6b01037DOI Listing

Publication Analysis

Top Keywords

nucleophilic attack
12
donation back-donation
12
activation alkynes
8
alkynes homogeneous
4
homogeneous heterogeneous
4
heterogeneous gold
4
gold catalysis
4
catalysis activation
4
alkynes nucleophilic
4
attack coordination
4

Similar Publications

In this study, we seek to deepen the understanding of the Fe effect in Ni-oxyhydroxide-mediated oxygen evolution reaction (OER) electrocatalysis in alkaline conditions, where extremely small amounts of Fe can have a dramatic impact on catalytic performance. For this purpose, Density Functional Theory (DFT) electronic structure calculations with implicit solvation description is employed in a constant pH/potential simulation framework. Nanoparticle models are considered for the nickel-based oxyhydroxide material with different degrees of Fe incorporation, and the pH/U-dependent interface structure is studied.

View Article and Find Full Text PDF

-Adenosyl-l-methionine (SAM) is well-known as a methyl donor for methyltransferases but also functions as a 3-amino-3-carboxypropyl (3-ACP) donor for 3-ACP transferases. NAT is a 3-ACP transferase which accepts β-lactam antibiotic nocardicin G () and SAM to produce isonocardicin C. Due to the lack of structural information about this enzyme, its reaction mechanism has not been fully identified.

View Article and Find Full Text PDF

Azolo[1,5-]pyrimidines (APs) are widely recognized as challenging scaffolds for diverse applications in both medicinal chemistry and materials science. Owing to their high potential, active research is focused on developing new derivatives through the derivatization and functionalization of their molecular structure. Herein, we report an unusual transformation in the AP series initiated by a hydroperoxide anion.

View Article and Find Full Text PDF

The synthesis of α-ketoamides through oxidative ring opening of 1-acetylindoline-3-one under electrochemical conditions is reported. In an undivided cell, the reaction proceeds via the formation of an iminium ion intermediate, nucleophilic attack by a hydroxide ion, and subsequent ring opening through pre-existing C-N bond cleavage. The reaction in the presence of HO confirms that the amidic oxygen originated from the moisture present in the medium.

View Article and Find Full Text PDF

This work investigated the ring-opening reaction mechanism between F and oxirane by combining electronic structure calculations with chemical dynamics simulations. Electronic structure calculations revealed two primary reaction pathways: nucleophilic substitution (S2) and elimination (E2). The S2 pathway was further classified into oxygen-side attack (ret-S2) and backside attack (inv-S2) based on the nucleophilic approach direction.

View Article and Find Full Text PDF