scholarly journals Simultaneous construction of axial and planar chirality by gold/TY-Phos-catalyzed asymmetric hydroarylation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pei-Chao Zhang ◽  
Yin-Lin Li ◽  
Jiafeng He ◽  
Hai-Hong Wu ◽  
Zhiming Li ◽  
...  

AbstractThe simultaneous construction of two different chiralities via a simple operation poses considerable challenge. Herein a cationic gold-catalyzed asymmetric hydroarylation of ortho-alkynylaryl ferrocenes derivatives is developed, which enable the simultaneous construction of axial and planar chirality. The here identified TY-Phos derived gold complex is responsible for the high yield, good diastereoselectivity (>20:1 dr), high enantioselectivities (up to 99% ee) and mild conditions. The catalyst system also shows potential application in the synthesis of chiral biaryl compounds. The cause of high enantioselectivity of this hydroarylation is investigated with density functional theory caculation.

Instruments ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 59
Author(s):  
Joshua Mann ◽  
Gerard Lawler ◽  
James Rosenzweig

Electron rescattering has been well studied and simulated for cases with ponderomotive energies of the quasi-free electrons, derived from laser–gas and laser–surface interactions, lower than 50 eV. However, with advents in longer wavelengths and laser field enhancement metallic surfaces, previous simulations no longer suffice to describe more recent strong field and high yield experiments. We present a brief introduction to and some of the theoretical and empirical background of electron rescattering emissions from a metal. We set upon using the Jellium potential with a shielded atomic surface potential to model the metal. We then explore how the electron energy spectra are obtained in the quantum simulation, which is performed using a custom computationally intensive time-dependent Schrödinger equation solver via the Crank–Nicolson method. Finally, we discuss the results of the simulation and examine the effects of the incident laser’s wavelength, peak electric field strength, and field penetration on electron spectra and yields. Future simulations will investigate a more accurate density functional theory metallic model with a system of several non-interacting electrons. Eventually, we will move to a full time-dependent density functional theory approach.


2013 ◽  
Vol 579-580 ◽  
pp. 148-152
Author(s):  
Miao Sun ◽  
Yong Hu ◽  
Hua Guo

TiO2, as photosensitive materials, has attracted much attention owing to its potential application in the solution of environmental pollution during the past decades. Four doped TiO2systems were constructed and studied by using the first principle based Density Functional Theory .The results indicate that P-doped and N-doped TiO2all have better light absorption in the visible light area than pristine TiO2although the band gap of N-doped system reduced less. However, the band gap of F-doped and Cl-doped TiO2increase a little, which causing the absorption to decrease. We suggest from the results that the P atom and N atom are valuable in the modification of TiO2.


Synlett ◽  
2021 ◽  
Author(s):  
Takuya Kurahashi ◽  
Seijiro Matsubara ◽  
Rei Tomifuji ◽  
Shunpei Murano ◽  
Satoru Teranishi ◽  
...  

AbstractThe enantioselective oxa-Diels–Alder reaction of nonactivated substrates by utilizing FeCl3 and a 1,1′-bi-2-naphthol (BINOL) derived chiral phosphoric acid as a multiple activation catalyst is reported. Various oxygen-containing six-membered heterocycles were obtained in high yields and in an enantioselective manner. Density functional theory (DFT) calculations elucidate that both Lewis acidic and Brønsted acidic moieties in the catalyst system synergistically activate two lone pairs of an aldehyde to facilitate enantioselective addition reaction of dienes.


2020 ◽  
Vol 22 (20) ◽  
pp. 11572-11577 ◽  
Author(s):  
Piero Ferrari ◽  
Gao-Lei Hou ◽  
Olga V. Lushchikova ◽  
Florent Calvo ◽  
Joost M. Bakker ◽  
...  

Far-infrared multiple photon dissociation spectroscopy is used in combination with density functional theory calculations to determine the structures of isolated Aun+ (n ≤ 9) clusters.


2016 ◽  
Vol 18 (31) ◽  
pp. 21315-21321 ◽  
Author(s):  
Sherif Abdulkader Tawfik ◽  
X. Y. Cui ◽  
S. P. Ringer ◽  
C. Stampfl

Based on density-functional theory and non-equilibrium Green's function calculations, we demonstrate that endohedral metallofullerenes (EMFs) are reactive to open-shell gases, and therefore have the potential application as selective open-shell gas sensors.


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