Photoinduced Electron Transfer-Initiated Enantioselective Cyclization of N-Benzoyl-α-dehydroarylalanine tert-Butyl Esters in the Presence of Chiral Amine

Heterocycles ◽  
2007 ◽  
Vol 74 (1) ◽  
pp. 149 ◽  
Author(s):  
Tadamitsu Sakurai ◽  
Haruo Watanabe ◽  
Kei Maekawa ◽  
Tetsutaro Igarashi
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Chiral Amine ◽  
Tert Butyl ◽  
Butyl Esters

scholarly journals Photoinduced electron transfer in 2- tert -butyl-3-(anthracen-9-yl)-2,3-diazabicyclo[2.2.2]octane

2006 ◽  
Author(s):  
Guadalupe Valverde-Aguilar ◽  
Jorge Garcia-Macedo ◽  
Xianghuai Wang ◽  
Jeffrey I. Zink ◽  
Stephen F. Nelsen
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Tert Butyl

Products from photochemical reactions and electrochemical oxidation of methylenecyclopropane

1997 ◽  
Vol 75 (12) ◽  
pp. 1795-1809 ◽  
Author(s):  
H.J.P. de Lijser ◽  
T. Stanley Cameron ◽  
Donald R. Arnold
Keyword(s):  
Electron Transfer ◽  
Ionization Potential ◽  
Radical Cation ◽  
Photoinduced Electron Transfer ◽  
Nucleophilic Addition ◽  
Major Product ◽  
Oxidation Potential ◽  
Photochemical Reactions ◽  
Tert Butyl ◽  
Adiabatic Ionization Potential

The reactivity of methylenecyclopropane (MCP, 1) and its radical cation (1+•) have been studied in the presence and absence of a nucleophile (methanol). Photochemical reactions of 1 in the presence of an electron-acceptor (1,4-dicyanobenzene, 6) and a codonor (biphenyl, 7) in acetonitrile (with and without methanol present) or chloroform lead to cycloadditions (ortho, meta, and para; products 12–17) rather than products from photoinduced electron transfer (PET). Based on the measured (cyclic voltammetry, CV) oxidation potential, using the Weller equation, electron transfer (ET) was predicted to occur. It was shown that the measured oxidation potential of 1 represents the adiabatic ionization potential. For PET processes the value for the vertical ionization potential must be used. Electrochemical (EC) generation of 1+• without a nucleophile present results in the formation of one major product: tert-butyl acetamide (25). A series of rearrangements leading to the tert-butyl cation is proposed. Addition of a nucleophile (methanol) to the mixture leads to the formation of 3-methoxy-2-(methoxymethyl)-1-propene (26). This product may arise from trapping of the initially formed ring-opened (trimethylenemethane) radical cation (1a+•), which undergoes a second oxidation and nucleophilic addition (ECE). Keywords: methylenecyclopropane, radical cation, photochemistry, electrochemistry, photocycloaddition.

Alkyl radicals from t-butyl esters through photoinduced electron transfer

1994 ◽  
Vol 35 (49) ◽  
pp. 9275-9278 ◽  
Author(s):  
Elisa Fasani ◽  
Diego Peverali ◽  
Angelo Albini
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Alkyl Radicals ◽  
Butyl Esters

Photoinduced Electron Transfer in 2-tert-Butyl-3-(Anthracen-9-yl)-2,3-Diazabicyclo[2.2.2]octane

2006 ◽  
Vol 128 (18) ◽  
pp. 6180-6185 ◽  
Author(s):  
Guadalupe Valverde-Aguilar ◽  
Xianghuai Wang ◽  
Stephen F. Nelsen ◽  
Jeffrey I. Zink
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Tert Butyl

Computationally Assisted Design of High Signal-to-Noise Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes

2020 ◽  
Author(s):  
Rishikesh Kulkarni ◽  
Anneliese Gest ◽  
Chun Kei Lam ◽  
Benjamin Raliski ◽  
Feroz James ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dft Calculations ◽  
Photoinduced Electron Transfer ◽  
Density Functional ◽  
Embryonic Stem ◽  
High Sensitivity ◽  
Md Simulations ◽  
High Signal ◽  
Signal To Noise ◽  
Green Fluorescent

<p>High signal-to-noise optical voltage indicators will enable simultaneous interrogation of membrane potential in large ensembles of neurons. However, design principles for voltage sensors with high sensitivity and brightness remain elusive, limiting the applicability of voltage imaging. In this paper, we use molecular dynamics (MD) simulations and density functional theory (DFT) calculations to guide the design of a bright and sensitive green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD simulations predict an 11% increase in sensitivity due to membrane orientation, while DFT calculations predict an increase in fluorescence quantum yield, but a decrease in sensitivity due to a decrease in rate of PeT. We confirm these predictions by synthesizing a new VF dye and demonstrating that it displays the expected improvements by doubling the brightness and retaining similar sensitivity to prior VF dyes. Combining theoretical predictions and experimental validation has resulted in the synthesis of the highest signal-to-noise green VF dye to date. We use this new voltage indicator to monitor the electrophysiological maturation of human embryonic stem cell-derived medium spiny neurons. </p>

scholarly journals PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation

2021 ◽  
pp. 174751982098753
Author(s):  
Xiaofang Wu ◽  
Lei Zhou ◽  
Fangshao Li ◽  
Jing Xiao
Keyword(s):  
Acid Chloride ◽  
Bioactive Molecules ◽  
Mechanistic Studies ◽  
One Pot ◽  
Tert Butyl ◽  
Butyl Esters

A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.

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