Hydrogen atom transfers from thiophenols to triarylmethyl radicals. Rates, substituent effects, and tunnel effects

1979 ◽  
Vol 101 (7) ◽  
pp. 1810-1814 ◽  
Author(s):  
Thomas H. Colle ◽  
Edward S. Lewis
Keyword(s):  
Hydrogen Atom ◽  
Substituent Effects ◽  
Hydrogen Atom Transfers ◽  
Tunnel Effects ◽  
Triarylmethyl Radicals

ChemInform Abstract: ISOTOPE EFFECTS IN HYDROGEN ATOM TRANSFERS. V. THE REACTIONS OF OLEFINS WITH MERCAPTANS

1976 ◽  
Vol 7 (27) ◽  
pp. no-no
Author(s):  
E. S. LEWIS ◽  
M. M. BUTLER
Keyword(s):  
Hydrogen Atom ◽  
Isotope Effects ◽  
Hydrogen Atom Transfers

scholarly journals Site-selective remote C(sp3)–H heteroarylation of amides via organic photoredox catalysis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Hui Chen ◽  
Wenjing Fan ◽  
Xiang-Ai Yuan ◽  
Shouyun Yu
Keyword(s):  
Hydrogen Atom ◽  
Room Temperature ◽  
Ph Value ◽  
Metal Free ◽  
Selective Functionalization ◽  
Site Selectivity ◽  
Hydrogen Atom Transfers ◽  
Site Selective ◽  
Neutral Conditions ◽  
Potential Complement

Abstract Radical translocation processes triggered by nitrogen-centered radicals (NCRs), such as 1,5-hydrogen atom transfers (1,5-HAT), demonstrated by the well-established Hofmann-Löffler-Freytag (HLF) reaction, provide an attractive approach for the controllable and selective functionalization of remote inert C(sp3)–H bonds. Here we report an amidyl radical-triggered site-selective remote C(sp3)–H heteroarylation of amides under organic photoredox conditions. This approach provides a mild and highly regioselective reaction affording remote C(sp3)–H heteroarylated amides at room temperature under transition-metal free, weakly basic, and redox-neutral conditions. Non-prefunctionalized heteroarenes, such as purines, thiazolopyridines, benzoxazole, benzothiazoles, benzothiophene, benzofuran, thiazoles and quinoxalines, can be alkylated directly. Sequential and orthogonal C–H functionalization of different heteroarenes by taking advantage pH value or polarity of radicals has also been achieved. DFT calculations explain and can predict the site-selectivity and reactivity of this reaction. This strategy expands the scope of the Minisci reaction and serves as its alternative and potential complement.

Isotope effects in hydrogen atom transfers. VI. Radicals from azo compounds in thiophenol

1976 ◽  
Vol 98 (8) ◽  
pp. 2260-2264 ◽  
Author(s):  
E. S. Lewis ◽  
K. Ogino
Keyword(s):  
Hydrogen Atom ◽  
Isotope Effects ◽  
Azo Compounds ◽  
Hydrogen Atom Transfers

Functional group and substituent effects, both steric and electronic, upon the ultraviolet absorption spectra of some N-alkyl- and N,N-dialkyl-derivatives of some cinnamamides and benzalcyanoacetamides

1969 ◽  
Vol 47 (17) ◽  
pp. 3278-3280 ◽  
Author(s):  
A. D. Delaney ◽  
D. J. Currie ◽  
H. L. Holmes
Keyword(s):  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Functional Group ◽  
Substituent Effects ◽  
Ultraviolet Absorption ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Derivatives Of

Conjugative and steric constants for N-substituted carboxyamide groups have been derived which allow the calculation of the long wavelength absorption maxima of N-alkyl- and N,N-dialkyl-derivatives of cinnamamide and benzalcyanoacetamide. Deviations between calculated and observed values indicate that there may be steric interference between bulky N,N-dialkylcarboxyamide groups and the benzylic hydrogen atom.

Substituent effects on homolytic versus heterolytic photocleavage of (1-naphthylmethyl)trimethylammonium chlorides

1987 ◽  
Vol 65 (7) ◽  
pp. 1599-1607 ◽  
Author(s):  
B. Foster ◽  
B. Gaillard ◽  
N. Mathur ◽  
A. L. Pincock ◽  
J. A. Pincock ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Hydrogen Atom ◽  
Charge Distribution ◽  
Rate Constants ◽  
Bond Cleavage ◽  
Substituent Effects ◽  
Hydrogen Atom Transfer ◽  
Singlet Excited State ◽  
State Rate

Singlet excited state rate constants have been measured for both the heterolytic and homolytic photocleavage of 3- and 4-methoxy and 3- and 4-cyano (1-naphthylmethyl)trimethylammonium chlorides, 6–10. The results are interpreted in terms of the meta effect or changes in charge distribution upon excitation and the competition between bond cleavage, electron transfer, and hydrogen atom transfer in the contact pairs resulting from the two types of cleavage.

Computed High‐Temperature Rate Constants for Hydrogen‐Atom Transfers Involving Light Atoms

1966 ◽  
Vol 45 (1) ◽  
pp. 385-391 ◽  
Author(s):  
S. W. Mayer ◽  
L. Schieler ◽  
Harold S. Johnston
Keyword(s):  
High Temperature ◽  
Hydrogen Atom ◽  
Rate Constants ◽  
Light Atoms ◽  
Hydrogen Atom Transfers ◽  
Temperature Rate
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