The Beckman Rearrangement. VIII. The Influence of Alkyl Groups on the Rates of Rearrangement of Acetophenone Oximes1

1959 ◽  
Vol 81 (3) ◽  
pp. 612-618 ◽  
Author(s):  
Patrick J. McNulty ◽  
D. E. Pearson
Keyword(s):  
Alkyl Groups ◽  
Beckman Rearrangement

Electrochemical Vicinal Difluorination of Alkenes: Sustainable, Scalable, and Amenable to Electron-rich Substrates

2019 ◽  
Author(s):  
Sayad Doobary ◽  
Alexi Sedikides ◽  
Henry caldora ◽  
Darren poole ◽  
Alastair Lennox
Keyword(s):  
Bioactive Compounds ◽  
Hypervalent Iodine ◽  
Electrochemical Generation ◽  
Oxidative Decomposition ◽  
Alkyl Groups ◽  
Rich Functionality

Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and F conformation. The oxidative difluorination of alkenes represents an H important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products that are otherwise unattainable. Key to success is the electrochemical generation of a hypervalent iodine mediator (in the presence of nucleophilic fluoride and HFIP) using an ‘ex-cell’ approach, which avoids the oxidative decomposition of the substrate. The more sustainable conditions give good to excellent yields of product in up to decagram scales<br>

Alkyl 1-[2-(oxido anion)-, 3-, 4-, 5-alkyl substituted]phenyl ketyl radicals

1979 ◽  
Vol 44 (6) ◽  
pp. 1731-1741 ◽  
Author(s):  
Andrej Staško ◽  
Ľubomír Malík ◽  
Alexander Tkáč ◽  
Vladimír Adamčík ◽  
Eva Maťašová
Keyword(s):  
Electron Donor ◽  
Unpaired Electron ◽  
Grignard Reagents ◽  
Slight Effect ◽  
Benzene Nucleus ◽  
Alkyl Groups ◽  
Splitting Constant

Reactions of R2,R3-alkyl substituted 2-hydroxybenzenecarboxylic acids 2-HO-C6H2R2-COOH with Grignard reagents R1MgBr in the presence of nickel give stable aryl alkyl ketyl radicals 2-O--R2-, R3-C6H2-CO--R1 where R1 = CH3, C2H5, C2D5, n-C3H7 and R2,R3 = CH3, C2H5, i-C3H7, t-C4H9. The β protons of ketyl group are equivalent (splitting constant 1.25 mT) and non-equivalent (splitting constants within 0.5 to 1.5 mT) for R1 = methyl and other alkyl groups, respectively. Interaction of the γ protons with the unpaired electron was only observed in the case of R1 = n-propyl (splitting constants about 0.07 mT). The substituents R1 have but slight effect on values of splitting constants of the protons in R2,R3 and vice versa. Also splitting constants of the benzene nucleus (a4H = 0.55 mT, a6H = 0.44 mT) are only slightly affected by the substituents R1,R2,R3, which indicates dominant electron-donor effect of the oxido-anion group eliminating the relatively smaller contributions of the alkyl substituents.

Kinetics of the Imidazolium Ring-Opening of mRNA 5'-cap Analogs in Aqueous Alkali

2006 ◽  
Vol 71 (4) ◽  
pp. 567-578 ◽  
Author(s):  
Alicja Stachelska ◽  
Zbigniew J. Wieczorek ◽  
Janusz Stępiński ◽  
Marzena Jankowska-Anyszka ◽  
Harri Lönnberg ◽  
...  
Keyword(s):  
Electrostatic Interaction ◽  
Ring Opening ◽  
Nucleophilic Attack ◽  
Amino Groups ◽  
Hydroxide Ion ◽  
Methyl Group ◽  
Structural Modifications ◽  
Alkyl Groups ◽  
Imidazolium Ring ◽  
Kinetics Of

Second-order rate constants for the hydroxide-ion-catalyzed imidazolium ring-opening of several mono- and dinucleosidic analogs of mRNA 5'-cap have been determined. Intramolecular stacking of the two nucleobases in the dinucleosidic analogs, m7GpppN (m7G = 7-methylguanosine, N = 5'-linked nucleoside), and electrostatic interaction between the N-alkylated imidazolium ring and phosphate moiety have been shown to shield the m7G moiety against the nucleophilic attack of hydroxide ion. In addition, the effect of methylation of the nucleobase amino groups and replacement of the 7-methyl group with other alkyl groups have been studied. The influence of all the structural modifications studied turned out to be modest, the cleavage rates of the most and least reactive analogs (with the exception of non-phosphorylated nucleosides) differing only by a factor of 5.

Ti-Oxo Clusters with Peripheral Alkyl Groups as Cathode Interlayers for Efficient Organic Solar Cells

2021 ◽  
Author(s):  
Xing Chen ◽  
Yingzi Han ◽  
Jie Fang ◽  
Zhou Zhang ◽  
Yuefeng Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Alkyl Groups

Chiral Alkyl Groups at Position 3(1′) of Pyropheophorbide-a Specify Uptake and Retention by Tumor Cells and Are Essential for Effective Photodynamic Therapy

2021 ◽  
Vol 64 (8) ◽  
pp. 4787-4809
Author(s):  
Ravindra R. Cheruku ◽  
Erin C. Tracy ◽  
Walter Tabaczynski ◽  
Joseph R. Missert ◽  
Heinz Baumann ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Tumor Cells ◽  
Alkyl Groups ◽  
Pyropheophorbide A

scholarly journals The Mechanism of Introduction of Alkyl Groups at C-24 of Sterols

1967 ◽  
Vol 242 (24) ◽  
pp. 5796-5801 ◽  
Author(s):  
M. Castle ◽  
G.A. Blondin ◽  
William R. Nes
Keyword(s):  
Alkyl Groups

scholarly journals The Mechanism of Introduction of Alkyl Groups at C-24 of Sterols

1967 ◽  
Vol 242 (24) ◽  
pp. 5802-5806
Author(s):  
Paul T. Russell ◽  
Robert T. van Aller ◽  
William R. Nes
Keyword(s):  
Alkyl Groups
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