A facile and general acid-catalyzed deuteration at methyl groups of N-heteroarylmethanes

2017 ◽  
Vol 15 (12) ◽  
pp. 2507-2511 ◽  
Author(s):  
Min Liu ◽  
Xue Chen ◽  
Tieqiao Chen ◽  
Shuang-Feng Yin

A general acid-catalyzed deuteration at the methyl group of N-heteroarylmethanes was achieved, which could be conducted at a 500 mmol-scale, showing its good potential for use in large-scale synthesis.

1970 ◽  
Vol 48 (2) ◽  
pp. 263-270 ◽  
Author(s):  
J. M. McAndless ◽  
Ross Stewart

Proton magnetic resonance spectroscopy has been used to examine the deuterium exchange of the methyl protons in two lumazine derivatives. The exchange occurs at the C-7 methyl group in 6,7,8-trimethyllumazine (2) and at the C-6 methyl group in 1,7-dihydro-6,7,8-trimethyllumazine (3). The former reaction is subject to both general acid- and general base-catalysis but the latter only to general acid-catalysis. Plausible mechanisms for the reactions of both compounds are advanced, involving in the case of 3, acid-catalyzed addition of water across the C6—N5 double bond.


1985 ◽  
Vol 63 (12) ◽  
pp. 3290-3293 ◽  
Author(s):  
Ross Stewart ◽  
S. J. Gumbley

A number of lumazines and 5-deazalumazines containing a methyl group at C-7 have been prepared, their pKBH+ values determined, and measurements made of the rates at which the hydrogen atoms of their 7-methyl groups undergo isotopic exchange in aqueous sulfuric acid. The presence of an alkyl group at N-8 in the protonated forms of these compounds activates the neighbouring methyl group at C-7; the effect is considerably larger than that previously observed for a methyl group at C-6, which is the other neighbouring position. The comparison of methyl and hydrogen at N-8 can be made only for the acid-catalyzed reaction because the structures of the neutral compounds, which take part in the base-catalyzed reaction, are not analogous.


2019 ◽  
Author(s):  
Yongzheng Ding ◽  
Shuai Fan ◽  
Xiaoxi Chen ◽  
yuzhen gao ◽  
Gang Li

A Pdᴵᴵ-catalyzed, ligand-enabled gamma-C(sp3)–H arylation of free primary aliphatic amines and amino esters without using an exogenous directing group is reported. This reaction is compatible with unhindered free aliphatic amines, and it is also be applicable to the rapid synthesis of biologically and synthetically valuable unnatural α-amino acids. Large scale synthesis is also feasible using this method.<br>


2019 ◽  
Author(s):  
Alyssa Garreau ◽  
Hanyang Zhou ◽  
Michael Young

<div>Methods to catalytically introduce deuterium in synthetically useful yields ortho to a carboxylic acid directing group on arenes typically requires D2 or CD3CO2D, which makes using these approaches cost prohibitive for large scale synthesis (equipment and reagent costs respectively). Herein we present a simplified approach using catalytic RhIII and D2O as deuterium source, and show its application to H/D exchange on various acidic substrates.</div>


2019 ◽  
Author(s):  
Alyssa Garreau ◽  
Hanyang Zhou ◽  
Michael Young

<div>Methods to catalytically introduce deuterium in synthetically useful yields ortho to a carboxylic acid directing group on arenes typically requires D2 or CD3CO2D, which makes using these approaches cost prohibitive for large scale synthesis (equipment and reagent costs respectively). Herein we present a simplified approach using catalytic RhIII and D2O as deuterium source, and show its application to H/D exchange on various acidic substrates.</div>


2015 ◽  
Vol 12 (2) ◽  
pp. 197-201 ◽  
Author(s):  
Liang Xi ◽  
Di Wu ◽  
Hong-You Zhu ◽  
Cong-Hai Zhang ◽  
Yi Jin ◽  
...  

2008 ◽  
Vol 19 (41) ◽  
pp. 415604 ◽  
Author(s):  
Youngil Lee ◽  
Jun-rak Choi ◽  
Kwi Jong Lee ◽  
Nathan E Stott ◽  
Donghoon Kim

Author(s):  
Nirvik Sen ◽  
Sameer Ekhande ◽  
K.K. Singh ◽  
S. Mukhopadhyay ◽  
R.S. Sirsam ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 165
Author(s):  
Sandip Madhukar Deshmukh ◽  
Mohaseen S. Tamboli ◽  
Hamid Shaikh ◽  
Santosh B. Babar ◽  
Dipak P. Hiwarale ◽  
...  

In the present work, we have reported a facile and large-scale synthesis of TiO2 nanoparticles (NPs) through urea-assisted thermal decomposition of titanium oxysulphate. We have successfully synthesized TiO2 NPs by using this effective route with different weight ratios of titanium oxysulphate: urea. The structures and properties of TiO2 NPs were confirmed by scanning electron microscope) (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), ultra violet–visible spectroscopy (UV-vis), and photoluminescence (Pl) techniques. XRD demonstrated that TiO2 NPs holds of anatase crystal phase with crystallizing size 14–19 nm even after heating at 600 °C. TGA, SEM, and TEM images reveal urea’s role, which controls the size, morphology, and aggregation of TiO2 NPs during the thermal decomposition. These TiO2 NPs were employed for photodegradation of Methyl Orange (MO) in the presence of ultraviolet (UV) radiation. An interesting find was that the TiO2 NPs exhibited better photocatalytic activity and excellent recycling stability over several photodegradation cycles. Furthermore, the present method has a great perspective to be used as an efficient method for large-scale synthesis of TiO2 NPs.


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