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Questions related from Dhirendra Kumar
When HOCl is added to propene, the product is 1-chloro 2-propanol. However, when the same HOCl adds to allyl alcohol, the expected product is 3-chloropropan-1, 2-diol. But actually,...
21 October 2019 823 3 View
I did the halogen dance reaction of 2-bromo-5-TIPS thiophene using LDA/methanol to get 3-bromo-5-TIPS thiophene. But there reaction was not completed 100% and there is ~5-10% of starting material...
23 December 2015 2,408 1 View
Generally it was found that the use of additives in redox mediator [iodide/triiodide] cause not only improved performance but also increase device stability. In particular, I want to know the...
03 July 2015 637 3 View
In the Miyaura-borylation reaction, the excess (BPin)2 was eluted along with product (aryl-boronic ester) due to close polarity [confirmed from 1H-NMR]. As (BPin)2 is invisible in the UV-light, it...
22 June 2015 3,740 3 View
Which catalyst is better for the Miyaura Borylation reaction out of PdCl2(dppf). CH2Cl2 and PdCl2(dppf).
18 June 2015 4,016 10 View
The trimethylsilyl-group can tolerate the nitrating mixture such as HNO3+AcOH. The similar compound can be easily nitrated but I am worrying about TMS present on it.
24 March 2015 5,214 5 View
For instance, 4,4,5,5-tetramethyl-2-(thiophen-3-yl)-1,3,2-dioxaborolane can be treated safely with BuLi; or the presence of -boronic ester would give trouble. Is any other reagent such as LDA can...
04 February 2015 4,111 3 View
Which reagent can be successfully employed for the following conversion?
03 January 2015 4,346 6 View
The milder method for the exclusive oxidation of the aromatic aldehyde having electron rich skeleton. I am worried about oxidation of aromatic part also under harsh conditions.
28 October 2014 8,675 20 View
I have seen a paper (attached) and also observed myself that phenazine/dihydrophenazine-based compounds either didn't show or have very-2 broader peaks in the proton NMR when recorded in the...
15 October 2014 5,397 2 View
The synthesis of 3-thiophenyl magnesium bromide is possible or not by the reaction of Mg and 3-bromothiophene simply similar to that for 2-bromothiophene. Is the use of t-BuLi necessary to...
29 August 2014 7,050 8 View
Which reagent out of n-BuLi, t-BuLi and LDA will give 100% clean lithiated product 3-thiophenyl lithium, when reacted with 3-bromothiophene.
20 August 2014 7,515 8 View
The proton NMR peak of water changes with respect to the solvent; e.g. 1.56 in CDCl3, 3.33 in DMSO-d6, 0.40 in benzene-d6 etc.
14 July 2014 4,168 10 View
The reaction of aryl phosphonates with carbonyls in the presence of t-BuOK in THF yields exclusively (E-)olefins. Can the use of LiCl further improve the (E)-isomer up to 100%?
19 June 2014 5,647 7 View
Is there any efficient method for the following conversion?
27 May 2014 9,499 4 View
I did N-alkylation of a substrate by using K2CO3, 2-ethylhexyl bromide in DMF. After purification by column chromatography I got a liquid product. The problem is the presence of 2-ethylhexyl...
14 March 2014 6,500 10 View