23 Questions 24 Answers 0 Followers
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 901 3 View
Which one is appropriate drying agent that can be used before the distillation of SiCl4?
07 April 2018 644 4 View
In general, reaction of NiCl2.6H2O and dppp yield Ni(dppp)Cl2; whether NiCl2.6H2O can be replaced by anhydrous NiCl2 for the same reaction?
23 February 2016 8,234 2 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 2,446 1 View
Out of Pd(PPh3)4 and PdCl2(dppf), which catalyst will be better for the Negishi coupling, in particularly if the bromo-substrate is sterically hindered.
17 September 2015 3,453 5 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 706 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 3,820 3 View
Which catalyst is better for the Miyaura Borylation reaction out of PdCl2(dppf). CH2Cl2 and PdCl2(dppf).
18 June 2015 4,055 10 View
The molecule which have -NO2 group and -TMS can be reduced easliy? For instance, using neutral condition like SnCl2 in ethanol. Although I am still worrying about -TMS group.
30 April 2015 9,667 5 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 5,264 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 4,170 3 View
Which reagent can be successfully employed for the following conversion?
03 January 2015 4,393 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 8,729 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 5,457 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 7,094 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 7,702 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 4,245 10 View
Cyclopentadienone synthesis from prop-1-ynylbenzene and its Cobalt complex. The similar protocol has been successfully employed for the alkynylsilanes (see attached file)
05 July 2014 6,029 9 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 5,717 7 View
Is there any efficient method for the following conversion?
27 May 2014 9,548 4 View
Two isomers of the aldehydes have the same polarity and could not be purified by column chromatography (by using any cosolvent system); re-crystallization was also not possible, as it is...
01 April 2014 8,557 6 View
In Heck coupling, Pd(OAc)2 is used as catalyst. In addition, if we also add PPh3, what will its effect on the reaction rate be? Will it accelerate or slow down the reaction, or have no effect?
26 March 2014 8,189 14 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 6,561 10 View
