Usama Karama

Prof. Usama Karama


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 September 2015 in Molecules
Verified
Journal Article
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ANArumugam Natarajan
Arumugam Natarajan
AIAlmansour Abdulrahman I
Almansour Abdulrahman I
SRSuresh Kumar Raju
Suresh Kumar Raju
J. Carlos MenéndezJ. Carlos Menéndez
J. Carlos Menéndez
MSMujeeb Sultan
Mujeeb Sultan
HFHoong-Kun Fun
Hoong-Kun Fun
A series of hitherto unreported anthracene-embedded dispirooxindoles has been synthesized via a one-pot three-component 1,3-dipolar cycloaddition reaction of an azomethine ylide, generated in situ from the reaction of isatin and sarcosine to 10-benzylideneanthracen-9(10H)-one as a dipolarophile in 1-butyl-3-methylimidazolium bromide([bmim]Br), an ionic liquid. This reaction proceeded regio- and diastereoselectively, in good to excellent yields.

4 May 2010 in Molecules
Verified
Journal Article
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UKUsama Karama
Usama Karama
ZAZeid ALOthman
Zeid ALOthman
AAAbdullah Al-Majid
Abdullah Al-Majid
AAAbdulrahman Almansour
Abdulrahman Almansour
Treatment ofN-bromosuccinimide (NBS) with (carboethoxymethylene) triphenylphosphorane (1) in CH2Cl2 followed by the addition of an alcohol in the presence of manganese dioxide under ultrasonic irradiation constitutes a stereoselective one-pot procedure for the preparation of Z-configured α–bromo-α,β-unsaturated esters in good to excellent yield.

5 January 2016 in Molecules
Verified
Journal Article
Open access
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UKUsama Karama
Usama Karama
MSMujeeb Sultan
Mujeeb Sultan
AIAlmansour Abdulrahman I
Almansour Abdulrahman I
KEKamal Eldin El-Taher
Kamal Eldin El-Taher
The synthesis of the tetracyclic compounds 1-(4,5-dichloro-9,10-dihydro-9,10-ethanoanthracen-11-yl)-N-methylmethanamine (5) and 1-(1,8-dichloro-9,10-dihydro-9,10-ethanoanthracen-11-yl)-N-methylmethanamine (6) as a homologue of the anxiolytic and antidepressant drugs benzoctamine and maprotiline were described. The key intermediate aldehydes (3) and (4) were successfully synthesized via a [4 + 2] cycloaddition between acrolein and 1,8-dichloroanthracene. The synthesized compounds were investigated for antidepressant activity using the forced swimming test. Compounds (5), (6) and (3) showed significant reduction in the mice immobility indicating significant antidepressant effects. These compounds significantly reduced the immobility times at a dose 80 mg/kg by 84.0%, 86.7% and 71.1% respectively.

23 September 2016 in Molecules
Verified
Journal Article
Open access
PDF file
MSMujeeb Sultan
Mujeeb Sultan
UKUsama Karama
Usama Karama
AIAlmansour Abdulrahman I
Almansour Abdulrahman I
Saied SolimanSaied Soliman
Saied Soliman
A theoretical study of the regioselectivity of the Diels-Alder reaction between 1,8-dichloroanthracene and acrolein is performed using DFT at the B3LYP/6-31G(d,p) level of theory. The FMO analysis, global and local reactivity indices confirmed the reported experimental results. Potential energy surface analysis showed that the cycloadditions (CAs) favor the formation of the anti product. These results are in good agreement with the reported results obtained experimentally where the anti is the major product.

3 November 2010 in Synthetic Communications
Verified
Journal Article
Closed access
UKUsama Karama
Usama Karama
(Carboethoxymethylene)triphenylphosphorane 1 can undergo the tandem reaction of iodination–oxidation–Wittig reaction with alcohol in the presence of N-iodosuccinimide (NIS) and manganese dioxide. The reaction constitutes a stereoselective one-pot procedure for the preparation of Z-configured α-iodo-α,β-unsaturated esters in good to excellent yield.

21 December 2012 in Synthetic Communications
Verified
Journal Article
Closed access
UKUsama Karama
Usama Karama
RMRefat Mahfouz
Refat Mahfouz
ZAZeid ALOthman
Zeid ALOthman
IWIsmail Warad
Ismail Warad
AAAbdulrahman Almansour
Abdulrahman Almansour
A simple one-pot process for in situ bromination of (ethoxycarbonylmethylene)-triphenylphosphorane 1 was carried out. This was followed by oxidation of alcohol using SO3. Pyridine complex as a mild oxidant and in situ trapping of the aldehyde. This process constitutes a stereoselective one-pot procedure for the preparation of Z-configured α-bromo-α, β-unsaturated esters in good yield.