Publications by authors named "Kamal M El Shaieb"

Our investigation includes the synthesis of new naphthalene-bis-triazole-bis-quinolin-2(1H)-ones 4a−e and 7a−e via Cu-catalyzed [3 + 2] cycloadditions of 4-azidoquinolin-2(1H)-ones 3a−e with 1,5-/or 1,8-bis(prop-2-yn-1-yloxy)naphthalene (2) or (6). All structures of the obtained products have been confirmed with different spectroscopic analyses. Additionally, a mild and versatile method based on copper-catalyzed [3 + 2] cycloaddition (Meldal−Sharpless reaction) was developed to tether quinolinones to O-atoms of 1,5- or 1,8-dinaphthols.

View Article and Find Full Text PDF

The reactions of dialkyl acetylenedicarboxylates with various 2-oxo-acenaphthoquinylidene- and 4-acetyl[2.2]paracyclophanylidene-thiosemicarbazones were investigated. Using simple experimental procedures, 1,3-Thiazolidin-4-ones derived from acenaphthequinone or [2.

View Article and Find Full Text PDF

A large number of natural products containing the propellane scaffold have been reported to exhibit cytotoxicity against several cancers; however, their mechanism of action is still unknown. Anticancer drugs targeting DNA are mainly composed of small planar molecule/s that can interact with the DNA helix, causing DNA malfunction and cell death. The aim of this study was to design and synthesize propellane derivatives that can act as DNA intercalators and/or groove binders.

View Article and Find Full Text PDF

Zwitterions formed from the addition of triphenylphosphine to dialky acetylene-dicarboxylates attack the nucleus of both 1H-perimidine (1) and 1H-benzo[d]imidazole (9) to form novel pyrido[1,2,3-cd]perimidine and imidazo[4,5,1-ij]quinoline derivatives in moderate yields (64-72%). The biological activity of the products has been studied. Compound 3a was found to extend life span of wild type Caenorhabditis elegans under standard laboratory conditions.

View Article and Find Full Text PDF

Reactions of N,N;-disubstituted hydrazinecarbothioamides 8a-c and substituted thioureidoethylthioureas 9a-c with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil, 10a) and 2,3,5,6-tetrabromo-1,4-benzoquinone (bromanil, 10b) to form N,N;-disubstituted [1,3,4]thiadiazole-2,5-diamines 11a-c, 6,7-dichloro-3-substituted amino-1H-benzo[1,3,4]- thiadiazine-5,8-diones 12a-c, 2,3,7,8-tetrahalothianthrene-1,4,6,9-tetraones 13a,b, 5,6,8- trihalo-7-oxo-3,7-dihydro-2H-quinoxaline-1-carbothioic acid substituted amides 14a-c, 15a-c and 7-substituted imino-[1,3,6]thiadiazepane-3-thiones 16a-c are reported. Rationales for the observed conversions are presented.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_session4uom2v7m3unlljorf6i4fu5cmkf01bqr): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once