- Novel and efficient bridged bis(N-heterocyclic carbene)palladium(II) catalysts for selective carbonylative Suzuki–Miyaura coupling reactions to biaryl ketones and biaryl diketones
-
Bridged N,N′-substituted bisbenzimidazolium bromide salts (L1, L2, and L3) were synthesized and fully characterized. Reactions of palladium acetate with L1, L2, and L3 afforded corresponding new bridged bis(N-heterocyclic carbene)palladium(II) complexes (C1, C2, and C3) in high yields. The X-ray structure of complex C1 showed that the Pd(II) ion is bonded to the two carbon atoms of the bis(N-heterocyclic carbene) and two bromido ligands are in the cis position, resulting in a distorted square planar geometry. The three Pd(NHC)2Br2 complexes C1, C2, and C3 were evaluated in carbonylative Suzuki–Miyaura coupling reactions of aryl boronic acids with aryl halides and displayed high catalytic activity with low catalyst loading. The coupling reactions of aryl bromides were selective towards the carbonylation product at higher carbon monoxide pressure.
- El Ali, Bassam,Fettouhi, Mohammed,Mansour, Waseem
-
-
- Synthesis and biochemical evaluation of benzoylbenzophenone thiosemicarbazone analogues as potent and selective inhibitors of cathepsin L
-
Upregulation of cathepsin L in a variety of tumors and its ability to promote cancer cell invasion and migration through degradation of the extracellular matrix suggest that cathepsin L is a promising biological target for the development of anti-metastatic agents. Based on encouraging results from studies on benzophenone thiosemicarbazone cathepsin inhibitors, a series of fourteen benzoylbenzophenone thiosemicarbazone analogues were designed, synthesized, and evaluated for their inhibitory activity against cathepsins L and B. Thiosemicarbazone inhibitors 3-benzoylbenzophenone thiosemicarbazone 1, 1,3-bis(4-fluorobenzoyl)benzene thiosemicarbazone 8, and 1,3-bis(2-fluorobenzoyl)-5-bromobenzene thiosemicarbazone 32 displayed the greatest potency against cathepsin L with low IC50 values of 9.9 nM, 14.4 nM, and 8.1 nM, respectively. The benzoylbenzophenone thiosemicarbazone analogues evaluated were selective in their inhibition of cathepsin L compared to cathepsin B. Thiosemicarbazone analogue 32 inhibited invasion through Matrigel of MDA-MB-231 breast cancer cells by 70% at 10 μM. Thiosemicarbazone analogue 8 significantly inhibited the invasive potential of PC-3ML prostate cancer cells by 92% at 5 μM. The most active cathepsin L inhibitors from this benzoylbenzophenone thiosemicarbazone series (1, 8, and 32) displayed low cytotoxicity toward normal primary cells [in this case human umbilical vein endothelial cells (HUVECs)]. In an initial in vivo study, 3-benzoylbenzophenone thiosemicarbazone (1) was well-tolerated in a CDF1 mouse model bearing an implanted C3H mammary carcinoma, and showed efficacy in tumor growth delay. Low cytotoxicity, inhibition of cell invasion, and in vivo tolerability are desirable characteristics for anti-metastatic agents functioning through an inhibition of cathepsin L. Active members of this structurally diverse group of benzoylbenzophenone thiosemicarbazone cathepsin L inhibitors show promise as potential anti-metastatic, pre-clinical drug candidates.
- Parker, Erica N.,Song, Jiangli,Kishore Kumar,Odutola, Samuel O.,Chavarria, Gustavo E.,Charlton-Sevcik, Amanda K.,Strecker, Tracy E.,Barnes, Ashleigh L.,Sudhan, Dhivya R.,Wittenborn, Thomas R.,Siemann, Dietmar W.,Horsman, Michael R.,Chaplin, David J.,Trawick, Mary Lynn,Pinney, Kevin G.
-
p. 6974 - 6992
(2015/11/11)
-
- COMPOSITIONS AND METHODS FOR INHIBITION OF CATHEPSINS
-
This invention is directed to compound of Formula I and methods of using these compounds in the treatment of conditions in which modulation of a cathepsin, particularly cathepsin K or cathepsin L, will be therapeutically useful.
- -
-
Paragraph 0135
(2013/10/08)
-
- Catalytic Friedel-Crafts acylation and benzoylation of aromatic compounds using activated hematite as a novel heterogeneous catalyst
-
Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes such as chlorobenzene and nitrobenzene have been successfully carried out using activated hematite (α-Fe2O3) as a new, heterogeneous and green catalyst. Sonication of neat α-Fe2O3 in a water bath under air atmosphere at room temperature followed by heating at 200°C, dramatically increase the activity of α-Fe2O 3. With the catalyst loading as low as 5.0mol%, a wide variety of benzene derivatives were easily converted into the corresponding acylated products in a clean and high-yielding acylation reaction. It was found that the activated α-Fe2O3 could be efficiently recycled and reused several times by simple washing with ethyl acetate, this cannot be attained with most of the traditional catalysts. Copyright
- Sharghi, Hashem,Jokar, Mahboubeh,Doroodmand, Mohammad Mahdi,Khalifeh, Reza
-
experimental part
p. 3031 - 3044
(2011/02/21)
-
- Efficient catalyst-free bi- and triaroylation of aromatic rings in a single step
-
(Chemical Equation Presented) The exceptional leaving group ability of the trimethylstannyl group in electrophilic aromatic substitutions makes possible the synthesis, in a single step, of bi- and triaroylarenes through the catalyst-free, regioselective reaction of bi- and tristannylarenes with different aroyl halides in o-dichlorobenzene as solvent. Specific di- and triketones are obtained in good to excellent yields (45-83%).
- Lo Fiego, Marcos J.,Badajoz, Mercedes A.,Silbestri, Gustavo F.,Lockhart, Maria T.,Chopa, Alicia B.
-
supporting information; scheme or table
p. 9184 - 9187
(2009/04/11)
-
- Atom-efficient cross-coupling reactions of triarylbismuths with acyl chlorides under Pd(0) catalysis
-
The atom-efficient cross-coupling reaction of triarylbismuths with a variety of aliphatic, aromatic, and hetero-aromatic acyl chlorides was demonstrated to afford high yields of cross-coupled ketones under palladium catalysis. The corresponding cross-coupling reaction with diacid chlorides also furnished bis-coupled ketones in good yields.
- Rao, Maddali L.N.,Venkatesh, Varadhachari,Banerjee, Debasis
-
p. 12917 - 12926
(2008/03/28)
-