56578-54-2Relevant academic research and scientific papers
Solid state aldol reactions of solvated and unsolvated lithium pinacolone enolate aggregates
Pang, Huan,Williard, Paul G.
, (2020/01/13)
We reported the first systematic study of the solid-state aldol reactions of solvated and unsolvated lithium pinacolone enolate with a variety of solid aromatic aldehydes utilizing a mortar and pestle condition in comparison with the simple ball milling condition or tetrahydrofuran (THF) solution condition. In solution, the reactions are highly-selective with the aldol condensation product at room temperature. Under the condition of mortar and pestle, the reactions with unsolvated lithium pinacolone enolate showed the mixture of aldol condensation product and aldol addition product at room temperature. With the usage of solvated lithium pinacolone enolate, higher yields for most substrates were obtained. Furthermore, repeating the reactions under a simple ball billing condition with no other precautions at room temperature, we achieved high selectivity and yield of products for all substrates, indicating the powerful ability and the utility of solid-state, mechanochemical aldol reaction conditions.
Discovery of trisubstituted pyrazolines as a novel scaffold for the development of selective phosphodiesterase 5 inhibitors
Abdel-Halim, Mohammad,Tinsley, Heather,Keeton, Adam B.,Weam, Mohammed,Atta, Noha H.,Hammam, Mennatallah A.,Hefnawy, Amr,Hartmann, Rolf W.,Engel, Matthias,Piazza, Gary A.,Abadi, Ashraf H.
, (2020/10/12)
Celecoxib, is a selective cyclooxygenase-2 (COX2) inhibitor with a 1,5-diaryl pyrazole scaffold. Celecoxib has a better safety profile compared to other COX2 inhibitors having side effects of systemic hypertension and thromboembolic complications. This may be partly attributed to an off-target activity involving phosphodiesterase 5 (PDE5) inhibition and the potentiation of NO/cGMP signalling allowing coronary vasodilation and aortic relaxation. Inspired by the structure of celecoxib, we synthesized a chemically diverse series of compounds containing a 1,3,5-trisubstituted pyrazoline scaffold to improve PDE5 inhibitory potency, while eliminating COX2 inhibitory activity. SAR studies for PDE5 inhibition revealed an essential role for a carboxylic acid functionality at the 1-phenyl and the importance of the non-planar pyrazoline core over the planar pyrazole with the 5-phenyl moiety tolerating a range of substituents. These modifications led to new PDE5 inhibitors with approximately 20-fold improved potency to inhibit PDE5 and no COX-2 inhibitory activity compared with celecoxib. PDE isozyme profiling of compound 11 revealed a favorable selectivity profile. These results suggest that trisubstituted pyrazolines provide a promising scaffold for further chemical optimization to identify novel PDE5 inhibitors with potential for less side effects compared with available PDE5 inhibitors used for the treatment of penile erectile dysfunction and pulmonary hypertension.
Trisubstituted and tetrasubstituted pyrazolines as a novel class of cell-growth inhibitors in tumor cells with wild type p53
Abdel-Halim, Mohammad,Keeton, Adam B.,Gurpinar, Evrim,Gary, Bernard D.,Vogel, Simon M.,Engel, Matthias,Piazza, Gary A.,Boeckler, Frank M.,Hartmann, Rolf W.,Abadi, Ashraf H.
, p. 7343 - 7356 (2013/11/19)
Derivatives with scaffolds of 1,3,5-tri-substituted pyrazoline and 1,3,4,5-tetra-substituted pyrazoline were synthesized and tested for their inhibitory effects versus the p53+/+ HCT116 and p53-/- H1299 human tumor cell lines. Severa
Controlling the molecular topology of vinylogous iminium ions by logical substrate design: Highly regio- and stereoselective aminocatalytic 1,6-addition to linear 2,4-dienals
Silvi, Mattia,Chatterjee, Indranil,Liu, Yiankai,Melchiorre, Paolo
supporting information, p. 10780 - 10783 (2013/10/22)
All about topology control: The title reaction yields valuable tetrahydrofuran spirooxindoles (see scheme; TMS=trimethylsilyl), and exemplifies a rare asymmetric 1,6-addition to linear 2,4-dienals proceeding with high δ-site- and stereoselectivity. A steering group at the β-dienal position ensured molecular preorganization of the catalytically active vinylogous iminium ion intermediate for highly predictable reaction outcomes. Copyright
