2033-81-0Relevant academic research and scientific papers
Regioselective Hydroalkylation of Vinylarenes by Cooperative Cu and Ni Catalysis
Ravn, Anne K.,Johansen, Martin B.,Skrydstrup, Troels
supporting information, (2021/12/14)
Disclosed here is a dual copper and nickel catalytic system with a silyl hydride source for promoting the linear selective hydroalkylation of vinylarenes. This carbon–carbon bond-forming protocol is applied to couple a variety of functionalized vinylarenes with alkyl halides applying a nickel(II) NNN pincer complex in the presence of an NHC-ligated copper catalyst. This combination allows for a 1 mol % loading of the nickel catalyst leading to turnover numbers of up to 72. Over 40 examples are presented, including applications for pharmaceutical diversification. Labeling experiments demonstrated the regioselectivity of the reaction and revealed that the copper catalyst plays a crucial role in enhancing the rate for formation of the reactive linear alkyl nickel complex. Overall, the presented work provides a complimentary approach for hydroalkylation reactions, whilst providing a preliminary mechanistic understanding of the cooperativity between the copper and nickel complexes.
Pyrimidine-2,4-diamines as antiplasmodial antifolates
Seanego, Tswene D.,Klein, Hanna F.,Jansen van Vuuren, Natasha C.,Van Zyl, Robyn L.,Rousseau, Amanda L.
, p. 344 - 361 (2020/10/30)
Two series of substituted pyrimidine-2,4-diamines with a flexible side chain at either the 5- or 6-position of the pyrimdine ring were designed as potential inhibitors of P. falciparum dihydrofolate reductase (DHFR). The compounds were synthesised and eva
Nickel-Catalyzed Multicomponent Coupling Reaction of Alkyl Halides, Isocyanides and H2O: An Expedient Way to Access Alkyl Amides
Li, Qiao,Jin, Hongwei,Liu, Yunkui,Zhou, Bingwei
supporting information, p. 3466 - 3472 (2020/09/15)
We herein describe a Ni-catalyzed multicomponent coupling reaction of alkyl halides, isocyanides, and H2O to access alkyl amides. Bench-stable NiCl2(dppp) is competent to initiate this transformation under mild reaction conditions, thus allowing easy operation and adding practical value. Substrate scope studies revealed a broad functional group tolerance and generality of primary and secondary alkyl halides in this protocol. A plausible catalytic cycle via a SET process is proposed based on preliminary experiments and previous literature.
Structure-activity relationships of imidazothiazinones and analogs as antagonists of the cannabinoid-activated orphan G protein-coupled receptor GPR18
Schoeder, Clara T.,Kaleta, Maria,Mahardhika, Andhika B.,Olejarz-Maciej, Agnieszka,?a?ewska, Dorota,Kie?-Kononowicz, Katarzyna,Müller, Christa E.
, p. 381 - 397 (2018/06/14)
GPR18 is a cannabinoid-activated orphan G protein-coupled receptor (GPCR) that is selectively expressed on immune cells. Despite its significant potential as a drug target for inflammatory diseases and cancer immunotherapy, only very few GPR18 ligands have been described to date. In the present study we investigated the structure-activity relationships (SARs) of (Z)-2-(3-(4-chlorobenzyloxy)benzylidene)-6,7-dihydro-2H-imidazo[2,1-b][1,3]thiazin-3(5H)-one (PSB-CB5, 5), the most potent GPR18 antagonist described to date. Analogs were synthesized that exhibit broad modifications of the heterocyclic core and/or variation of substituents at the benzylidene moiety. The compounds were investigated in β-arrestin recruitment assays as inhibitors of human GPR18 activation by tetrahydrocannabinol (THC). Selectivity was assessed versus the cannabinoid receptors (CB1 and CB2) and versus GPR55, another orphan GPCR that interacts with cannabinoids. Phenyloxyalkyloxy-substituted benzylidenethiazinones with long alkyl chains (optimal length: hexamethylene) efficiently blocked GPR18 with similarly high potency as lead structure 5. (Z)-2-(3-(6-(4-Chlorophenoxy)hexyloxy)benzylidene)-6,7-dihydro-2H-imidazo[2,1-b][1,3]thiazin-3(5H)-one (PSB-CB-27, 23) exhibited the best profile: it displayed an IC50 value of 650 nM at GPR18 and showed improved selectivity versus CB receptors as compared to lead structure 5. Importantly, in contrast to 5, which showed only partial inhibition (60%), 23 led to a complete blockade of THC-induced GPR18 activation and is thus a superior tool for target validation. In addition, several compounds, e.g. 18 and 22, were identified as dual GPR18/GPR55 antagonists with similar potency at both targets, and selectivity versus CB receptors.
Nickel-Catalyzed Reductive Amidation of Unactivated Alkyl Bromides
Serrano, Eloisa,Martin, Ruben
supporting information, p. 11207 - 11211 (2016/10/13)
A user-friendly, nickel-catalyzed reductive amidation of unactivated primary, secondary, and tertiary alkyl bromides with isocyanates is described. This catalytic strategy offers an efficient synthesis of a wide range of aliphatic amides under mild conditions and with an excellent chemoselectivity profile while avoiding the use of stoichiometric and sensitive organometallic reagents.
Efficacy of novel phenoxyalkyl pyridinium oximes as brain-penetrating reactivators of cholinesterase inhibited by surrogates of sarin and VX
Chambers, Janice E.,Chambers, Howard W.,Funck, Kristen E.,Meek, Edward C.,Pringle, Ronald B.,Ross, Matthew K.
, p. 154 - 159 (2016/12/06)
Pyridinium oximes are strong nucleophiles and many are effective reactivators of organophosphate-inhibited cholinesterase (ChE). However, the current oxime reactivators are ineffective at crossing the blood-brain barrier and reactivating brain ChE in the intact organism. Our laboratories have developed a series of substituted phenoxyalkyl pyridinium oximes (US patent 9,227,937 B2) with the goal of identifying reactivators effective in crossing the blood-brain barrier. The first 35 of the series were found to have similar in?vitro efficacy as reactivators of ChE inhibited by a sarin surrogate (phthalimidyl isopropyl methylphosphonate, PIMP) or a VX surrogate (nitrophenyl ethyl methylphosphonate, NEMP) in bovine brain preparations as previously observed in rat brain preparations. A number of these novel oximes have shown the ability to decrease the level of ChE inhibition in the brains of rats treated with a high sublethal dosage of either a sarin surrogate (nitrophenyl isopropyl methylphosphonate, NIMP) or the VX surrogate NEMP. Levels of reactivation at 2?h after oxime administration were up to 35% while the currently approved therapeutic, 2-PAM, yielded no reduction in brain ChE inhibition. In addition, there was evidence of attenuation of seizure-like behavior with several of the more effective novel oximes, but not 2-PAM. Therefore these novel oximes have demonstrated an ability to reactivate inhibited ChE in brain preparations from two species and in?vivo data support their ability to enter the brain and provide a therapeutic action. These novel oximes have the potential to be developed into improved antidotes for nerve agent therapy.
Synthesis and biological evaluation of vinyl ether-containing azole derivatives as inhibitors of Trichophyton rubrum
Wang, Lulu,Yang, Wenge,Wang, Kai,Zhu, Jing,Shen, Fei,Hu, Yonghong
scheme or table, p. 4887 - 4890 (2012/08/07)
In an attempt to search for many target compounds with excellent activities, a series of vinyl ether-containing azole derivatives were designed, synthesized, and evaluated as antifungal agents. Results of preliminary antifungal tests against Trichophyton rubrum in vitro indicated that most of the synthesized compounds showed excellent activities. In comparison with fluconazole, itraconazole, voriconazole, omoconazole and amphotericin B, several compounds (such as 7d, 7g and 7h) exhibited more potent inhibitory activities, suggesting that they were promising leads for the development of novel antifungal agents.
Expeditious synthesis and biological evaluation of novel 2,N 6-disubstituted 1,2-dihydro-1,3,5-triazine-4,6-diamines as potential antimalarials
Gravestock, David,Rousseau, Amanda L.,Lourens, Anna C.U.,Moleele, Simon S.,Van Zyl, Robyn L.,Steenkamp, Paul A.
experimental part, p. 2022 - 2030 (2011/06/21)
A small set of novel 2,N6-disubstituted 1,2-dihydro-1,3,5- triazine-4,6-diamines was prepared possessing a flexible tether between the exocyclic nitrogen bonded to C-6 of the 1,2-dihydro-1,3,5-triazine-4,6-diamine heterocycle and the distal ary
Synthesis and biological evaluation of a new series of berberine derivatives as dual inhibitors of acetylcholinesterase and butyrylcholinesterase
Huang, Ling,Luo, Zonghua,He, Feng,Lu, Jing,Li, Xingshu
experimental part, p. 4475 - 4484 (2010/08/22)
A series of novel berberine derivatives were designed, synthesized, and biologically evaluated as inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Among these derivatives, compound 48a, berberine linked with 3-methylpyridi
Synthesis and insecticidal activity of novel carbamate derivatives as potential dual-binding site acetylcholinesterase inhibitors
Ma, Hong-Ju,Xie, Ru-Liang,Zhao, Qian-Fei,Mei, Xiang-Dong,Ning, Jun
experimental part, p. 12817 - 12821 (2011/10/09)
In biological systems, bivalent ligands often possess increased functional affinity for their receptors compared with monovalent ligands. On the basis of the structure of acetylcholinesterase (AChE), a series of novel carbamate heterodimetic derivatives w
