21661-87-0Relevant academic research and scientific papers
Electrochemical Oxidative Functionalization of Arylalkynes: Access to α,α-Dibromo Aryl Ketones
Wang, Dan,Wan, Zhaohua,Zhang, Heng,Lei, Aiwen
, p. 1022 - 1027 (2021)
A general and effective protocol to synthesize α,α-dibromo aryl ketones has been developed via an electrochemical oxidative method. The reaction proceeds smoothly at room temperature in an undivided cell without the addition of external oxidants. In the reaction process, LiBr acts as both bromine source and supporting electrolyte. This electrooxidation strategy has good substrate applicability and functional group compatibility. Moreover, the reaction could be scaled up efficiently in a continuous flow cell. The target product could undergo further functionalization for the synthesis of some useful heterocyclic compounds. (Figure presented.).
Modular and Chemoselective Strategy for Accessing (Distinct) α,α-Dihaloketones from Weinreb Amides and Dihalomethyllithiums
Malik, Monika,Pace, Vittorio,Senatore, Raffaele,Touqeer, Saad,Urban, Ernst
supporting information, p. 5056 - 5061 (2020/10/21)
The selective transfer of diversely functionalized dihalomethyllithiums (LiCHBrCl, LiCHClI, LiCHBrI, LiCHCl2, LiCHBr2, LiCHFI) to Weinreb amides for preparing gem-dihaloketones in one synthetic operation is reported. The capability of these amides as acylating agents and, the wide availability of dihalomethanes as pronucleophiles, enable a straightforward route to the title compounds under full chemocontrol. No racemization phenomena were evidenced in the case of optically active materials. Additionally, tolerance to sensitive functional groups (esters, amides, halogens, olefins etc.) was uniformly noticed, thus making this conceptually intuitive strategy flexible and tunable by the operator. (Figure presented.).
Electrochemical Oxidative Oxydihalogenation of Alkynes for the Synthesis of α,α-Dihaloketones
Meng, Xiangtai,Zhang, Yu,Luo, Jinyue,Wang, Fei,Cao, Xiaoji,Huang, Shenlin
supporting information, p. 1169 - 1174 (2020/02/04)
An electrochemical oxydihalogenation of alkynes has been developed for the first time. Using this sustainable protocol, a variety of α,α-dihaloketones can be prepared with readily available CHCl3, CH2Cl2, ClCH2CH2Cl, and CH2Br2 as the halogen source under electrochemical conditions at room temperature.
Selective Debromination of α,α,α-Tribromomethylketones with HBr–H2O Reductive Catalytic System
Cheng, Zhao,Guo, Hongmei,Huang, Guozheng,Rexit, Abulikemu Abudu,Wang, Hui,Zheng, Meng-Xia
, p. 6455 - 6458 (2020/10/21)
A debromination of α,α,α-tribromomethylketones is developed for chemoselective synthesis of α-mono- and α,α-dibromomethylketones with high selectivity under H2O–HBr reductive conditions. This method offers an efficient and direct way to synthesize α-mono or α,α-dibromomethylketone compounds in high to excellent yields through the process of HBr self-circulation in water.
Visible-light-promoted oxidative halogenation of alkynes
Li, Yiming,Mou, Tao,Lu, Lingling,Jiang, Xuefeng
supporting information, p. 14299 - 14302 (2019/12/02)
In nature, halogenation promotes the biological activity of secondary metabolites, especially geminal dihalogenation. Related natural molecules have been studied for decades. In recent years, their diversified vital activities have been explored for treating various diseases, which call for efficient and divergent synthetic strategies to facilitate drug discovery. Here we report a catalyst-free oxidative halogenation achieved under ambient conditions (halide ion, air, water, visible light, room temperature, and normal pressure). Constitutionally, electron transfer between the oxygen and halide ion is shuttled via simple conjugated molecules, in which phenylacetylene works as both reactant and catalyst. Synthetically, it provides a highly compatible late-stage transformation strategy to build up dihaloacetophenones (DHAPs).
Silica gel catalyzed α-bromination of ketones using N-bromosuccinimide: An easy and rapid method
Mohan Reddy, Bodireddy,Venkata Ramana Kumar, Velpula,Chinna Gangi Reddy, Nallagondu,Mahender Rao, Siripragada
, p. 179 - 182 (2014/02/14)
An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide (NBS) catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time (5-20 min). Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents.
A tandem one-pot aqueous phase synthesis of thiazoles/selenazoles
Madhav,Narayana Murthy,Anil Kumar,Ramesh,Nageswar
experimental part, p. 3835 - 3838 (2012/08/14)
The first ever tandem one-pot synthetic protocol for the synthesis of thiazoles/selenazoles from alkynes via the formation of 2,2-dibromo-1- phenylethanone is reported. The reaction is catalyzed by β-cyclodextrin in aqueous medium and resulted in good yields.
Switching reversibility to irreversibility in glycogen synthase kinase 3 inhibitors: Clues for specific design of new compounds
Perez, Daniel I.,Palomo, Valle,Pérez, Concepción,Gil, Carmen,Dans, Pablo D.,Luque, F. Javier,Conde, Santiago,Martínez, Ana
experimental part, p. 4042 - 4056 (2011/08/05)
Development of kinase-targeted therapies for central nervous system (CNS) diseases is a great challenge. Glycogen synthase kinase 3 (GSK-3) offers a great potential for severe CNS unmet diseases, being one of the inhibitors on clinical trials for different tauopathies. Following our hypothesis based on the enhanced reactivity of residue Cys199 in the binding site of GSK-3, we examine here the suitability of phenylhalomethylketones as irreversible inhibitors. Our data confirm that the halomethylketone unit is essential for the inhibitory activity. Moreover, addition of the halomethylketone moiety to reversible inhibitors turned them into irreversible inhibitors with IC50 values in the nanomolar range. Overall, the results point out that these compounds might be useful pharmacological tools to explore physiological and pathological processes related to signaling pathways regulated by GSK-3 opening new avenues for the discovery of novel GSK-3 inhibitors.
Tandem oxidation/bromination of ethyl aromatics to α,α- dibromoacetophenones with molecular oxygen under visible light irradiation
Tada, Norihiro,Ban, Kazunori,Ishigami, Takafumi,Nobuta, Tomoya,Miura, Tsuyoshi,Itoh, Akichika
experimental part, p. 3821 - 3824 (2011/08/06)
The facile synthesis of α,α-dibromoacetophenones from ethyl-substituted aromatics by aerobic photooxidation has been developed. This synthetic method achieves oxidative dibromination of aromatic ethyl groups by using inexpensive and easily handled bromine sources, harmless visible light and molecular oxygen.
PHOTOINDUCED ALCOHOLYSIS OF alpha , alpha , alpha -TRIBROMACETOPHENONE TO BENZOYLFORMATE.
Izawa,Ishiguro,Tomioka
, p. 1490 - 1496 (2007/10/02)
Irradiation of p-substituted alpha , alpha , alpha -tribromoacetophenones (1) in O//2-saturated alcohols (MeOH, prim. and sec. alcohols) afforded a new alcoholysis product, benzoylformate (2), in good yield (75-85%) along with benzoate and radical (reduction) products. Sensitization experiments showed that 2 was derived from the triplet excited 1. Formation of 2 as well as the decomposition rate of 1 were greatly accelerated by oxygen, presumably as a result of the involvement of the normally forbidden S//o yields T//1 transition of 1 due to the oxygen-1 charge transfer complex. Independent synthesis and reaction of possible intermediates in the photoalcoholysis of 1 leading to 2 suggested that 2 was formed from spontaneous (dark) reactions of initial photoalcoholysis product, alpha alpha -dibromo- alpha -alkoxyacetophenone.
