90-99-3Relevant articles and documents
Visible Light-Catalyzed Benzylic C-H Bond Chlorination by a Combination of Organic Dye (Acr+-Mes) and N-Chlorosuccinimide
Xiang, Ming,Zhou, Chao,Yang, Xiu-Long,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
, p. 9080 - 9087 (2020/08/14)
By combining "N-chlorosuccinimide (NCS)"as the safe chlorine source with "Acr+-Mes"as the photocatalyst, we successfully achieved benzylic C-H bond chlorination under visible light irradiation. Furthermore, benzylic chlorides could be converted to benzylic ethers smoothly in a one-pot manner by adding sodium methoxide. This mild and scalable chlorination method worked effectively for diverse toluene derivatives, especially for electron-deficient substrates. Careful mechanistic studies supported that NCS provided a hydrogen abstractor "N-centered succinimidyl radical,"which was responsible for the cleavage of the benzylic C-H bond, relying on the reducing ability of Acr?-Mes.
Metal-free iodine-promoted direct synthesis of unsymmetrical triarylmethanes
Gu, Ying-Chun,Huang, Jie,Wu, Run-Shi,Xu, Da-Zhen,Yang, Qi,Yu, Ya-Qin
, p. 5519 - 5525 (2020/04/17)
A highly efficient strategy to synthesize completely unsymmetrical triarylmethanes promoted by iodine under metal-free conditions has been successfully developed. Three different aryl groups were introduced into triarylmethanes in a one-pot reaction from inexpensive and readily available salicylaldehydes, arylboronic acids and arenes via o-QM intermediates generated in situ, delivering a wide range of unsymmetrical triarylmethanes bearing various functional groups in good yields with excellent chemoselectivity.
Ferric chloride–catalyzed deoxygenative chlorination of carbonyl compounds: A comparison of chlorodimethylsilane and dichloromethylsilane system
Xing, Bing-Han,Zhao, Xuan-Xuan,Qin, Yu-Jun,Zhang, Pu,Guo, Zhi-Xin
, p. 667 - 675 (2020/05/22)
Deoxygenative chlorination of carbonyl compounds using the HMe2SiCl/FeCl3/EtOAc and HMeSiCl2/FeCl3/EtOAc systems has been systemically investigated. The HMe2SiCl-FeCl3 system showed the advantages of good substrate applicability, mild reaction conditions, simple operation, low cost, and easy availability of raw materials. Also, it provided a simple and efficient synthesis route for carbonyl deoxychlorination via a one-pot method. Using the HMeSiCl2/FeCl3/EtOAc system, the β-methylchalcone derivative could be obtained in good yields in addition to obtaining the chlorinated compound. Finally, two plausible reaction routes were proposed to describe the formation of the chlorinated compound and the β-methylchalcone derivative.
α-Diimine-Niobium Complex-Catalyzed Deoxychlorination of Benzyl Ethers with Silicon Tetrachloride
Parker, Bernard F.,Hosoya, Hiromu,Arnold, John,Tsurugi, Hayato,Mashima, Kazushi
supporting information, p. 12825 - 12831 (2019/10/19)
α-Diimine niobium complexes serve as catalysts for deoxygenation of benzyl ethers by silicon tetrachloride (SiCl4) to cleanly give two equivalents of the corresponding benzyl chlorides, where SiCl4 has the dual function of oxygen scavenger and chloride source with the formation of a silyl ether or silica as the only byproduct. The reaction mechanism has two successive trans-etherification steps that are mediated by the niobium catalyst, first forming one equivalent of benzyl chloride along with the corresponding silyl ether intermediate that undergoes the same reaction pathway to give the second equivalent of benzyl chloride and silyl ether.
Design, synthesis, and molecular docking study of new piperazine derivative as potential antimicrobial agents
Patil, Mahadev,Noonikara Poyil, Anurag,Joshi, Shrinivas D.,Patil, Shivaputra A.,Patil, Siddappa A.,Bugarin, Alejandro
supporting information, (2019/09/06)
Herein, we describe the successful design and synthesis of seventeen new 1,4-diazinanes, compounds commonly known as piperazines. This group of piperazine derivatives (3a-q) were fully characterized by 1H NMR, 13C NMR, FT-IR, and LCMS spectral techniques. The molecular structure of piperazine derivative (3h) was further established by single crystal X-ray diffraction analysis. All reported compounds were evaluated for their antibacterial and antifungal potential against five bacterial (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa) and two fungal strains (Candida albicans and Cryptococcus neoformans). The complete bacterial screening results are provided. As documented, piperazine derivative 3e performed the best against these bacteria. Additionally, data obtained during molecular docking studies are very encouraging with respect to potential utilization of these compounds to help overcome microbe resistance to pharmaceutical drugs, as explicitly noted in this manuscript.
Synthesis and evaluation of potent and selective MGL inhibitors as a glaucoma treatment
Alapafuja, Shakiru O.,Malamas, Michael S.,Shukla, Vidyanand,Zvonok, Alexander,Miller, Sally,Daily, Laura,Rajarshi, Girija,Miyabe, Christina Yume,Chandrashekhar, Honrao,Wood, JodiAnne,Tyukhtenko, Sergiy,Straiker, Alex,Makriyannis, Alexandros
, p. 55 - 64 (2018/11/23)
Monoacylglycerol lipase (MGL) inhibition provides a potential treatment approach to glaucoma through the regulation of ocular 2-arachidonoylglycerol (2-AG) levels and the activation of CB1 receptors. Herein, we report the discovery of new series of carbamates as highly potent and selective MGL inhibitors. The new inhibitors showed potent nanomolar inhibitory activity against recombinant human and purified rat MGL, were selective (>1000-fold) against serine hydrolases FAAH and ABHD6 and lacked any affinity for the cannabinoid receptors CB1 and CB2. Protein-based 1H NMR experiments indicated that inhibitor 2 rapidly formed a covalent adduct with MGL with a residence time of about 6 h. This interconversion process “intrinsic reversibility” was exploited by modifications of the ligand's size (length and bulkiness) to generate analogs with “tunable’ adduct residence time (τ). Inhibitor 2 was evaluated in a normotensive murine model for assessing intraocular pressure (IOP), which could lead to glaucoma, a major cause of blindness. Inhibitor 2 was found to decrease ocular pressure by ～4.5 mmHg in a sustained manner for at least 12 h after a single ocular application, underscoring the potential for topically-administered MGL inhibitors as a novel therapeutic target for the treatment of glaucoma.
Organocatalytic Chlorination of Alcohols by P(III)/P(V) Redox Cycling
Longwitz, Lars,Jopp, Stefan,Werner, Thomas
, p. 7863 - 7870 (2019/06/27)
A catalytic system for the chlorination of alcohols under Appel conditions was developed. Benzotrichloride is used as a cheap and readily available chlorinating agent in combination with trioctylphosphane as the catalyst and phenylsilane as the terminal reductant. The reaction has several advantages over other variants of the Appel reaction, e.g., no additional solvent is required and the phosphane reagent is used only in catalytic amounts. In total, 27 different primary, secondary, and tertiary alkyl chlorides were synthesized in yields up to 95%. Under optimized conditions, it was also possible to convert epoxides and an oxetane to the dichlorinated products.
Ruthenium-Catalyzed Reductive Arylation of N-(2-Pyridinyl)amides with Isopropanol and Arylboronate Esters
Ronson, Thomas O.,Renders, Evelien,Van Steijvoort, Ben F.,Wang, Xubin,Wybon, Clarence C. D.,Prokopcová, Hana,Meerpoel, Lieven,Maes, Bert U. W.
, p. 482 - 487 (2019/01/04)
A new three-component reductive arylation of amides with stable reactants (iPrOH and arylboronate esters), making use of a 2-pyridinyl (Py) directing group, is described. The N-Py-amide substrates are readily prepared from carboxylic acids and PyNH2, and the resulting N-Py-1-arylalkanamine reaction products are easily transformed into the corresponding chlorides by substitution of the HN-Py group with HCl. The 1-aryl-1-chloroalkane products allow substitution and cross-coupling reactions. Therefore, a general protocol for the transformation of carboxylic acids into a variety of functionalities is obtained. The Py-NH2 by-product can be recycled.
Manganese-salen catalyzed oxidative benzylic chlorination
Sasmal, Sheuli,Rana, Sujoy,Lahiri, Goutam Kumar,Maiti, Debabrata
, (2018/07/14)
Abstract: Metalloporphyrins are well-known to serve as the model for mimicking reactivities exhibited by cytochrome P450 hydroxylase. Recent developments on selective C–H halogenation using Mn-porphyrins provided the way for understanding the reactivity as well as mechanism of different halogenase enzymes. In this report, we demonstrated a method for benzylic C–H chlorination using easily prepared Mn(salen) complex as the catalyst, which shows a complementary reactivity of Mn-porphyrins. Here, NaOCl has been used as a chlorinating source as well as the oxidant. Efforts towards understanding the mechanism suggested the formation of the high-valent Mn(V)=O species which is believed to be the key intermediate to conduct this transformation. Graphical abstract: SYNOPSIS Mn(salen)-catalyzed selective benzylic chlorination protocol has been developed using aqueous NaOCl solution. Reactions proceeded efficiently at room temperature and displayed good functional group tolerance. The mechanistic investigation demonstrated that Mn (V) = O species is likely to be the key intermediate which is responsible to generate benzylic radical. EPR and ESI-MS studies confirmed the in situ formation of Mn(IV)-species.[Figure not available: see fulltext.].
Systematic Evaluation of Sulfoxides as Catalysts in Nucleophilic Substitutions of Alcohols
Motsch, Sebastian,Schütz, Christian,Huy, Peter H.
supporting information, p. 4541 - 4547 (2018/09/13)
Herein, a method for the nucleophilic substitution (SN) of benzyl alcohols yielding chloro alkanes is introduced that relies on aromatic sulfoxides as Lewis base catalysts (down to 1.5 mol-%) and benzoyl chloride (BzCl) as reagent. A systematic screening of various sulfoxides and other sulfinyl containing Lewis bases afforded (2-methoxyphenyl)methyl sulfoxide as optimal catalyst. In contrast to reported formamide catalysts, sulfoxides also enable the application of plain acetyl chloride (AcCl) as reagent. In addition, it was demonstrated that weakly electrophilic carboxylic acid chlorides like BzCl promote Pummerer rearrangement of sulfoxides already at room temperature. This side-reaction also provided the explanation, why sulfoxide catalyzed SN-reactions of alcohols do not allow the effective production of aliphatic and electron deficient chloro alkanes. Comparison experiments provided further insight into the reaction mechanism.
