60405-63-2Relevant academic research and scientific papers
Design, synthesis, and in vitro evaluation of 4-aminoalkyl-1(2H)-phthalazinones as potential multifunctional anti-Alzheimer's disease agents
Ye, Chanyuan,Xu, Rui,Cao, Zhongcheng,Song, Qing,Yu, Guangjun,Shi, Yichun,Liu, Zhuoling,Liu, Xiuxiu,Deng, Yong
, (2021/04/22)
A series of 4-aminoalkyl-1(2H)-phthalazinone derivatives was designed and synthesized as potential multifunctional agents for Alzheimer's disease (AD) treatment. In vitro biological assay results demonstrated that most synthesized compounds exhibited sign
A facile, efficient and selective deprotection of p-methoxy benzyl ethers using zinc (Ii) trifluoromethanesulfonate
Chandrasekhar, Choragudi,Rao, Mannam Subba,Sireesha, Reddymasu,Sreenivasulu, Reddymasu
, p. 955 - 958 (2019/11/22)
Deprotection is significant and conducted over mild reaction conditions, in order to restrict any more side reactions with sensitive functional groups as well as racemization or epimerization of stereo center because the protective groups are often cleaved at last stage in the synthesis. P-Methoxy benzyl (PMB) ether appears unique due to its easy introduction and removal than the other benzyl ether protecting groups. A facile, efficient and highly selective cleavage of P-methoxy benzyl ethers was reported by using 20 mole% Zinc (II) Trifluoromethanesulfonate at room temperature in acetonitrile solvent over 15-120 min. time period. To study the generality of this methodology, several PMB ethers were prepared from a variety of substrates having different protecting groups and subjected to deprotection of PMB ethers using Zn(OTf)2 in acetonitrile. In this methodology, zinc triflate cleaves only PMB ethers without affecting acid sensitivity, base sensitivity and also chiral epoxide groups.
Oxidative Deprotection of p-Methoxybenzyl Ethers via Metal-Free Photoredox Catalysis
Ahn, Deok Kyun,Kang, Young Woo,Woo, Sang Kook
, p. 3612 - 3623 (2019/03/11)
An efficient and greener deprotection method for p-methoxybenzyl (PMB) ethers using a metal-free visible light photoredox catalyst and air and ammonium persulfate as the terminal oxidants is presented. Various functional groups and protecting groups were tolerated in the developed method to achieve good to excellent yields in short reaction times. Significantly, the developed method was compatible with PMB ethers derived from primary, secondary, and tertiary alcohols and a gram-scale reaction. Mechanistic studies support a proposed reaction mechanism that involves single electron oxidation of the PMB ether.
Highly Chemoselective Deprotection of the 2,2,2-Trichloroethoxycarbonyl (Troc) Protecting Group
Trost, Barry M.,Kalnmals, Christopher A.,Tracy, Jacob S.,Bai, Wen-Ju
, p. 8043 - 8046 (2019/01/04)
Nonreducing, pH-neutral conditions for the selective cleavage of the 2,2,2-trichloroethoxycarbonyl (Troc) protecting group are reported. Using trimethyltin hydroxide in 1,2-dichloroethane, Troc-protected alcohols, thiols, and amines can be selectively unmasked in the presence of various functionalities that are incompatible with the reducing conditions traditionally used to remove the Troc group. This mild deprotection protocol tolerates a variety of other hydrolytically sensitive and acid/base-sensitive moieties as well.
A microwave-assisted highly practical chemoselective esterification and amidation of carboxylic acids
Pathak, Gunindra,Das, Diparjun,Rokhum, Lalthazuala
, p. 93729 - 93740 (2016/10/21)
The ubiquitousness of esters and amide functionalities makes their coupling reaction one of the most sought-after organic transformations. Herein, we have described an efficient microwave-assisted synthesis of esters and amides. Soluble triphenylphosphine, in conjugation with molecular iodine, gave the desired products without the requirement for a base/catalyst. In addition, a solid-phase synthetic route is incorporated for the said conversion, which has added advantages over solution-phase pathways, such as low moisture sensitivity, easy handling, isolation of the product by simple filtration, and reusability. In short, our method is simple, mild, green, and highly chemoselective in nature.
Selective Monoesterification of Symmetrical Diols Using Resin-Bound Triphenylphosphine
Pathak, Gunindra,Rokhum, Lalthazuala
supporting information, p. 483 - 487 (2015/09/22)
Coupling reactions to make esters and amides are among the most widely used organic transformations. We report efficient procedures for amide bond formation and for the monoesterification of symmetrical diols in excellent yields without any requirement for high dilution or slow addition using resin-bound triarylphosphonium iodide. Easy purification, low moisture sensitivity, and good to excellent yields of the products are the major advantages of this protocol.
Investigation of the origin and synthetic application of the pseudodilution effect for Pd-catalyzed macrocyclisations in concentrated solutions with immobilized catalysts
Brehm, Elisabeth,Breinbauer, Rolf
supporting information, p. 4750 - 4756 (2013/07/26)
Immobilized Pd-complexes allowed macrocyclisations via the Tsuji-Trost-reaction in concentrated solutions. Systematic studies suggest that the origin of this pseudodilution effect is neither film diffusion nor gel diffusion, but the reduction in conformational freedom of intermediates and intramolecular prenucleophile activation. In contrast a pseudodilution effect could not be observed for Sonogashira- and Suzuki-macrocyclisations.
Aerobic oxidative deprotection of benzyl-type ethers under atmospheric pressure catalyzed by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)/tert-butyl nitrite
Shen, Zhenlu,Sheng, Lili,Zhang, Xiaochu,Mo, Weimin,Hu, Baoxiang,Sun, Nan,Hu, Xinquan
, p. 1579 - 1583 (2013/03/28)
A facile and efficient protocol for the oxidative deprotection of benzyl-type ethers has been developed. The reaction was performed with catalytic amounts of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert-butyl nitrite (TBN) under atmospheric pressure of O2. Under the optimal reaction conditions, a variety of p-methoxybenzyl (PMB), p-phenylbenzyl (PPB), and benzyl (Bn) ethers can be deprotected to their corresponding alcohols in excellent conversions and selectivities.
Rate-acceleration in gold-nanocluster-catalyzed aerobic oxidative esterification using 1,2- and 1,3-diols and their derivatives
Yasukawa, Tomohiro,Miyamura, Hiroyuki,Kobayashi, Shu
experimental part, p. 621 - 627 (2011/10/12)
Aerobic oxidation of aldehydes to 1,2- and 1,3-diol monoesters was catalyzed by polymer-incarcerated gold nanoclusters under ambient conditions. The esterification proceeded much faster with 1,2- and 1,3-diols and their derivatives rather than with methanol. Magnum PI: Gold-nanocluster catalysts, PI-Au, that were immobilized on polystyrene-based polymers with cross-linking moieties, were used to catalyze the syntheses of 1,2 and 1,3-diol monoesters and their derivatives from aldehydes. The effect of neighboring-group participation in the esterification reaction is also described. Copyright
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone ((DDQ)/tert-butyl nitrite/oxygen: A versatile catalytic oxidation system
Shen, Zhenlu,Dai, Jialiang,Xiong, Jie,He, Xijun,Mo, Weimin,Hu, Baoxiang,Sun, Nan,Hu, Xinquan
experimental part, p. 3031 - 3038 (2012/01/02)
A new catalytic oxidation system using catalytic amounts of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert-butyl nitrite with molecular oxygen serving as the environmentally benign, terminal oxidant has been developed. This aerobic catalytic system was established for the selective oxidation of non-sterically hindered benzylic alcohols and electron-rich benzyl methyl ethers, and successfully extended to an application in the oxidative deprotection of PMB ethers to the alcohols in high selectivity. Copyright
