970-85-4Relevant academic research and scientific papers
Mild, Metal-Free and Protection-Free Transamidation of N-Acyl-2-piperidones to Amino Acids, Amino Alcohols and Aliphatic Amines and Esterification of N-Acyl-2-piperidones
Subramani, Muthuraman,Rajendran, Saravana Kumar
, p. 3677 - 3686 (2019/06/08)
Amides are indispensable building blocks of biological systems, pharmaceuticals, and materials. We report a highly selective method for the synthesis of amides via transamidation process. Transamidation of N-acyl-2-piperidones with a broad range of amines is demonstrated under exceedingly mild and metal-free reaction condition that relies on the amide bond twist to weaken the amidic resonance. Transamidation proceeds under the neat condition at room temperature, in short reaction times (30–90 min) with good yields. Considerable variation is tolerated with both amine and imide substrates. Of note, amines bearing carboxylic acids (glycine and serine) and hydroxyl groups (dopamine, tyramine, etc.) are well tolerated which are otherwise problematic under the metal-catalyzed protocol. Our current method is applicable for transamidation of both alkyl and aryl-N-acyl-2-piperidones. The practical value of the method is highlighted by the synthesis of four natural product amide alkaloids in high yields under mild reaction conditions. In the absence of nucleophilic amines, N-acyl-2-piperidones undergoes esterification with EtOH at elevated temperature. Single crystal X-ray analysis of an N-acyl-2-piperidone shows amide bond twist, τ = –20.39° and pyramidalization, χN = –11.73°. This weakens the amidic conjugation and might be the factor controlling the reactivity and selectivity of these imides. We envision that the N-acyl-2-piperidone scaffold would be useful in the synthesis of pharmaceuticals and materials.
Design, synthesis and biological evaluation of (E)-3-(3,4,5-trimethoxyphenyl) acrylic acid (TMCA) amide derivatives as anticonvulsant and sedative agents
Zhao, Zefeng,Bai, Yajun,Chen, Xufei,Wu, Shaoping,He, Xirui,Bai, Yujun,Sun, Ying,Zheng, Xiaohui
, p. 2387 - 2396 (2018/09/25)
In this article, a novel series of (E)-3-(3,4,5-trimethoxyphenyl)acrylic acid (TMCA) amide derivatives 1-18 were designed and synthesized by a facile and one-pot step, which were achieved with good yields using 1-hydroxybenzotriazole (HOBT) and 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) as activation system. All the synthesized derivatives were biologically evaluated for their anticonvulsant, sedative activity and neurotoxicity using the maximal electroshock (MES) model, sc-pentylenetetrazol (PTZ) model, pentobarbital sodium-induced sleeping model, and locomotor activity tests, respectively. Among them, compounds 4, 9 and 16 exhibited good anticonvulsant activity in primary evaluation. Furthermore, compound 4 is the most effective anticonvulsant and sedative agent in subsequent tests, while the low threshold of toxicity of compound 4 is vigilant. Compounds 9 and 16 also performed significantly anticonvulsant activity in subsequent tests with weak toxicity. The molecular modeling experiments also predicted good binding interactions of the obtained active molecules with the GABA transferas. Therefore, it could be concluded that the synthesized derivatives 4, 9 and 16 would represent useful lead compounds for further investigation in the development of anticonvulsant and sedative agents.
Fragmentation pattern of amides by EI and HRESI: Study of protonation sites using DFT-3LYP data
Fokoue,Marques,Correia,Yamaguchi,Qu,Aires-De-Sousa,Scotti,Lopes,Kato
, p. 21407 - 21413 (2018/06/26)
Amides are important natural products which occur in a few plant families. Piplartine and piperine, major amides in Piper tuberculatum and P. nigrum, respectively, have shown a typical N-CO cleavage when analyzed by EI-MS or HRESI-MS. In this study several synthetic analogs of piplartine and piperine were subjected to both types of mass spectrometric analysis in order to identify structural features influencing fragmentation. Most of the amides showed an intense signal of the protonated molecule [M + H]+ when subjected to both HRESI-MS and EI-MS conditions, with a common outcome being the cleavage of the amide bond (N-CO). This results in the loss of the neutral amine or lactam and the formation of aryl acylium cations. The mechanism of N-CO bond cleavage persists in α,β-unsaturated amides because of the stability caused by extended conjugation. Computational methods determined that the protonation of the piperamides and their derivatives takes place preferentially at the amide nitrogen supporting the dominant the N-CO bond cleavage.
Design and synthesis of cenocladamide analogues and their evaluation against breast cancer cell lines
Santos, Carla C. F.,Paradela, Luciana S.,Novaes, Luiz F. T.,Dias, Sandra M. G.,Pastre, Julio C.
, p. 755 - 766 (2017/04/27)
This work describes the total synthesis of the alkaloid cenocladamide and a concise library of nine structural analogues aiming at their evaluation against the breast cancer cell line MDA-MB-231. The most promising compound (3; IC50 = 6.6 μM) was also evaluated in a panel of seven breast cancer cell lines and two non-tumorigenic cell lines. We further conducted an initial investigation on the mechanism of action of analogue 3, which lacks the endocyclic double bond when compared to cenocladamide. The present study presents the discovery of a cenocladamide analogue with interesting cytotoxic activity, which could be useful for further optimization towards new chemotherapeutic agents for breast cancer treatment.
Polyethyleneimine-Supported Triphenylphosphine and Its Use as a Highly Loaded Bifunctional Polymeric Reagent in Chromatography-Free One-Pot Wittig Reactions
Xia, Xuanshu,Toy, Patrick H.
supporting information, p. 1737 - 1743 (2015/07/20)
A polyethyleneimine-supported triphenylphosphine reagent has been synthesized and used as a highly loaded bifunctional homogeneous reagent in a range of one-pot Wittig reactions that afforded high yields of the desired products after simple purification procedures. The approach also served efficiently in tandem reaction sequences involving a one-pot Wittig reaction followed by conjugate reduction of the newly formed alkene product in situ. In these transformations, the phosphine oxide groups generated in the Wittig reaction served as the catalyst for activating trichlorosilane in the subsequent reduction reaction.
Synthesis and biological evaluation of new piplartine analogues as potent aldose reductase inhibitors (ARIs)
Rao, Vidadala Ramasubba,Muthenna, Puppala,Shankaraiah, Gundeti,Akileshwari, Chandrasekhar,Babu, Kothapalli Hari,Suresh, Ganji,Babu, Katragadda Suresh,Chandra Kumar, Rotte Sateesh,Prasad, Kothakonda Rajendra,Yadav, Potharaju Ashok,Petrash, J. Mark,Reddy, Geereddy Bhanuprakash,Rao, Janaswamy Madhusudana
, p. 344 - 361 (2013/01/15)
As a continuation of our efforts directed towards the development of anti-diabetic agents from natural sources, piplartine was isolated from Piper chaba, and was found to inhibit recombinant human ALR2 with an IC50 of 160 μM. To improve the efficacy, a series of analogues have been synthesized by modification of the styryl/aromatic and heterocyclic ring functionalities of this natural product lead. All the derivatives were tested for their ALR2 inhibitory activity, and results indicated that adducts 3c, 3e and 2j prepared by the Michael addition of piplartine with indole derivatives displayed potent ARI activity, while the other compounds displayed varying degrees of inhibition. The active compounds were also capable of preventing sorbitol accumulation in human red blood cells.
STEREOSELECTIVE SYNTHESES OF SPICY COMPONENTS IN PEPPERS
Ohta, Akihiro,Tonomura, Yoshiko,Sawaki, Junko,Naohito, Sato,Akiike, Hitomi,et al.
, p. 965 - 973 (2007/10/02)
The syntheses of (E)-α,β-unsaturated amides were accomplished from chloroacetamides and alkyl halides via β-elimination of the pyrazinyl-sulfinyl group, and some of the products are spicy components of piperaceous plants.
