Synthetic Communications

Shruti, ; Dwivedi, Jaya; Kishore, Dharma; Sain, Shalu

doi: 10.1080/00397911.2018.1448090pmid: N/A

In recent years, angular and linear phenoxazines and their derivatives and polymers have attracted much attention due to their great pharmacological and industrial utility. So it becomes imperative to review the work done in this area more frequently. Therefore, various synthetic routes for phenoxazines are reviewed here comprehensively.

Ma, Xinyuan; Mo, Qiong; Chang, Jie; Xie, Kai

doi: 10.1080/00397911.2018.1455872pmid: N/A

This paper mainly studied Pd-catalyzed regioselective chlorination of disubstituted 1,2,3-triazoles directed by the 1,2,3-triazole ring. A series of regioselective chlorinated products were synthesized in 47–86% yields using Pd(OAc)2 as a catalyst and CuCl2 as a chlorinated reagent. This method provides a new mean for the synthesis of 1,2,3-triazole halides which combines the formation of C-X bond with C-H activation.

Sağirli, Akın; Dürüst, Yaşar

doi: 10.1080/00397911.2018.1448934pmid: N/A

Isoxazoline and isoxazolidine series were obtained by the reactions of aromatic aldonitrones and nitrile oxides with N-vinyl caprolactam via regioselective 1,3-dipolar cycloadditions that yield only 5-caprolactam-substituted regioisomers in moderate yields. The cycloaddition reactions were optimized using different conditions. The utilized one for the transformation of nitrile oxides to isoxazoles is triethylamine at room temperature and the best protocol have been found for the transformation of nitrones to N-methyl isoxazolidines is silver acetate in refluxing xylene. The structural identification of target compounds was established by IR, nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS) spectra, and X-ray diffraction analyses.

Teimuri-Mofrad, Reza; Rahimpour, Keshvar; Rezaei, Hannaneh; Valizadeh, Hassan; Aghaiepour, Alireza

doi: 10.1080/00397911.2018.1450883pmid: N/A

In this work, novel ferrocene-based ionic liquids, 1-(ferrocenylbutyl)-4-(3-methylimidazolium) Azide and 1-(ferrocenylbutyl)-4-(3-methylimidazolium) Tetrafluoroborate, were synthesized and utilized in the oxidation esterification reaction of aldehydes in the present of different reagents such as NaN3, (K2CO3 and NCS), (KI and KCN), (I2 and K2CO3), (KMnO4). The results were compared with that of [BMIM][X] (X˭Cl, BF4) under the same conditions. As expected, ferrocene-based ionic liquids showed better results; It seems, iron nuclear may play a similar role such as iron catalysts in these novel ionic liquids and can facilitated the oxidation esterification reaction with improve the yield and decrease the reaction time.

Zhao, Zijian; Lian, Yan; Zhao, Chang; Wang, Bing

doi: 10.1080/00397911.2018.1452262pmid: N/A

A Pd(II)-catalyzed desulfitative arylation protocol between sulfonamides and sodium arylsulfinates was herein reported. The direct arylation reaction was successfully achieved by a Pd(II)/Ag(I)-mediated system without participation of any external ligands with a release of SO2. And different N-aryl sulfonamides were obtained readily in up to 86% yields, exhibiting good functional groups tolerance (25 examples).

Taywade, Amol; Chavan, Snehal; Ulhe, Avinash; Berad, Baliram

doi: 10.1080/00397911.2018.1454474pmid: N/A

Two pyridine-based ligands (N-((pyridin-2-yl) methyl) pyridin-2-amine) L1 and (N-((pyridin-2-yl) methylene) pyridin-2-amine) L2 are explored in present work which are inexpensive, effective and environmentally benign in their properties. These have been utilized for C-N cross coupling reaction resulting in N-arylation. The N-arylation of indole, imidazole and triazole have been successfully carried out with different aryl and heteroaryl halides using these ligands.

Liu, Xiong-Wei; Yao, Zhen; Wang, Guan-Lian; Chen, Zhi-Yong; Liu, Xiong-Li; Tian, Min-Yi; Wei, Qi-Di; Zhou, Ying; Zhang, Jian-Fei

doi: 10.1080/00397911.2018.1454475pmid: N/A

Developed herein is a new methodology for a hybrid of two pharmacophoric oxindole and isoxazole motifs to construct isoxazole-fused 3,3′-disubstituted oxindole scaffolds via an efficient 1,6-addition reaction of 3-substituted oxindoles to 3-methyl-4-nitro-5-alkenylisoxazoles, which might generate novel drug-like molecules for biological screenings. The method gives an easy access to a series of isoxazole-fused 3,3′-disubstituted oxindoles with 26 examples in high yields (up to 92% yield) and good diastereoselectivity (up to >20:1), which makes possible the synthesis of libraries under similar circumstances. Subsequently, a sequential Michael addition/amidation/reductive cyclization process was designed for accessing this hexahydro-1H-pyrido[2,3-b]indol-2-one scaffold, which is a key structural skeleton found in a large number of biologically active natural products and pharmaceutical compounds. Hexahydro-1H-pyrido[2,3-b]indol-2-one scaffold 7cg could be obtained in 42.5% overall yield after 4 steps.

Arya, Kripalaya Ratheesh; Rajendra Prasad, Karnam Jayarampillai

doi: 10.1080/00397911.2018.1455211pmid: N/A

A solvent-free, one-pot, and operationally simple protocol was adopted to synthesize a new series of multifunctionalized pyrido[2,3-a]carbazole derivatives which were structurally characterized by FTIR, 1H-NMR, 13C-NMR, and elemental analysis. The synthesized compounds were screened in vitro for their antibacterial activity and the compounds showed weak to moderate inhibition of bacterial growth. The antioxidant properties of the compounds were evaluated by their 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity and total antioxidant capacity. Moreover, the cytotoxic effect of the compounds was examined on cancerous cell lines MCF-7 and A549 under in vitro conditions and the results showed that the compounds exhibited significant anticancer activity. Furthermore, the morphological changes and apoptosis induction were studied by inverted light microscopy, acridine orange/ethidium bromide, and 4′,6-diamidino-2-phenylindole dihydrochloride fluorescence microscopic analyses. The results indicated that among pyridocarbazole compounds, 2-ethoxy-8-chloro-4-(thiophen-2′-yl)-5,6-dihydro-11H-pyrido[2,3-a]carbazol-3-carboxamide 6g could be exploited as significant antioxidant and anticancer agents.

Obi, Grace; Van Heerden, Fanie R.

doi: 10.1080/00397911.2018.1455212pmid: N/A

An efficient methodology for the synthesis of 6-styrenylpyrone in a four-step sequence is reported. The reactions were performed under catalyst-free conditions with mild and affordable reagents to produce 5,6-dehydrokawain and fluorinated derivatives in good to excellent overall yields (72–86%) on a multigram scale. Two novel difluorinated derivatives are reported here for the first time.

Reddy, Karnekanti Rajender; Sridhar, Gattu; Sharma, Gangavaram V. M.

doi: 10.1080/00397911.2018.1455213pmid: N/A

Synthesis of new β3-amino acid, peptides and conformational analysis are reported from d-ribose, using Wittig olefination and Aza-Michael addition.