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The cycloalkanones (1a-lf) have been converted into their corresponding cycloalkane carboxylates (2a-2f) by a lead (IV) acetate promoted rearrangement in presence of perchloric acid in triethyl orthoformate. 相似文献
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Hormi MecadonMd. Rumum Rohman Iadeishisha KharbangarBadaker M. Laloo Icydora KharkongorMantu Rajbangshi Bekington Myrboh 《Tetrahedron letters》2011,52(25):3228-3231
An efficient four-component synthesis of 6-amino-4-alkyl/aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles involving ethyl acetoacetate, hydrazine hydrate, malononitrile, and various aldehydes using l-proline (10 mol %) in water under mild reaction condition in excellent yields is established. A comparative study of l-proline with γ-alumina, basic alumina, and KF-alumina was also carried out. The generality and functional tolerance of this convergent and environmentally benign method is demonstrated. 相似文献
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Laloo BM Mecadon H Rohman MR Kharbangar I Kharkongor I Rajbangshi M Nongkhlaw R Myrboh B 《The Journal of organic chemistry》2012,77(1):707-712
An efficient regioselective protocol for the C-C bond formation by the unexpected α,α-diarylation of aromatic ketones with unactivated arenes in the presence of selenium dioxide and boron trifluoride etherate has been developed. The generality and functional tolerance of this protocol is demonstrated by the synthesis of a series of triarylethanones. 相似文献
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Md. Rumum RohmanHormi Mecadon Abu T. KhanBekington Myrboh 《Tetrahedron letters》2012,53(39):5261-5264
The γ-alumina catalyzed synthesis of a new series of β-functionalized 5-methyl-1H-pyrazol-3-ol derivatives by the multi-component reaction of an aldehyde, ethylcyano acetate, and in situ generated 3-methyl-1H-pyrazol-5(4H)-one obtained from hydrazine monohyrade and ethyl acetoacetate in aqueous medium is described. The present reaction forms an important variant of the Yonemitsu-type multi-component reaction. The salient features of this present environmentally benign method are: recyclability of the catalysts, mild reaction condition, excellent yields of product, and the use of aqueous medium in the reaction. 相似文献
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Triethylbenzylammonium Chloride as a Useful and Efficient Catalyst for the Alkylation of Indole/substituted Indoles in Water: A Comparative Study between Conventional and Microwave Irradiation 下载免费PDF全文
Shokip Tumtina Chingrishon Kathing Ivulho Tovishe Phucho Ridaphun Nongrum Bekington Myrboh Rishanlang Nongkhlaw 《中国化学会会志》2015,62(4):321-327
A green and facile method for the alkylation of indole/substituted indole in water using a phase Transfer catalyst (Triethylbenzylammonium Chloride, TEBA) to synthesise bis‐indolyl methanes (BIMs) and Michael addition of indole to α,β‐unsaturated carbonyl compounds is reported. The substitution of indoles occurred exclusively at the 3‐position and products of N‐alkylation has not been observed. However, for 3‐substituted indoles, reactions were found to occur at the 2‐position. A comparative study between conventional heating and microwave irradiation has also been reported. 相似文献
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Deboshikha Bhattacharjee Dipankar Sutradhar Asit K. Chandra Bekington Myrboh 《Tetrahedron》2017,73(25):3497-3504
The multi-component reactions involving aromatic aldehydes, dimethylcyclohexane-1, 3-dione/cyclohexane-1, 3-dione and barbituric acids were carried out in presence of the organo catalyst l-proline in aqueous medium at ambient temperature. The reactions afforded chromeno[2,3-d]pyrimidinones in excellent yields and with high enantioselectivities. The above reactions exhibited the efficient asymmetric induction property of the organo catalyst l-proline as reported earlier. In the absence of barbituric acid the method proved equally efficient when aromatic aldehydes readily condensed with 2 mol of cyclohexane-1, 3-dione in presence of l-proline to give Xanthenes derivatives in good yields. The protocol reported here is benign to the environment as water is used as the solvent and purification does not involve any chromatographic procedures. Selected compounds were further studied using DFT calculations in order to establish a clear picture about the geometric parameters and the electronic absorption spectra of the compounds. 相似文献
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Hormi MecadonMd. Rumum Rohman Mantu RajbangshiBekington Myrboh 《Tetrahedron letters》2011,52(19):2523-2525
γ-Alumina as an expedient and recyclable catalyst for the synthesis of 6-amino-4-alkyl/aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles in water via a four-component reaction is established. Comparative study of the efficacy of γ-alumina, basic alumina and KF-alumina is also discussed. The method presented is mild, environment friendly, inexpensive and functionality tolerable to give the products in good to excellent yields. 相似文献
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Pushpak Mizar Mecadon Hormi Mantu Rajbangshi Bekington Myrboh 《Journal of heterocyclic chemistry》2011,48(5):1187-1191
A simple and efficient method for the synthesis of highly substituted benzo‐ and hetero‐fused analog of 2, 3‐dihydro‐6H‐oxa‐3a‐aza‐phenalene was developed using 2H‐1, 4‐benzoxazine and α‐oxoketene dithio‐acetals. J. Heterocyclic Chem., (2011). 相似文献