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1.
Qing-Dong Wang Jin-Ming Yang Dong Fang Jiangmeng Ren Bu-Bing Zeng 《Tetrahedron letters》2017,58(30):2877-2880
An efficient iodine-catalyzed chemoselective 3-formylation of free (N–H) and N-substituted indoles was achieved by using hexamethylenetetramine (HMTA) in the presence of activated carbon under air atmosphere. This new method could provide 3-formylindoles in moderate to excellent yields with fairly short reaction times. Moreover, this catalytic formylation of indoles procedure can be applied to gram-scale synthesis. 相似文献
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Base free Fe(CO)5 catalyzed one-pot synthesis of E/Z alkyl 3-formyl-3-alkyl/aryl/ferrocenyl-2-propenoates (retinoid esters) was achieved by the photolysis of alcoholic solution of terminal acetylenes and carbon monoxide. 8–10 Mol% of ironpentacarbonyl was used as a catalyst for significant transformations of retinoid esters. During the photolysis, alkynes reduced by the simultaneous double functionalization esterification and formylation and resulted in regioselective E/Z isomers of alkyl 3-formyl-3-alkyl/aryl/ferrocenyl-2-propenoates. The bi-functionalization of acetylene is quite unusual and is not observed frequently. The highest yield of the retinoid esters was achieved with 3° alcohols (96%, for E and Z isomers) while the least yield was observed with 1° alcohols (25%, for E and Z isomers). All retinoid esters are regiospecific and have exceptional biological significance to serve as key structural motifs in drug and pharmaceutical applications. 相似文献
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《Tetrahedron》2014,70(51):9601-9614
3,6-Bis-(2-indolyl)dibenzofurans 1,2, and carbazoles 3–6 underwent a range of electrophilic substitution reactions to produce formyl indoles 7–12, biindolyls 24–28 and 33–34, glyoxylamides 40–42, and amides 48. 相似文献
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A simple and efficient total synthesis of ellipticine was developed via the Suzuki-Miyaura coupling of sterically sensitive 2-hydroxybenzeneboronic acid with a multifunctional aryl halide using Pd(OAc)2 as a catalyst and Cu(OAc)2·H2O as an additive in DMSO/H2O as a key step followed by double N-arylation and cyclization. 相似文献
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Nikita A. Kazin Nadezhda S. Demina Roman A. Irgashev Ekaterina F. Zhilina Gennady L. Rusinov 《Tetrahedron》2019,75(33):4686-4696
The effective approaches for regioselective double formylation and acetylation of 5,12-dialkyl-6,7-diaryl-substituted 5,12-dihydroindolo[3,2-a]carbazoles by their treatment with dichloromethyl methyl ether in the presence of SnCl4 or with acetyl chloride in the presence of AlCl3 to afford the 2,9-diformyl or 2,9-diacetyl derivatives, respectively, were developed. Furthermore, new 2,9-bis(2,2-dicyanovinyl) derivatives were synthesized by the Knoevenagel condensation of diformyl-containing substrates with malononitrile, when new 2,9-bis(quinoxaline-2-yl)- and 2,9-bis(benzo[g]quinoxaline-2-yl) derivatives were formed via microwave-promoted oxidation of diacetyl-containing substrates with SeO2 to the corresponding diglyoxals, followed by the reaction of these intermediates with o-phenylendiamine or 2,3-diaminonaphthalene, respectively. The basic optical and electrochemical properties of some 5,12-dihydroindolo[3,2-a]carbazoles were investigated. 相似文献
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The conventional Gross reaction for the formylation of the tetrapropoxythiacalix[4]arene using TiCl4 affords the 18-(chloromethyl)-28-hydroxy-25,26,27-tripropoxythiacalix[4]arene substituted in the meta-position of the macrocycle. The p-tetraformyl-tetrapropoxythiacalix[4]arene, which is an interesting intermediate to the upper-rims functionalization of thiacalixarenes, was prepared with a very good yield using BuLi and N-formylpiperidine. 相似文献
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The title compound 1 was obtained by the reaction of alcohol 18 and triethyl orthoformate catalyzed by aluminum chloride followed by catalytic hydrogenation in good yield. Similarly, compounds 1 and 3 were obtained by intramolecular cyclization of MOM ether 19 with titanium(IV) chloride in moderate yields and isochromanes 1, 3, 26 and 27 by intramolecular cyclization of ether 20 with titanium(IV) chloride in high yields. The structures of compounds 1-3 were elucidated by analysis of spectroscopic data and chemical reactions. The mechanisms on the formation of 1 and 3 are discussed. 相似文献
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Mariappan Periasamy Neela Kishorebabu K. Natarajan Jayakumar 《Tetrahedron letters》2007,48(11):1955-1958
N,N-Dialkylarylamines react with trimethyl orthoformate and TiCl4 under ambient conditions to give the corresponding formyl derivatives in 75-89% yields, whereas the corresponding arylated products are obtained from benzyl ethers and acetals in 42-78% yields. 相似文献
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G. Byre Gowda T.P. Charanraj C.S. Pradeepa Kumara N. Ramesh S.P. Thomas M.P. Sadashiva H. Junjappa 《Tetrahedron letters》2014
A new general route for the synthesis of novel β-aryl-β-(methylthio)acroleins, a class of stable potential 1,3-dielectrophilic synthons, has been reported. The overall protocol involves treatment of either β-chloroacroleins or their precursor iminium salts (generated in situ from the corresponding active methylene ketones under Vilsmeier–Haack reaction conditions) with S,S-dimethyldithiocarbonates (DDC)/aqueous KOH in either a one-pot or two-step process. The dimethyldithiocarbonate (DDC)/30% aqueous KOH has been shown to be an excellent source of methylthiolate anion. 相似文献