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1.
In this paper, a fully regiocontrolled synthesis of either 2- and 3-substituted benzo[b]furans is described. Direct reaction between phenols and α-bromoacetophenones in the presence of neutral alumina yields 2-substituted benzo[b]furans with complete regiocontrol. When a basic salt such as potassium carbonate is used, the corresponding 2-oxoether is obtained. Cyclization of these latter compounds promoted by neutral alumina yields the corresponding 3-substituted benzo[b]furans. Using the former method, Moracin M and other analogues can be obtained from commercial sources in two preparative steps. DFT calculations provide reasonable reaction paths to understand the formation of 2-substituted benzo[b]furans. 相似文献
2.
Ando K Kawamura Y Akai Y Kunitomo J Yokomizo T Yamashita M Ohta S Ohishi T Ohishi Y 《Organic & biomolecular chemistry》2008,6(2):296-307
Several 2-alkylcarbamoyl-1-alkylvinylbenzo[b]furans were designed to find a selective leukotriene B4 (LTB4) receptor antagonist. 2-(2-Alkylcarbamoyl-1-alkylvinyl)benzo[b]furans having a substituent group at the 3-position, 4-(2-alkylcarbamoyl-1-methylvinyl)benzo[b]furans having a substituent group at the 3-position, and 7-(2-alkylcarbamoyl-1-methylvinyl)benzo[b]furans and 3-(2-alkylcarbamoyl-1-alkylvinyl)benzo[b]furans were prepared and evaluated for LTB4 receptor (BLT1 and BLT2) inhibitory activities. (E)-3-Amino-4-[2-[2-(3,4-dimethoxyphenyl)ethylcarbamoyl]-1-methylvinyl]benzo[b]furan ((E)-17c) showed potent and selective inhibitory activity for BLT2. On the other hand, (E)-7-(2-diethylcarbamoyl-1-methylvinyl)benzo[b]furan ((E)-27a) showed potent inhibitory activity for both BLT1 and BLT2. 相似文献
3.
Ando K Tsuji E Ando Y Kuwata N Kunitomo J Yamashita M Ohta S Kohno S Ohishi Y 《Organic & biomolecular chemistry》2004,2(4):625-635
Novel 3-acetoacetylaminobenzo[b]furan derivatives having a modified triene system at the 3-position were synthesized starting with 3-aminobenzo[b]furans. The enol isomers, 3-[(3-hydroxybut-2-enonyl)amino]benzo[b]furans (), of the 3-acetoacetylaminobenzo[b]furans were obtained as stable isomers owing to formation of a hydrogen bonding between the enol hydroxyl group and the amidocarbonyl group. The planarity of the C-2 substituent through the C-3 side chain suggested the existence of a modified conjugational triene system in the enol compound. Cysteinyl leukotriene 1 and 2 receptor antagonistic activities for these compounds were evaluated. 2-(4-Cyanobenzoyl or ethoxycarbonyl)-3-[(2-cyano-3-hydroxybut-2-enonyl)amino]benzo[b]furans (, ) were moderately active. 相似文献
4.
Benzo[b]furans were prepared in one pot based on the addition/palladium-catalyzed C-H bond functionalization of phenols with bromoalkynes. The addition reactions of phenols to bromoalkynes generated (Z)-2-bromovinyl phenyl ethers in high yields with excellent regio- and stereoselectivity. The obtained (Z)-2-bromovinyl phenyl ethers subsequently proceeded by intramolecular cyclization to afford 2-substituted benzo[b]furans in good yields through palladium-catalyzed direct C-H bond functionalizations. It is important to note that the transformation of phenols with bromoalkynes into benzo[b]furans could be carried out in one pot with a simple and efficient tandem procedure. 相似文献
5.
[reaction: see text] We report a copper(I)-catalyzed procedure for the synthesis of 2-arylbenzo[b]furans. This protocol can be used to synthesize a variety of 2-arylbenzo[b]furans in good to excellent yields. This method can tolerate a variety of functional groups, does not require the use of expensive additives, and is palladium-free. 相似文献
6.
Russian Journal of Organic Chemistry - New spiro heterocycles, spiro[benzo[h]chromene-4,3′-indoles] and spiro[benzo[f]chromene-1,3′-indoles], have been synthesized in 50–60% yield... 相似文献
7.
Various 3-alkyl-2-nitrobenzo[b]furans were synthesized from common intermediate 2-(2-nitroethyl)phenols via a hypervalent iodine-induced oxidative cyclization, with good to excellent yields. This facile route is able to efficiently functionalize 2-nitrobenzo[b]furans, which are difficult to obtain by classical methods. 相似文献
8.
[reaction: see text] A novel and selective palladium-catalyzed annulation of 2-alkynylphenols method for the synthesis of 2-substituted 3-halobenzo[b]furans is presented. In the presence of PdX(2), CuX(2), and HEt(3)NX, 2-substituted 3-halobenzo[b]furans were selectively obtained as the major products. The mechanism of the reaction was also discussed. 相似文献
9.
A convenient method for the synthesis of 2-bromo-3-aroyl-benzo[b]furans from readily accessible precursors has been developed. The 2-bromo group has been employed as a versatile synthetic handle in both palladium-mediated couplings and direct nucleophilic substitutions to give access to a wide range of 2-substituted-3-aroyl-benzo[b]furans. 相似文献
10.
11.
Cho CH Neuenswander B Lushington GH Larock RC 《Journal of combinatorial chemistry》2008,10(6):941-947
The solution-phase parallel synthesis of a 121-member library of multi-substituted benzo[ b]furans is described. 2,3,5-Trisubstituted benzo[ b]furans have been prepared by the palladium-catalyzed substitution of 3-iodobenzofurans by Suzuki-Miyaura, carbonylative Suzuki, Sonogashira, Heck, and carboalkoxylation chemistry. The 3-iodobenzofurans are readily prepared in good to excellent yields by the palladium/copper-catalyzed cross-coupling of various o-iodoanisoles and terminal alkynes, followed by electrophilic cyclization with ICl. 相似文献
12.
A method has been developed for the synthesis of 3-acetonyl- and 3-phenacylben-zo[b]furans by cyclization of 1-arloxy-2,4-pentanediones and 1-phenyl-4-aryloxy-1,3-butanediones in polyphosphoric acid. Acylation of 3-acetonyl(phenyl-benzo-[b]furans with aliphatic acid anhydrides in the presence of perchloric acid gives the benzo[b]furo[2,3-c]pyrylium perchlorates. The recyclization of the pyrylium salts with ammonia, aqueous alkali, and morpholine has been examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 889–893, July, 1987. 相似文献
13.
Ando K Akai Y Kunitomo J Yokomizo T Nakajima H Takeuchi T Yamashita M Ohta S Ohishi T Ohishi Y 《Organic & biomolecular chemistry》2007,5(4):655-663
A novel seven-membered lactam formation method has been established by intramolecular ring closure reaction of 4-bromo-(E)-3-[(2-alkylvinyl)carbonylamino]benzo[b]furans under Heck coupling conditions. A number of furo[2,3,4-jk][2]benzazepin-4(3H)-ones, tricyclicbenzo[b]furans, have been prepared by this method and evaluated for their leukotriene B(4) (LTB(4)) receptor and poly(ADP-ribose)polymerase-1 (PARP-1) inhibitory activities. 相似文献
14.
Sanz R Castroviejo MP Fernández Y Fañanás FJ 《The Journal of organic chemistry》2005,70(16):6548-6551
Tandem Sonogashira coupling/5-endo-dig cyclization reactions on 2,3-dihalophenols suppose a straightforward entry to 4-halobenzo[b]furans, which can be easily transformed into 4-functionalized benzo[b]furans, that are difficult to synthesize by other procedures. On the other hand, the starting 2,3-dihalophenols are efficiently prepared from commercially available 3-halophenols, via their N,N-diethyl carbamates by selective lithiation at the 2-positions by treatment with s-BuLi/TMEDA or LDA at low temperature and reaction with halogen electrophilic reagents. 相似文献
15.
综述了近十几年来报道的具有良好生物活性的2-芳基苯并呋喃类化合物, 以及这一类化合物结构骨架的构建与合成方法. 相似文献
16.
A single step access to multiply substituted benzo[b]furans and indoles has been developed. 相似文献
17.
V. P. Makovetskii I. B. Dzvinchuk Yu. M. Volovenko A. A. Svishchuk 《Chemistry of Heterocyclic Compounds》1980,16(2):113-115
The corresponding 2-amino-3-(benzimidazol-2-yl)benzo[b]furans were obtained by reaction of 2,3,5-trimethyl-1,4-benzoquinone
with 2-cyanomethylbenzimidazoles. It is shown that new benzo[b]furo[2′,3′∶4,5]pyrimido[1,6-a]benzimidazole polynuclear heterocyclic
systems (bases and quaternary salts) are formed in the reaction of these products with acylating agents.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 164–166, February, 1980. 相似文献
18.
Tsuji E Ando K Kunitomo J Yamashita M Ohta S Kohno S Ohishi Y 《Organic & biomolecular chemistry》2003,1(18):3139-3141
Novel 3-acetoacetylaminobenzo[b]furan derivatives with a modified triene system at the 3-position were prepared through acylation of the 3-aminobenzo[b]furans with 5-methylisoxazole-4-carboxylic acid chloride followed by basic cleavage of the isoxazole ring and several of these compounds showed moderate cysteinyl leukotriene receptor 2 antagonistic activity. 相似文献
19.
[reaction: see text] A more sustainable protocol leading to 2-alkyl- or 2-aryl-substituted benzo[b]furans is reported, involving a copper-TMEDA complex which catalyzes the transformation of readily available ketone derivatives into the corresponding benzofurans in good to excellent yields. The reaction is accomplished using water as the solvent without organic cosolvents, and one example of catalyst reutilization is also presented. 相似文献
20.
The reaction of 2-alkynylanisoles/sulfides with SOCl2 and DMSO was conducted to conveniently furnish the biologically interesting 3-(methylthio)-benzo[b]furans/... 相似文献