Search

A convenient synthetic protocol for diverse fused chromenes was successfully developed by a three-component reaction of alkyl isocyanides, dialkyl but-2-ynedioates, and various cyclic 1,3-dipolarophiles containing o-hydroxyphenyl group. In the absence of any catalyst, the three-component reaction of alkyl isocyanides, dialkyl but-2-ynedioates, and 3-(o-hydroxyarylidene)indolin-2-ones in tetrahydrofuran at 60 °C resulted in unique functionalized spiro[cyclobuta[c]chromene-1,3′-indolines] in good yields and with high diastereoselectivity. However, the similar three-component reaction with 2-(5-halo-2-hydroxyarylidene)indolin-2-ones afforded unexpected chain products in satisfactory yields. In addition, the three-component reaction of alkyl isocyanides, dialkyl but-2-ynedioates, and 2-(o-hydroxyarylidene)-1,3-indanediones in tetrahydrofuran at 60 °C resulted in complex indeno[2′,1′:5,6]pyrano[3,4-c]chromene derivatives in high yields and with high diastereoselectivity.

Abstract: A one-pot multi-component reaction is developed for the efficient synthesis of 4,5-dibenzylidene octahydroacridines in high yields. The reaction is performed by the tandem reaction of three molar equivalent aromatic aldehydes with two molar equivalent 4-alkylcyclohexanone in the system of NH4OAc/HOAc under microwave irradiation. MediaObjects/11532_2008_27_Fig1_HTML.jpg

The domino reactions of 1,3-thiazolidinedione, malononitrile, and aromatic aldehydes in the presence of different organic amines were studied. Secondary amines such as pyrrolidine, piperidine, morpholine, and dimethylamine and primary amines such as benzylamine yield dihydrothiophene derivatives through a domino ring-opening/recyclization reaction of 1,3-thiazolidinedione. Bulky diethylamine, diisopropylamine, and 1,4-diazabicyclo[2.2.2]octane give spirocyclohexano-1,3-thiazole through a double Michael addition/spirocyclization reaction.

Microporous polycarbazole via straightforward carbazole-based oxidative coupling polymerization is reported. The synthesis route exhibits cost-effective advantages, which are essential for scale-up preparation. The Brunauer–Emmett–Teller specific surface area for obtained polymer is up to 2220 m2g–1. Gas (H2and CO2) adsorption isotherms show that its hydrogen storage can reach to 2.80 wt % (1.0 bar and 77 K) and the uptake capacity for carbon dioxide is up to 21.2 wt % (1.0 bar and 273 K), which show a promising potential for clean energy application and environmental field. Furthermore, the high selectivity toward CO2over N2and CH4makes the obtained polymer possess potential application in gas separation.

The BF3OEt2catalyzed one-pot 1,3-dipolar cycloaddition reaction of benzylamines, isatins and dimethyl acetylenedicarboxylate in dry methylene dichloride afforded the functionalized spiro[indoline-3,2′-pyrroles] in moderate to good yields and with high diastereoselectivity.

A series of difunctionalized copillar[5]arene Schiff bases from the condensation of salicylaldehyde and its 5-chloro, 5-bromo, 3,5-di(t-butyl) substituted derivatives with corresponding di-amino-functionalized pillar[5]arenes were successfully prepared. The single crystal structures and coordination properties to some transition metal ions were investigated.

The three-component reaction of triphenylphosphine, dialkyl but-2-ynedioate and arylidene pivaloylacetonitrile in dry methylene dichloride at room temperature resulted in unexpected densely substituted 1-(triphenyl-λ5-phosphanylidene)ethyl)-2,3-dihydrofurans in satisfactory yields with high diastereoselectivity.

A highly efficient Cu-catalyzed 1,4-difunctionalization of isoquinolinium salts was developed with ether and X–(X = Br, Cl) as the halogen source under mild conditions. This transformation involves the combination of oxidative coupling and copper-catalyzed halogen atom-transfer radical processes. This method not only provides an efficient way to prepare various substituted azaarenes but also achieves the selective construction of C(sp2)–X (X = Br, Cl) bonds from a halogen anion and nucleophilic carbon atom via a free-radical process.