Guolan Dou

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A series of novel spiropyrrolidines and spirothiapyrrolizidines were synthesized via a three-component 1,3-dipolar cycloaddition reaction of isatin or acenaphthenequinone, sarcosine or thiaproline and 4-hydroxy-6-methyl-3-((E)-3-phenylacryloyl)-2H-pyran-2-ones in refluxing ethanol. Advantages of this method include the availability of starting materials,(More)
A convenient and efficient method for the synthesis of novel dispiropyrrolidine bisoxindole derivatives by 1,3-dipolar cycloaddition reaction of azomethine ylides has been developed. The synthesis was achieved by using a one-pot multicomponent procedure. The features of this procedure were characterized by the following: mild reaction conditions, high(More)
A series of new naphtho[1,2-e][1,3]oxazine derivatives such as trans-1,3-diaryl-1H-naphtho[1,2-e][1,3]oxazine-2(3H)-carbonyl chloride, 1-aryl-2-benzyl-1,2- dihydronaphtho[1,2-e][1,3]oxazine-3-one, and trans-1,3-diaryl-1H-naphtho[1,2-e] [1,3]oxazine-2(3H)-carbaldehyde were selectively synthesized via a chemoselective reaction of(More)
1,2,3,5-Tetrasubstituted and 1,2,3,4,5-pentasubstituted pyrroles may be synthesized through three-component reaction of 1,3-diketones, aldehydes, and amines induced by low-valent titanium reagent. High regioselectivity was achieved. Compared with the classical synthetic method, this new method has the advantages of short reaction time (15 min), high yields,(More)
A mild, efficient, one-pot protocol for the synthesis of indazole-3(2H)-ones via cyclization of nitro-aryl substrates through low-valent titanium reagent has been described. The method used Triethylamine (TEA) to control pH. Particularly, 2-aminobenzonitriles were synthesized by one step easily. The mechanistic course of the reaction suggests the(More)
An efficient and convenient method for the preparation of cis-bispyrimidodiazepinone derivatives has been described. A variety of substrates can participate in the process with good yields, making this methodology suitable for library synthesis in drug discovery efforts. The mechanistic course of the reaction suggests the involvement of reduction, coupling(More)
The synthesis of a series of biquinazoline-2,2'-diones starting from o-nitrobenzaldehydes, anilines, and triphosgene is presented. This general approach features a novel and easy way for access to the target products. The mechanistic course of the reaction suggests the involvement of reduction, coupling, and cyclization by one-pot. These compounds were also(More)
An efficient, convenient, one-pot synthesis of 2,3,3a,4-tetrahydropyrrolo[1,2-a]quinazolin-5(1H)-one and 2,3,3a,4-tetrahydropyrrolo[1,2-a]quinazoline-1,5-dione was accomplished in good yields via the novel reductive cyclization of 2-nitrobenzamides with haloketones or keto acids mediated by SnCl(2).2H(2)O system. A variety of substrates can participate in(More)
The synthesis of a series of quinazolinone derivatives such as 2-thioxoquinazolinones, imidazo[1,2-c]quinazolin-5-amines, and benzimidazo[1,2-c]quinazolin-5-amines, starting from nitro-compounds has been described. This general approach features a easy way for access to the target quinazolinone derivatives. The key cyclization step embraces the formation of(More)
A mild and efficient synthesis of pyrazolo[3,4-b]pyridine-6(7H)-one derivatives via a three-component reaction of an aldehyde, Meldrum's acid and 3-methyl-1H-pyrazol-5-amine using recyclable polyethylene glycol (PEG)-400 as a reaction medium is described. This method has the advantages of accessible starting materials, good yields, mild reaction conditions(More)