摘要:

AbstractThe oxidation of a series of ketene‐S,S‐acetals,2a–f, and a series of thioacetals and thioketals,4a–g, with a fourfold or greater excess of dimethyldioxirane,1, produced the corresponding bis‐sulfones3a–fand5a–gin excellent yields. The reaction of the bis‐sulfides with one, two, and three equivalents of1yielded monosulfoxides, bis‐sulfoxides, and sulfoxide‐sulfones, respectively, as the major products. The order of addition of the reactants as well as the temperature of the reaction mixture changed the product distributions. The use of low‐temperature, rapid stirring and the addition of the dioxirane solution to the bis‐sulfide maximized the yield of the major product. The results are consistent with an electrophilic oxygen‐atom transfer mechanism in which the rate of sulfide oxidation is much faster than oxidation of sulfoxide to sulfone. However, sulfoxide oxidation is of a sufficient rate such that local concentration e

ISSN:1042-7163    

DOI:10.1002/hc.520050522

出版商:VCH Publishers, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe title reaction is highly regioselective, leading in both cases to 4,5,6,7,8,9‐hexafluoronaphtho[1,2‐c]‐[1,2,5]thiadiazole (whose struture is confirmed by X‐ray structure analysis) and 4,5,6,7,8,9‐hexafluoronaphtho[2,3‐c][1,2,5]thiadiazole in ∼94 : 6 ratio. The preferred direction of cyclization is consistent with final product thermodynamics as well as factors of kinetic control for orbital‐controlled reactions (calculated by use of front

ISSN:1042-7163    

DOI:10.1002/hc.520050523

出版商:VCH Publishers, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractNew and efficient one pot syntheses of 2‐thioureidobenzimidazole (V), 2‐thioureidobenzoxazole (VI), and 2‐thioureidobenzothiazole (VII) have been developed. The target compounds were obtained in good yields by condensing the title synthon commonly known as isoperthiocyanic acid (I) with 1,2‐diaminobenzene (II), 2‐aminophenol (III), and 2‐aminothiophenol (IV), respectively, in various organic solvent and in the

ISSN:1042-7163    

DOI:10.1002/hc.520050524

出版商:VCH Publishers, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractIndole‐2,3‐dione was treated with malonic acid in a mixture of ethanol/pyridine to afford 1‐[3‐(2‐oxoindolinylidene)]acetic acid (3), which was then reacted with thionyl chloride to give the corresponding acid chloride (4). The acid chloride4reacted with arenes in the presence of AlCl3to yield substituted 3‐(2‐oxoindolinylidene)acetophenones5a–c. Compounds5a–cwere alkylated with methyl iodide to afford6a–c. Compounds6a–cwere treated with hydrazine derivatives, hydroxylamine hydrochloride, urea, and thiourea to yield the complex spiro compounds7a–i,8a

ISSN:1042-7163    

DOI:10.1002/hc.520050525

出版商:VCH Publishers, Inc.    

年代:1994

数据来源: WILEY

ISSN:1042-7163    

DOI:10.1002/hc.520050501

出版商:VCH Publishers, Inc.    

年代:1994

数据来源: WILEY