The reactions of 1,2-bis(dimethylchlorosilyl)ethane (1), 1,2-bis(dimethylchlorosilyl)ethene (6), and 1,2-bis(dimethylchlorosilyl)ethyne (7) with gem-bis-(hydroperoxides) 2a-h and 1,1'-bis( hydroperoxy)bis-(cycloalkyl)peroxides 4a-c were found to proceed in an unusual way. Thus, the reactions do not give the expected polymeric peroxides; instead, they produce cyclic silicon-containing peroxides containing 2, 4, or 6 silicon atoms in the ring: 9- (3a-h), 12- (5a-c), 18- (8, 12), 24- (9, 10), 27- (13), and 36-membered (11) compounds. The size of the rings produced in the reactions increases in the series 1,2-bis(dimethylchlorosilyl)ethane < 1,2-bis(dimethylchlorosilyl)ethene < 1,2-bis(dimethylchlorosilyl)ethyne. The resulting 9- and 12-membered cyclic peroxides are stable under ambient conditions. These compounds were isolated by chromatography and characterized by H-1, C-13, and Si-29 NMR spectroscopy, X-ray diffraction, elemental analysis, and high-resolution mass spectrometry. The yields vary from 77 to 95%. Structures of the larger-size rings (18-, 24-, 27-, and 36-membered peroxides) were confirmed by H-1, C-13, and Si-29 NMR spectroscopy using 2D (COSY, HSQC, and HMBC), 2D DOSY H-1, 3D H-1-Si-29 HMBC-DOSY NMR experiments, and elemental analysis.
The electrochemical synthesis of 3,12-dimethyl-7,8,15,16-tetraoxadispiro[5.2.5.2]hexadecane (1,2,4,5-tetraoxane) from 1,1-bis-hydroperoxy-4-methylcyclohexane on platinum electrode in a cell with separated and unseparated cathode and anode space in an aprotic solvent is conducted. The kinetics of electrochemical oxidation of 1,1-bis(hydroperoxy)-4-methylcyclohexane is studied. The current yield of the reaction is determined.
The methods of synthesis and reactions of organosilicon and organogermanium peroxides are surveyed. The emphasis is placed on the studies reported in the last two decades, because in this period, the use of singlet oxygen and the Isayama–Mukaiyama reaction for the synthesis of organosilicon peroxides started. The use of these compounds in the development of antiparasitic agents is considered. The bibliography includes 220 references.
The possibility is shown of electrochemical synthesis of 3,12-dimethyl-7,8,15,16-tetraoxadispiro[5.2.5.2]hexadecane that belong to the class of 1,2,4,5-tetraoxanes by oxidation of 1,1-dihydroperoxy-4-methylcyclohexane using a Pt anode.
The reaction of enol ethers with the I-2-H2O2 system in diethyl ether affords 2-iodo ketones and the previously unknown 2-iodo-1-methoxy hydroperoxides. In the presence of the I-2-H2O2 system, the latter compounds undergo deperoxidation and demethoxylation to form 2-iodo ketones. The reaction conditions were found for the synthesis of 2-iodo ketones from enol ethers in 67-94% yields.
First, previously unknown, cyclic organogermanium peroxides, 1,2,4,5,7,8-hexaoxa-3-germonanes, were synthesized by the reaction of 1,1'-dihydroperoxydi(cyclododecyl) peroxide with (di)alkyl(aryl)dihalogengermanes. The new compounds have a higher tendency to undergo hydrolysis compared to silicon-containing analogs. (C) 2009 Elsevier B.V. All rights reserved.
Iodine-catalyzed reactions of bis(1-hydroperoxycycloalkyl) peroxides with ketals give, via replacement of two alkoxy groups, the cyclic peroxides, 1,2,4,5,7,8-hexaoxonanes, in up to 82% yields. The cyclization is very sensitive to the solvent nature. Among MeCN, Et2O, THF, CHCl3, CH2Cl2, hexane, and MeOH, the best results were achieved with the first three solvents.
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The reducing agents Ph(3)P, (C(8)H(17))(3)P, or NH(2)C(S)NH(2) promote the ring contraction of nine-membered triperoxides, viz., 1,2,4,5,7,8-hexaoxa-3-silonanes, giving rise to seven-membered rings belonging to the previously unknown class of monoperoxides, viz., 1,3,5,6-tetraoxa-2-silepanes, in yields from 67% to 91%. Therefore, the selective reduction of the SiOOC fragments to SiOC in molecules containing simultaneously the COOC fragment was performed for the first time.
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
A method was developed for the synthesis of the previously unknown class of organic peroxides, 1,2,4,5,7,8-hexaoxa-3-silonanes, based on the reaction of dialkyldichlorosilanes with 1,1'-dihydroperoxyperoxides. 1,2,4,5,7,8-Hexaoxa-3-silonanes are rather stable under ambient conditions and were characterized by NMR spectroscopy, X-ray diffraction, and elemental analysis. Their yields are in a range of 59-96%. The attempts were made to prepare 1,2,4,5-tetraoxa-3-silinanes by the reaction of dialkyldichlorosilanes with gem-bishydroperoxides. 1,2,4,5-Tetraoxa-3-silinanes were detected by NMR spectroscopy; these compounds rapidly decompose upon isolation.
It was found that iodine-catalyzed reactions of geminal bishydroperoxides with acetals proceed with the replacement of only one alkoxy group by the peroxide group to give previously unknown structures of 1-hydroperoxy-1'-alkoxyperoxides in yields up to 64%. The same compounds are formed in the iodine-catalyzed reactions of geminal bishydroperoxides with enol ethers. The nature of the solvent has a decisive influence on the formation of 1-hydroperoxy-1'-alkoxyperoxides. In the series of Et(2)O, THF, EtOH, CHCl(3), CH(3)CN, and hexane, the best results were obtained with the use of Et(2)O or THF as the solvent.
The acid-catalyzed oxidation of cycloalkanones C5–C8 and C12 with hydrogen peroxide in alcohols was performed, and dicarboxylic acid esters were obtained as the major products in 53–70% yields. In the first step, geminal bishydroperoxides are generated from five-to-seven-membered cyclic ketones. The Baeyer–Villiger reaction is a side process accompanied by the formation of ω-hydroxycarboxylic acid esters.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
A convenient procedure was developed for the synthesis of geminal bishydroperoxides by the sulfuric acid-catalyzed reaction of ketones with hydrogen peroxide in THF. Gem-bishydroperox ides were prepared by the reactions of five- to seven-membered cycloalkanones without additional purification in 80-95% yields with a purity of more than 95%; their acyclic analogs were prepared in 43-72% yields.
A new versatile procedure was developed for the synthesis of 1,2,4,5,7,8-hexaoxonanes based on the Lewis acid catalyzed reaction of acetals with 1,1'-dihydroperoxydicycloalkyl peroxides. The procedure substantially extends the structural diversity of these compounds and, in most cases, allows the synthesis of these compounds in higher yields (to 96%) and with higher selectivity. Complexation of hexaoxonane with chloroform was documented for the first time. The structures of several triperoxides were established by X-ray diffraction.
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