Reactions Of Cyclooctene Research Articles

Dioxomolybdenum(VI) Epoxidation Catalyst Supported on Mesoporous Silica Containing Phosphane Oxide Groups

AbstractA new mesoporous hybrid material (denoted LP‐TEPPPO‐Mo) has been prepared by tethering [MoO2Cl2] onto mesoporous silica previously functionalised with phosphane oxide spacer ligands. The LP‐TEPPPO‐Mo material was tested in the liquid‐phase epoxidation of olefins [cis‐cyclooctene, (R)‐(+)‐limonene, trans‐2‐octene and 1‐octene] with tBuOOH, at 55 °C, and without a co‐solvent, giving at least 90 % selectivity to the corresponding epoxide at 36–77 % conversion: in the case of limonene, regioselectivity favours the epoxidation of the endocyclic double bond, giving mainly 1,2‐epoxy‐p‐menth‐8‐ene. The catalytic system based on a liquid–liquid biphasic system containing the homogeneous complex [MoCl2(O)2{OP(CH2CH3)(Ph)2}2] dissolved in the ionic liquid 1‐butyl‐4‐methylpyridinium tetrafluoroborate leads to lower epoxide selectivity (91 % at 64 % conversion) in the reaction of cyclooctene in comparison to that observed for LP‐TEPPPO‐Mo (100 % at 87 % conversion). The reused solid–liquid and liquid–liquid biphasic catalytic systems show partial loss of catalytic activity.

Effect of bulky substitution on catalytic activity of a manganese salen complex used in biomimetic alkene epoxidation and alkane hydroxylation with sodium periodate

The catalytic activity of Mn(salen)Cl containing tert-pentyl groups at the 3,5-positions of the salen ligand in the epoxidation of alkenes and hydroxylation of alkanes was studied at room temperature, using sodium periodate as an oxygen source. The effects of various axial ligands were investigated in the epoxidation of cyclooctene. Imidazole, as a strong π-donor ligand, was the best axial ligand. The effect of different solvents was studied in the epoxidation of cyclooctene in CH3CN/H2O solvent mixture. The epoxidation reactions of cyclooctene by different oxygen donors including NaIO4, Bu4NIO4, KHSO5, H2O2, H2O2/urea, NaOCl and tert-BuOOH were also studied and NaIO4 was selected as oxygen source. The presence of bulky substituents in the 3,5-positions of the salen ligand was found to increase the catalytic activity of this complex.

Reversible Inhibition/Activation of Olefin Metathesis: A Kinetic Investigation of ROMP and RCM Reactions with Grubbs' Catalyst

The metathesis activity of Grubbs' catalyst 1 was investigated in the presence of N-donor ligands (1-methylimidazole [MIM], 4-(N,N-dimethylamino)pyridine [DMAP], pyridine, and 1-octylimidazole [OIM]). Ring opening metathesis polymerization (ROMP) reactions of cyclooctene (COE), bulk-ROMP reactions of COE and norbornadiene (NBD), and ring closing metathesis (RCM) reactions of diethyl diallylmalonate (DEDAM) were conducted containing various equivalents of N-donor with respect to catalyst. ROMP reactions could be stopped using MIM (1-5 equiv) and DMAP (2-5 equiv), and slowed with pyridine (1-5 equiv) by factors >100, in benzene solution for 24 h. The stopped reactions could be initiated with excess phosphoric acid (H3PO4), and the reactions proceeded faster than with uninhibited Grubbs' catalyst in the first 4 min after reactivation. Thereafter, the reaction proceeded at the same rate as the reaction with the uninhibited catalyst. ROMP reactions in neat COE and NBD could be inhibited for 72 h using 2 equiv of MIM, DMAP, or OIM and activated with H3PO4 to give polymer gels within minutes or less. RCM reactions could be completely inhibited with MIM (1-5 equiv), but upon treatment with H3PO4, the reaction would proceed at a fraction of the initial rate accomplished by uninhibited Grubbs' catalyst 1. A structural investigation of the inhibited species showed that MIM and DMAP completely or partially transform catalyst 1 into the hexacoordinate species 5a or 5b producing free PCy3, which additionally acts as an inhibitor for the ROMP reaction. Upon reactivation, the PCy3 is protonated along the N-donor ligand; however, over the period of 5 min, the phosphine has been found to coordinate back to the ruthenium catalyst. Therefore, the reaction slows to the same polymerization rate as the reaction using the uninhibited catalyst at this point. Complexes 5a and 5b were isolated, characterized, and employed in ROMP and RCM experiments where they exhibited very low catalytic activity.

Preparation of diastereomerically pure 9-carboxybicyclo[6.1.0]nonane derivatives

Reactions of cyclooctene (1) with dibromocyanoacetic esters and copper(I) bromide give (8–10) : 1 mixtures of isomers (2, 3), not stereochemically pure compounds as reported by others. The stereochemistry is elucidated by independent synthesis of one diastereomer (3a). Carbenoid addition of alkoxycarbonylmethylene to 1 and 1,5-cyclooctadiene leads also to exo/endo adduct mixtures. Methods are developed to generate diastereomerically pure compounds (exo-7a, exo-8, endo-9, exo-10, endo-10) from these. Endo esters of this series undergo very facile base catalyzed epimerization.

ChemInform Abstract: THE PRINS REACTION OF CYCLOOCTENE AND CYCLODODECENE

Chemischer InformationsdienstVolume 4, Issue 44 Preparative Organic Chemistry ChemInform Abstract: THE PRINS REACTION OF CYCLOOCTENE AND CYCLODODECENE AKIRA UCHIDA, AKIRA UCHIDASearch for more papers by this authorTOYOHIRO MAEDA, TOYOHIRO MAEDASearch for more papers by this authorSUMIO MATSUDA, SUMIO MATSUDASearch for more papers by this author AKIRA UCHIDA, AKIRA UCHIDASearch for more papers by this authorTOYOHIRO MAEDA, TOYOHIRO MAEDASearch for more papers by this authorSUMIO MATSUDA, SUMIO MATSUDASearch for more papers by this author First published: October 30, 1973 https://doi.org/10.1002/chin.197344152Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume4, Issue44October 30, 1973 RelatedInformation

Reactions of 2-Chlorocycloalkanone Oximes. I. Their Preparations and Conversion to 2-Alkoxy-, 2-Acyloxy- and 2-Alkylthiocycloalkanone Oximes

Abstract The preparation of 2-chlorocycloalkanone oximes has been investigated in detail. 2-Chlorocyclooctanone oxime is prepared in an excellent yield by the reaction of cyclooctene with nitrosyl chloride under the irradiation of light from a high-pressure mercury lamp. 2-Chlorocyclododecadienone oxime, 2-chlorocyclohexanone oxime and 3-chloronorcamphor oxime are prepared in good yields by the addition of nitrosyl chloride to cis, trans, trans-1, 5, 9-cyclododecatriene, cyclohexene and norbornene respectively in the presence of hydrochloric acid. Their displacement reactions with such nucleophilic reagents as sodium alkoxides, sodium ethanethiolate and sodium salts of carboxylicacids have been studied, and the syntheses of 2-alkoxy-, 2-ethylthio- and 2-acyloxy-cycloalkanone oximes have been successfully achieved.