2565-83-5Relevant academic research and scientific papers
Synergic actions of BEA-type zeolites and ultrasonic irradiation in conversion of geraniol
Ramishvili, Ts.,Tsitsishvili,Ivanova,Kokiashvili,Bukia,Kurtsikidze
, p. 438 - 444 (2019)
The geraniol conversion reaction was initiated by the simultaneous action of micro- and micro-mesoporous BEA-type zeolites and ultrasonic irradiation (UMR-300B hybrid reactor, 25 kHz, 100-900 W; SRF-1, 20-60 kHz, 100 W). Geraniol by ultrasonic irradiation at 27-100 °C, had a low degree of conversion, upto 2 %. Geraniol was a resistant to ultrasound in argon atmosphere solutions of N,Ndimethylformamide and methanol. In methanolic solution, geraniol was actively converted to linalool and to methyl ethers of linalool and nerol with the selectivity of 80 % on zeolite BEA-25 under ultrasonic irradiation in air at 30 °C. Using BEA-type zeolite/ultrasonicassisted reaction was increased the degree of conversion of geraniol, the selectivity and yield to linalool and nerol on the most active RBEA-25 zeolite by prolonged ultrasonic irradiation (1.5-5 h) or under combined ultrasound and microwave irradiation (US 300 W/MW 550 W, 1.5 h, 80 °C).
Organometallic derivatives of natural products: Dicobalt hexacarbonyl complexes of geranyl-alkynes
Moore, Angela,Ostermann, Johannes,Ortin, Yannick,McGlinchey, Michael J.
, p. 7881 - 7888 (2016/09/12)
Treatment of methyl geranyl ether with diiron nonacarbonyl leads to hydrogen migration to form previously unknown E and Z 1-methoxy-3,7-dimethyl-1,6-octadiene in low yield. Sodium propargyl alkoxide and geranyl bromide yield propargyl geranyl ether, 13; subsequent reaction with dicobalt octacarbonyl and then bis(diphenylphosphino)methane furnishes the corresponding alkyne-Co2(CO)4(dppm) tetrahedral cluster, 16. Reaction of geranylacetone with phenylethynyl-lithium, and then with Co2(CO)8, forms (1-phenyl-3,7,11-trimethyldodeca-6,10-dien-1-yn-3-ol)Co2(CO)6, 19. The carbynyltricobaltnonacarbonyl clusters RC(O)CCo3(CO)9, where R = geranyl, 23, or farnesyl, 25, are preparable in very good yield either by reaction of the appropriate alcohol with trichloroacetyl chloride and then Co2(CO)8, or by reaction with the metal-stabilized acylium ion [Co3(CO)9CCO]+, 24. Potential use of these (η2-alkyne)dicobalt complexes in Pauson-Khand or Nicholas cyclizations is discussed.
Bis(phosphine)cobalt dialkyl complexes for directed catalytic alkene hydrogenation
Friedfeld, Max R.,Margulieux, Grant W.,Schaefer, Brian A.,Chirik, Paul J.
supporting information, p. 13178 - 13181 (2015/03/30)
Planar, low-spin cobalt(II) dialkyl complexes bearing bidentate phosphine ligands, (P - P)Co-(CH2SiMe3)2, are active for the hydrogenation of geminal and 1,2-disubstituted alkenes. Hydrogenation of more hindered internal and endocyclic trisubstituted alkenes was achieved through hydroxyl group activation, an approach that also enables directed hydrogenations to yield contrasteric isomers of cyclic alkanes.
Hydroxy-group effect on the regioselectivity in a photochemical oxetane formation reaction (the Paterno-Buechi Reaction) of geraniol derivatives
Hisamoto, Ken,Hiraga, Yoshikazu,Abe, Manabu
experimental part, p. 1469 - 1473 (2012/06/18)
The Paterno-Buechi (PB) reaction of geraniol derivatives 1, which contain allylic alcohol functionality and unfunctionalized double bonds, with benzophenone was investigated to see the effect of the hydroxyl group on the regioselectivity of the oxetane formation, i.e., 2/3. At low concentration of geraniol (1a), oxetanes 2a and 3a were formed in a ratio of 2a/3a = ca. 50/50. The oxetane 2a is derived from the PB reaction at the allylic alcohol moiety, whereas the PB reaction at the unfunctionalized double bond produces the oxetane 3a. The PB reaction of the hydroxy-protected methyl ether 1b and acetate 1c gave selectively oxetanes 3b,c derived from the reaction at the more nucleophilic double bond, 2/3 ～ 15/85. The hydroxyl-group effect was found to be small, but apparently increased the formation of 2a in the PB reaction with geraniol (1a). The Royal Society of Chemistry and Owner Societies.
Allylic and allenic halide synthesis via NbCl5- and NbBr 5-mediated alkoxide rearrangements
Ravikumar,Yao, Lihua,Fleming, Fraser F.
supporting information; experimental part, p. 7294 - 7299 (2010/01/16)
(Chemical Equation Presented) Addition of NbCl5 or NbBr 5 to a series of magnesium, lithium, or potassium allylic or propargylic alkoxides directly provides allylic or allenic halides. Halogenation formally occurs through a metallahalo-[3,3] rearrangement, although concerted, ionic, and direct displacement mechanisms appear to operate competitively. Transposition of the olefin is equally effective for allylic alkoxides prepared by nucleophilic addition, deprotonation, or reduction. Experimentally, the niobium pentahalide halogenations are rapid, afford essentially pure (E)-allylic or -allenic halides after extraction, and are applicable to a range of aliphatic and aromatic alcohols, aldehydes, and ketones. 2009 American Chemical Society.
Iodine catalyzed selective O-alkylation of alcohols with orthoesters
Kumar,Anjaneyulu,Joyasawal, Sipak,Pawan Chakravarthy,Naveen Kumar,Yadav
, p. 189 - 192 (2008/02/13)
In the present communication O-alkylation of a number of allylic and benzylic alcohols has been described.
Reaction of orthoesters with alcohols in the presence of acidic catalysts: A study
Sampath Kumar,Joyasawal, Sipak,Reddy,Pawan Chakravarthy,Krishna,Yadav
, p. 1686 - 1692 (2007/10/03)
Allylic and benzylic alcohols are converted into corresponding unsymmetrical ethers when reacted with various orthoesters in the presence of montmorillonite KSF at ambient temperature. A detailed study has been undertaken to examine the mechanism and generality of these reactions with regard to various acidic catalysts, which reveal interesting competitive reactions mainly O-acetylation, together with trace amount of dimerized product. The type of the side product and their relative quantity depends upon the nature of the catalyst employed. Furthermore, the low yields of the Claisen rearrangement product obtained from allylic alcohols under heating is rationalized due to the formation of some of these products.
A MILD PROCEDURE FOR ETHERIFICATION OF ALCOHOLS WITH PRIMARY ALKYL HALIDES IN THE PRESENCE OF SILVER TRIFLATE
Burk, Robert M.,Gac, Todd S.,Roof, Michael B.
, p. 8111 - 8112 (2007/10/02)
Alcohols were alkylated in good to excellent yield with primary alkyl halides by a method employing silver triflate and a non-nucleophilic amine base.
TRIMETHYLSILYLDIAZOMETHANE: A CONVENIENT REAGENT FOR THE O-METHYLATION OF ALCOHOLS
Aoyama, Toyohiko,Shioiri, Takayuki
, p. 5507 - 5508 (2007/10/02)
Trimethylsilyldiazomethane smoothly reacts with alcohols in dichloromethane in the presence of 42percent aqueous fluoroboric acid to give methyl ethers in good to high yields.
Methylation of Alcohols and Phenols Adsorbed on Silica Gel with Diazomethane
Ogawa, Haruo,Hagiwara, Toshikazu,Chihara, Teiji,Teratani, Shousuke,Taya, Kazuo
, p. 627 - 630 (2007/10/02)
Alcohols and phenols adsorbed on silica gel react with diazomethane and quantitatively afford the corresponding methyl ethers.Alumina and titanium dioxide are also effective adsorbents for the reaction.
