481660-35-9Relevant articles and documents
Rhodium catalyzed hydroformylation of β-pinene and camphene: effect of phosphorous ligands and reaction conditions on stereoselectivity
Barros, Humberto J. V.,Ospina, Maria L.,Arguello, Eduardo,Rocha, William R.,Gusevskaya, Elena V.,Santos, Eduardo N. dos
, p. 150 - 157 (2007/10/03)
The effect of phosphorous ligands on the rhodium catalyzed hydroformylation of β-pinene and camphene has been studied. In unmodified systems, β-pinene undergoes a fast isomerization to α-pinene. At longer reaction times and higher temperatures, the isomerization equilibrium is shifted resulting in the 80 percent chemoselectivity for β-pinene hydrofromylation products (97 percent trans). The addition of various diphosphines or phosphites improves the chemoselectivity and shifts the hydroformylation towards cis aldehyde 3a. Both the rate and diastereoselectivity of the hydroformylation of β-pinene are largely influenced by the basicity of auxiliary ligands, but surprisingly no correlation between their steric characteristics and the diastereoselectivity of the catalytic system has been revealed for the ligands with cone angles 128-165 deg. The systems with more basic ligands show lower activities, higher diastereoselectivities and usually higher chemoselectivities in the β-pinene hydroformylation. Camphene gives linear aldehyde 6, with virtually 100 percent regio- and chemoselectivity in both modified and unmodified systems. The addition of phosphorous ligands favors the formation of endo isomer 6b:6a/6b ca. 1/1.5 , whereas the ratio ca. 1/1 unmodified systems. Neither steric nor electronic parameters of the ligands have been found to influence significantly the diastereoselectivity of the camphene hydroformylation.
Reactions of epoxides prepared from some monoterpenes with acetic anhydride on aluminosilicate catalysts
Tatarova,Korchagina,Volcho,Salakhutdinov,Barkhash
, p. 1076 - 1082 (2007/10/03)
Reactions of epoxides prepared from α-, β-pinenes and camphene with acetic anhydride on aluminosilicate catalysts (clay K-10, zeolite β) were investigated affording various products of skeleton rearrangements: mono- and diacetates with five- and six-membered rings, and also with norbornane and pinane cores.
Acid-catalyzed reactions of camphene and α-fenchene epoxides
Yarovaya,Korchagina,Gatilov,Barkhash
, p. 810 - 822 (2007/10/03)
Isomerization of camphene and α-fenchene epoxides under homogeneous and heterogeneous conditions in media of various acidity was studied. The intermolecular reactions of these epoxy compounds with unsaturated aldehydes, allyl alcohol and methanol on askanite-bentonite clay yielded spiroacetals, and open-chain hydroxyethers and acetals. The results obtained are compared to those for reactions with the initial monoterpenes.
Convenient preparation of carbonyl compounds from 1,2-diols utilizing Mitsunobu conditions
Barrero, Alejandro F.,Alvarez-Manzaneda, Enrique J.,Chahboun
, p. 1959 - 1962 (2007/10/03)
1,1-Disubstituted 1,2-diols are efficiently converted into carbonyl compounds by reaction with triphenylphosphine and diethyl azodicarboxylate. (C) 2000 Elsevier Science Ltd.
One-pot conversion of olefins to carbonyl compounds by hydroboration/NMO-TPAP oxidation
Yates, Matthew H.
, p. 2813 - 2816 (2007/10/03)
An efficient method to oxidize an olefin to the less substituted carbonyl compound is described. This new methodology utilizes borane dimethyl sulfide followed by tetrapropylammonium perruthenate N-methylmorpholine N-oxide to oxidize the resulting alkylborane.
Methyltrioxorhenium(VII)-katalysierte Epoxydierung von Alkenen mit Harnstoff-Wasserstoffperoxid
Adam, Waldemar,Mitchell, Catherine M.
, p. 578 - 581 (2007/10/03)
Keywords: Asymmetrische Synthesen; Epoxidierungen; Katalyse; Komplexe mit Sauerstoffliganden; Rheniumverbindungen
Oxygenation of Oleefinic Hydrocarbons Catalyzed by Iron(II) Acetonitrile Solvate
Kobayashi, Shigeki,Kotani, Eiichi,Ishii, Yoko,Tobinaga, Seisho
, p. 610 - 614 (2007/10/02)
Oxygenation reactions of olefins having an endo- or exo-cyclic double bond, namely, cyclohexene, norbornene, camphene, longifolene, and ent-kaurene, with a simple model reagent, Fe(MeCN)62+-H2O2-Ac2O, for mono-oxygenase were investigated in connection with their biotransformations.Keywords oxygenation; olefin; endo-cyclic double bond; exo-cyclic double bond; iron(II) acetonitrile solvate; hydrogen peroxide; model enzyme; mono-oxygenase
PHOTOCHEMISTRY OF ORGANIC HALIDES: SOME INTERESTING FEATURES OF THE PHOTOBEHAVIOUR OF VINYL HALIDES AND VINYLIDENE DIHALIDES DERIVED FROM CAMPHENE
Sonawane, H. R.,Nanjundiah, B. S.,Panse, M. D.
, p. 3507 - 3510 (2007/10/02)
A study of the photochemistry of vinylidine dihalides 1 and 2 and vinylhalides 4 and 5 revealed some interesting differences in their photobehaviour.This study led to uncover an important constraint in the generation of vinyl cations from certain α-unsubstituted vinyl halides such as 4.
ω-Methylcamphene/ω,ω-Dimethylcamphene: Synthesis and Reactions
Lamture, J. B.,Nayak, U. R.
, p. 853 - 858 (2007/10/02)
ω-Methylcamphene (8)/ω,ω-Dimethylcamphene (9) have been synthesized by two routes; (i) the Prins reaction on camphene (1)/ω-methylcamphene (8) and (ii) olefination with methylenetriphenylphosphorane of the aldehyde (17)/methyl ketone (24) followed by isomerization of the resulting hydrocarbon with N-lithioethylenediamine.Camphenilone (2) also undergoes a direct Wittig reaction with ethylidenephosphorane (27) yielding 8 (E/Z)-mixture but fails to react with isopropylidenephosphorane (28) in an attempt to generate 9.Camphene (1) and its ω-methyl homologues 8/9 undergo normal epoxidation with perbenzoic acid without excess consumption of peracid.Lewis acid-catalyzed rearrangement of the resulting epoxides 16/23/29 has also been studied.The Hg(OAc)2/NaCl reaction on 8 yields the crystalline ω-methyl-ω-mercurichloride (10) transformed by pyridine perbromide into the ω-bromo-ω-methylcamphene (11).
