695-02-3Relevant academic research and scientific papers
ORGANOFLUOROSILICATES IN ORGANIC SYNTHESIS. XV. REACTION OF exo- AND endo-5-NORBORNEN-2-YLSILYL DERIVATIVES WITH N-BROMOSUCCINIMIDE. DIFFERENCE IN REACTIVITY BETWEEN HEXACOORDINATE AND TETRACOORDINATE SILICON COMPOUNDS
Tamao, Kohei,Mishima, Masayuki,Yoshida, Jun-ichi,Takahashi, Masataka,Ishida, Neyoshi,Kumada, Makoto
, p. 151 - 162 (1982)
The reactions of potassium 5-norbornen-2-ylpentafluorosilicate (I) and 5-norbornen-2-yltrimethylsilane (II) with NBS were examined.The former reaction gave 3-nortricyclyl bromide (IV) as the only detectable product, arising from the carbon-silicon bond cleavage.The latter reaction, however, gave 3-bromo-1-nortricyclytrimethylsilane (V) as the major product, resulting from cleavage of the carbon-hydrogen bond α to silicon, together with IV and and unidentified product.GLC-monitoring of the reactions showed the higher reactivity of the norbornenyl derivative having the leaving group in the endo position irrespective of whether the leaving group is SiF5 or H.Since no inhibition was observed by the addition of hydroquinone in the dark, the reactions have been regarded as homoallylic electrophilic substitutions.A concerted mechanism seems to be consistent with the experimental data.Cleavage of 1-notricyclytrimethylsilane by iodine monochloride to give 1-iodonortricyclene has also been studied.
Regio- and stereochemical aspects of bromochlorination of norbornene
Zyk,Beloglazkina,Tyurin,Grishin
, p. 2220 - 2225 (2007/10/03)
Bromochlorination of norbornene whose chemo- and regio-selectivity is determined by the type of the halogenating reagent used was studied. Three isomeric bromochloronorbornanes (2-endo-bromo-3-exo-chloro-, 2-exo-bromo-3-endo-chloro-, and 2-exo-bromo-7-syn-chlorobicyclo[2.2.1.]heptanes), 2-exo-7-syn- and 2-exo-7-anti-dibromo- and -dichloro-norbornanes, and 2-bromonortricyclane were isolated and characterized by 1H and 13C NMR spectra. The spectral and structural characteristics of the resulting compounds are discussed.
The Surface Nature of Grignard Reagent Formation
Walborsky, H. M.,Topolski, Marek
, p. 3455 - 3459 (2007/10/02)
The reaction of exo-2-norbornyl bromide with Rieke magnesium in ether at -70 deg C in the presence of tert-butyl alcohol-O-d gave exclusively exo-2-deuterionorbornane whereas the epimer endo-2-norbornyl bromide yielded a 1:1 mixture of endo- and exo-2-deu
Efficient Utilization of Tetrabutylammonium Bifluoride in Halofluorination Reactions
Camps, F.,Chamorro, E.,Gasol, V.,Guerrero, A.
, p. 4294 - 4298 (2007/10/02)
The halofluorination reaction of a variety of alkenes by using tetrabutylammonium bifluoride (TBABF) in the presence of N-halosuccinimide is described.This process occurs stereospecifically to afford anti addition products, and with unsymmetrical olefins a marked Markovnikov-type regioselectivity is observed.In some cases, formation of a remarkable amount of the corresponding dihalo derivatives was found, but this undesirable side reaction can be avoided by using N-iodosucciniumide (NIS) as halogenating agent.If N-bromosuccinimide (NBS) or N-chlorosuccinimide (NCS) is utilized, these dihalo compounds can be easily removed from the halofluorinated compounds by simple column chromatography on silica gel.A mechanism for this side reaction is postulated.
DIFFERENTIAL BRIDGING IN THE SOLVOLYSIS OF 6- AND 7-SUBSTITUTED 2-EXO- AND 2-ENDO-NORBORNYL p-TOLUENESULFONATES
Flury, Peter,Grob, Cyril A.
, p. 3195 - 3198 (2007/10/02)
The large difference between the reaction constants ρI for the solvolysis of the 6-exo- and 7-anti-substituted norbornyl tosylates 3 and 7, respectively, is further proof for the hypothesis that 2-norbornyl cations are anisotropic with regard to the transmission of polar effects and that through space induction involves graded bridging.
Synthese und Hydrolyse von 6endo-substituierten p-Toluolsulfonsaeure-estern.
Grob, Cyril A.,Guenther, Bettina,Hanreich, Reinhard
, p. 2288 - 2298 (2007/10/02)
The Synthesis and Hydrolysis of 6endo-Substituted 2endo-Norbornyl p-Toluenesulfonates; The hydrolysis products of the p-toluenesulfonates of several hitherto unknown 6endo-substituted 2endo-norbornanols have been determined.
Cross-linked Poly-(4-vinylpyridine-styrene)-Bromine Complexes as Stereoselective Brominating Agents
Johar, Y.,Zupan, M.,Sket, B.
, p. 2059 - 2062 (2007/10/02)
Cross-linked poly(styrene-4-vinylpyridine) beads, containing 40-43percent of pyridine rings, were transformed with bromine to provide three types of brominating agents (1), (2), and (3).Reactions of cis- and trans-1-phenylpropene with (1), (2), and (3) resulted in a high degree of anti-stereoselectivity.The reactivity increases from (1) to (3); solvent polarity had no significant effect on stereoselectivity, but affects the reactivity, being significantly greater in acetonitrile and chloroform than in cyclohexane and dioxan.Bromination of 1-phenylcyclohexene with (1) and (3) resulted in the formation of trans-1,2-dibromo-1-phenylcyclohexane (9) and 3-bromo-2-phenylcyclohexene (10), the temperature affecting only the ratio of the products.Bromonation of norbornene with the reagents (1), (2) and (3) resulted in the formation of seven products: 2-exo-bromonorbornane (12), 7-bromonortricyclane (13), 2-exo,3-endo-dibromonorbornane (14), 2-exo-7-anti-dibromonorbornane (15), 2-exo,5-endo-dibromonorbornane (16), 2-exo,5-exo-dibromonorbornane (17), and 2-exo,7-syn-dibromonorbornane (18).
