5937-40-6Relevant academic research and scientific papers
Amphiphilic Reactions by Means of Exceptionally Bulky Organoaluminum Reagents. Rational Approach for Obtaining Unusual Equatorial, Anti-Cram, and 1,4 Selectivity in Carbonyl Alkylation
Maruoka, Keiji,Itoh, Takayuki,Sakurai, Minoru,Nonoshita, Katsumasa,Yamamoto, Hisashi
, p. 3588 - 3597 (2007/10/02)
Exceptionally bulky, oxygenophilic organoaluminum reagents, methylaluminum bis(2,6-di-tert-4-alkylphenoxide) (MAD and MAT), have been successfully utilized for stereoselective activation of carbonyl moiety.Combination of MAD or MAT with carbon nucleophiles such as organolithiums or Grignard reagents generates a new amphiphilic reaction system in which the alkylation may be interpreted as the nucleophilic addition of a reactive organometallic compound to an electrophilically activated carbonyl substrate in order to account for the regio- and stereochemical consequences.In contrast to the ordinary alkylations, the amphilic alkylation disclosed herein would be categorized into the new, yet unexplored class of alkylation that exhibits high chemoselectivity to carbonyl compounds, and more significantly it allows excellent equatorial and anti-Cram selectivity in carbonyl alkylations, hitherto difficult by the existing methodologies.Further, unusual conjugate addition of organolithium reagents to α,β-unsaturated carbonyl compounds has been accomplished by using the amphiphilic reaction system.
Reactions of 1-Methyl-4-t-butylcyclohexene and 1-Methylcyclohexene with Thallium(I) Acetate-Iodine
Cambie, Richard C.,Hume, Bruce A.,Rutledge, Peter S.,Woodgate, Paul D.
, p. 413 - 419 (2007/10/02)
Treatment of 1-methyl-4-t-butylcyclohexene (2) with thallium(I)acetate-iodine in wet acetic acid at 90 deg C gives a complex mixture of products, which differs from that obtained from a Woodward reaction with silver(I) acetate followed by hydrolysis and which includes the unexpected hydroxy-iodoacetate (25).At 20 deg C the thallium(I)-mediated reaction gives a mixture of regioisomeric iodo-acetates.A re-investigation of the reaction of thallium(I) acetate-iodine with 1-methylcyclohexene (1) at 20 deg C has shown that this is not highly regioselective as reported earlier.The actions of KOAc-I2-18-crown-6 and iodine(III) triacetate in acetic acid on the alkenes (1) and (2), and of I2-H2O in tetramethylene sulphone-chloroform on the alkene (2) are reported.
Mechanism of the Liquid-Phase Catalytic Hydrogenolysis on Palladium/Carbon of Cyclohexene Epoxides
Accrombessi, Georges C.,Geneste, Patrick,Olive, Jean-Louis,Pavia, Andre A.
, p. 4139 - 4143 (2007/10/02)
Heterogeneous catalytic hydrogenolysis of cyclohexene epoxides on 10percent Pd/C was studied in different solvents. The principal products were found to be alcohols, formed by cleavage of one epoxide C-O bond. In addition, simultaneous cleavage of both C-O bonds gave hydrocarbons, and isomerization on the catalyst gave ketones as byproducts. The deuterolysis of cis- and trans-tert-butylcyclohexene epoxides and kinetic studies with cyclohexene epoxides carrying an axial methyl group in position 3 or 5 showed that hydrogenolysis gives preferentially axial alcohols and trans hydrogen addition, after a "roll over" on the catalyst. If one epoxide carbon carries a methyl group, conformational and steric factors come into play. C-O bond cleavage at the more substituted carbon, leading to equatorial alcohols, becomes competitive with preferential formation of axial alcohols, and steric hindrance to molecular reorientation on the catalyst causes cis as well as trans hydrogen addition.
