150982-69-7Relevant articles and documents
Highly enantioselective synthesis of chiral tetrahydroquinolines and tetrahydroisoquinolines by ruthenium-catalyzed asymmetric hydrogenation in ionic liquid
Ding, Zi-Yuan,Wang, Tianli,He, Yan-Mei,Chen, Fei,Zhou, Hai-Feng,Fan, Qing-Hua,Guo, Qingxiang,Chan, Albert S. C.
supporting information, p. 3727 - 3735 (2014/01/06)
Asymmetric hydrogenation reactions of quinolines and 3,4- dihydroisoquinolines using the chiral cationic ruthenium complex Ru(TsDPEN) [TsDPEN=N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine] as catalyst in neat imidazolium ionic liquids have been investigated. The catalytic performance was influenced by the anion of the ionic liquids for both substrate classes. A range of 2-alkyl-substituted 1,2,3,4-tetrahydroquinolines and 1-alkyl-substituted 1,2,3,4-tetrahydroisoquinolines was obtained in high yields with up to >99% ee. Interestingly, the hydrogenation of quinoline derivatives bearing a carbonyl group was selective for the C-N (quinoline) over the C-O (ketone) bonds, while such a unique chemoselectivity was not observed in methanol. Furthermore, the ruthenium catalysts could be easily recycled at least 5 times in the asymmetric hydrogenation of 3,4-dihydroisoquinoline by solvent extraction. To further facilitate the recovery of catalyst and reduce the use of organic solvent, a thin film of ionic liquid containing Ru(TsDPEN) was supported on silica gels. This supported ionic liquid-phase catalyst was effective in the asymmetric hydrogenation of quinoline, and could be recycled at least 6 times by simple filtration. Copyright
Photochemical preparation of highly functionalized 1-indanones
Wessig, Pablo,Glombitza, Clemens,Mueller, Gunnar,Teubner, Janek
, p. 7582 - 7591 (2007/10/03)
A series of o-alkylphenyl alkyl ketones 1 were synthesized by different methods. The presence of a leaving group X adjacent to the carbonyl group is the special peculiarity of these ketones. Upon irradiation the keto carbonyl group of these compounds undergoes an n-π* excitation followed by a 1,5-hydrogen migration from the o-alkyl substituent to the carbonyl oxygen atom. The thus formed 1,4-diradicals are subject to a very rapid elimination of acid HX, giving 1,5-diradicals. We called this process spin center shift. After intersystem crossing these diradicals cyclize to 1-indanones 20 in good yields. Depending on the solvent and on substituents, o-alkoxyalkyl ketones 22 or benzo-[c]furanes 21 are obtained as byproducts. The mechanism of the cyclization was elucidated by quantum chemical calculations and kinetic measurements.
Protoberberines from Reissert compounds, II: A new synthesis of 8-methyldibenzo[a,g]quinolizidines
Reimann,Renz
, p. 253 - 258 (2007/10/02)
The Reissert compounds 16 are benzylated by 2-bromomethylacetophenone dioxolane 14 to give the dihydroisoquinolines 5. Treatment of 5 with KOH yields the 1-benzylisoquinolines 6 which spontaneously form the deoxygenated coralynes 4 in acidic solution. 4a
