7231-40-5Relevant articles and documents
Menthylamine synthesis via gold-catalyzed hydrogenation of menthone oxime
Demidova, Yu. S.,Mozhaitsev, E. S.,Murzin, D. Yu.,Nefedov, A. A.,Salakhutdinov, N. F.,Saraev, A. A.,Simakov, A.,Simakova, I. L.,Suslov, E. V.,Volcho, K. P.
, (2020/09/03)
In the current work gold nanoparticles supported on oxides (MgO, Al2O3, ZrO2, TiO2) were used for menthylamine synthesis via menthone oxime hydrogenation. An increase of the gold nanoparticles size and application of metal oxides with a strong basic character such as magnesia favored deoximation to menthone. Au/Al2O3 catalyst with the gold nanoparticles size of 2.0 nm afforded high catalytic activity and selectivity to menthylamine. The reaction kinetics including stereoselectivity to the reaction products and recyclability of the catalyst was studied using Au/Al2O3 in the temperature range 90?110 °C under hydrogen pressure of 5.5–7.5 bar. The catalytic behavior was influenced by the solvent nature, with higher selectivity to desired amine achieved using methanol. The reaction rate was pressure independent, while has first order with respect to menthone oxime concentration. Stereoselectivity to menthylamines and menthones was independent on the reaction temperature and the hydrogen pressure.
Triiodide-Mediated δ-Amination of Secondary C?H Bonds
Wappes, Ethan A.,Fosu, Stacy C.,Chopko, Trevor C.,Nagib, David A.
, p. 9974 - 9978 (2016/08/16)
The Cδ?H amination of unactivated, secondary C?H bonds to form a broad range of functionalized pyrrolidines has been developed by a triiodide (I3?)-mediated strategy. By in situ 1) oxidation of sodium iodide and 2) sequestration of the transiently generated iodine (I2) as I3?, this approach precludes undesired I2-mediated decomposition which can otherwise limit synthetic utility to only weak C(sp3)?H bonds. The mechanism of this triiodide-mediated cyclization of unbiased, secondary C(sp3)?H bonds, by either thermal or photolytic initiation, is supported by NMR and UV/Vis data, as well as intercepted intermediates.
Efficient resolution of menthylamine with inexpensive (r,r)-tartaric acid by dielectrically controlled resolution (DCR)
Schmitt, Magdalena,Schollmeyer, Dieter,Waldvogel, Siegfried R.
, p. 1007 - 1012 (2014/03/21)
A practical procedure for the resolution of menthylamine 2 with (R,R)-tartaric acid [(R,R)-3] as resolving agent is presented. Variation of the solvent system allows both enantiomers of 2 to be selectively crystallized. Performing the resolution in methanol containing 6 % water leads to (-)-2·(R,R)-3·MeOH. The other, less-soluble diastereomeric salt is obtained by applying a solvent system consisting of methanol with 19 % water with a yield of 14 %. Subsequent basic workup with aqueous sodium hydroxide gave the free menthylamine compounds. Further workup of the mother liquors and an additional recrystallization step allowed the (-)-2·(R,R)-3·MeOH salt to be obtained in an overall yield of 22 %; the other salt (+)-2·(R,R)-3·MeOH·H2O was obtained in 23 % yield. This is another important example of the dielectrically controlled resolution of an interesting amine by using inexpensive (R,R)-tartaric acid as resolving agent. With the same inexpensive resolving agent, (R,R)-tartaric acid, both antipodes of menthylamine can be selectively crystallized as diastereomeric salts. The concentration of water determines which salt is formed. In a few simple resolution steps, good yields and high enantiomeric excess can be achieved. Copyright
