205701-99-1Relevant articles and documents
Oxidation Under Reductive Conditions: From Benzylic Ethers to Acetals with Perfect Atom-Economy by Titanocene(III) Catalysis
Funk, Pierre,Richrath, Ruben B.,Bohle, Fabian,Grimme, Stefan,Gans?uer, Andreas
supporting information, p. 5482 - 5488 (2021/02/03)
Described here is a titanocene-catalyzed reaction for the synthesis of acetals and hemiaminals from benzylic ethers and benzylic amines, respectively, with pendant epoxides. The reaction proceeds by catalysis in single-electron steps. The oxidative addition comprises an epoxide opening. An H-atom transfer, to generate a benzylic radical, serves as a radical translocation step, and an organometallic oxygen rebound as a reductive elimination. The reaction mechanism was studied by high-level dispersion corrected hybrid functional DFT with implicit solvation. The low-energy conformational space was searched by the efficient CREST program. The stereoselectivity was deduced from the lowest lying benzylic radical structures and their conformations are controlled by hyperconjugative interactions and steric interactions between the titanocene catalyst and the aryl groups of the substrate. An interesting mechanistic aspect is that the oxidation of the benzylic center occurs under reducing conditions.
Chiral initiator-induces self-disproportionation of enantiomers via achiral chromatography: Application to enantiomer separation of racemate
Tateishi, Kaori,Tsukagoshi, Shiori,Nakamura, Tsuyoshi,Watanabe, Shotaro,Soloshonok, Vadim A.,Kitagawa, Osamu
supporting information, p. 5220 - 5223 (2013/09/02)
We report here the theoretical design and proof of principle of the first example of a conceptually new approach for the preparation of enantiomerically pure compounds from the racemates by chiral initiator-induced Self-Disproportionation of Enantiomers (SDE) via achiral chromatography.
A process for the preparation of rivastigmine or a salt thereof
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Page/Page column 10, (2008/12/04)
There are provided processes for making rivastigmine. In one embodiment, the process includes reacting S-(-)-[1-(3-hydroxyphenyl)ethyl]dimethylamine with N-ethyl-N-methyl carbamoyl chloride in the presence of an organic base to obtain a free base of rivastigmine.