Base catalysed rearrangements involving ylide intermediates. Part 18. Competing [1,2], [1,3], and [1,4] rearrangements of ammonium ylides

Asymmetric Ylide Reactions: Epoxidation, Cyclopropanation, Aziridination, Olefination, and Rearrangement

“…The concerted mechanism was therefore questioned. Ollis 145,146 carried out a series of elegant experiments and by careful analysis, they were able to show that the Stevens rearrangement proceeded by a radical pair intermediate 360. These radicals recombine rapidly before they have time to diffuse out of the solvent cage.…”

Oxidation and chlorination reactions of perfluoroketene-N,S-acetals

“…For this purpose, a chiral center should be presented in the starting molecule of N,S-acetal, which can influence the stereochemistry of the oxidation reaction with tert-butyl hydroperoxide. Thus, we have used chiral amine 14 [10] for the preparation of perfluoroketene-N,S-acetal 17 (Scheme 7).…”

“…in diethyl ether (40 ml), a solution of (S)-N-methyl-1-phenylethylamine [10] (4.86 g, 36 mmol, 1 eq.) and triethylamine (3.64 g, 36 mmol, 1 eq.)…”

Synthesis and Characterization of Chiral Guanidines und Guanidinium Salts Derived from 1-Phenylethylamine

“…First, (S)-phenethylamine (10) by formylation [28] and reduction with lithium aluminium hydride was converted to (S)-N-methyl-N-(1-phenylethyl)-amine (7), a known compound [30,31]. The (S, S)-bis-(methylphenethyl)-urea (8), a low melting solid, was formed with phosgene in toluene.…”