β-Oxidofunctionalized organolithium intermediates from ketones: a simple new access
作者:José Barluenga、José L. Fernández-Simón、José M. Concellón、Miguel Yus
DOI:10.1039/c39870000915
日期:——
Chloromethyl-lithium generated in situ, reacts at –78 °C with ketones (5) to afford, after lithiation with lithium naphthalenide, β-oxidoalkyl-lithium compounds (1), which on reaction with electrophiles (deuterium oxide, dimethyl disulphide, carbon dioxide, cyclohexanone, and allyl bromide) yield bifunctionalized compounds (6).
CIDNP (Chemically Induced Dynamic Nuclear Polarization) studies of the photoreduction of benzophenone by R-CH2-S-R' show evidence for the formation of vinylic deratives and adducts. The central intermediate in the reaction scheme is the radical pair R-CH-S-R' φ2-C-OHt. A study with selenides shows a different behaviour for these compounds.
Fluoride ion induced reaction of phenylthiomethyltrimethylsilane (1) with aldehydes and ketones: a simple procedure for the formation of β-hydroxyphenylsulphides
作者:John Kitteringham、Michael B Mitchell
DOI:10.1016/0040-4039(88)85151-7
日期:1988.1
The tetra -butylammonium fluoride (TBAF) initiated reaction of pheny1thiomethyltrimethysilane (1) with aldehydes and ketones is reported. ß-Hydroxy-phenylsulphides are formed in good yields even with ketones that contain enolisable protons. In contrast, the reaction of the organosilane (1) with pyridine -oxide failed to give any 2-phenylthiomethylpyridine. Methy1thiomethyltrimethylsilane (4) was found
The photoadduct formed by photolysis of the [Bapa(0), (pBzl)Phe(5), Met(O-2)(11)]SP/NK-1 complex localised within the (TMP175)-M-173 domain of the NK-1 receptor cannot be cleaved by CNBr on the C-side of methionine; an unusual rearrangement of the intermediate sulfonium instead Occurred. The reactivity of 1,1-diphenyl-2-methylsulfinyl ethanol 10 towards CNBr treatment and the stability of the 1,1-diphenyl oxirane 14 were analysed by NMR and mass spectrometry. 1,1-Diphenyl ethylene 13 can be formed from epoxide 14 even in slightly acidic conditions and during positive DCI/NH3 mass spectrometry analysis. Altogether, these results suggest that if a covalent linkage between the [Bapa(0), (pBzl)Phe(5), Met(O-2)(11)] and the NK-1 receptor occurred on the CyH2 of methionine-174, CNBr treatment will lead to an epoxide/ketone and an ethylenic compound. (C) 2002 Published by Elsevier Science Ltd.