Highly Productive α-Alkylation of Ketones with Alcohols Mediated by an Ir–Oxalamidato/Solid Base Catalyst System
作者:Hideo Shimizu、Hironori Maeda、Hideki Nara
DOI:10.1021/acs.oprd.0c00362
日期:2020.11.20
An Ir–oxalamidato complex in combination with a solid base (e.g., magnesium aluminometasilicate/Ca(OH)2) significantly improved the catalyst productivity in α-alkylation of methyl ketones with primary alcohols. Optimization through systematic variation of the oxalamidato ligand led to a practical turnover number (TON) of 10 000–40 000.
Die Addition von 1-Lithio-1-(phenylthio)alkanen an 2-(<i>N</i>-Methylanilino)acrylnitril: Ein einfacher Weg zu 3-(Phenylthio)ketonen und 2-Enonen
作者:Hubertus Ahlbrecht、Marcellinus Ibe
DOI:10.1055/s-1988-27514
日期:——
The Addition of 1-Lithio-1-(phenylthio)alkanes to 2-(N-Methylanilino)-acrylonitrile: An Easy Access to 3-(Phenylthio)ketones and 2-Enones A simple and versatile strategy for the synthesis of the title compounds is described. The key-step consists in the addition of 1-lithio-1-(phenylthio)alkanes to 2-(N-methylanilino)acrylonitrile, the nucleophilic phenylthioalkylation of an enol-cation equivalent. Alkylation of the adducts and hydrolysis give 3-(phenylthio)ketones, which can be isolated, or without further purification can be transformed into 2-enones via the wellknown oxidation-elimination procedure. These reactions are possible with allylic derivatives too, therefore the homologous vinylic compounds can be prepared by the same way. Pyrolysis of the 1-lithioaminonitriles formed within the first step gives aminonitriles of cyclopropanones via cyclization.
Oxidation of olefins with 2-pyridineseleninic anhydride
作者:Derek H.R. Barton、David Crich
DOI:10.1016/s0040-4020(01)97207-2
日期:1985.1
2-Pyridineseleninic anhydride, prepared in situ by oxidation of the corresponding diselenide with iodoxybenzene, is an efficient reagent for the conversion of olefins to unsaturated ketones with retention of the original position of the double bond. This reagent is, therefore, much more reactive towards olefins than benzeneseleninicanhydride. An explanation has been offered.
Reactivity of the 1-t.butylthio-3-methoxy-1-alkenes towards metalating agents, II. Allylic deprotonation of the E-isomers and of the Z-propenyl derivative.
作者:O. Ruel、C.Bibang Bi Ekogha、S.A. Julia
DOI:10.1016/s0040-4039(00)94018-8
日期:1983.1
Deprotonation of the title compounds with a lithiating agent and subsequent alkylation furnish the 1-substituted products . The 1-t.butylthio-3-methoxy-1-lithio-1-alkenes become newequivalents of the hypothetical anions I.