Phenanthroline and tert-butoxide have been established as powerful radical initiators in reactions such as the S(RN)1-type coupling reactions due to the cooperation of large heteroarenes and a special feature of tert-butoxide. The first phenanthroline-tert-butoxide-catalyzed transition-metal-free allylic isomerization is described. The resulting ketones are key intermediates for indenes. The control experiments rule out the base-promoted allylic anion pathway. The radical pathway is supported by experimental evidence that includes kinetic study, kinetic isotope effect, isotope-labeling experiments, trapping experiments, and EPR experiments.
Copper-Mediated Cross-Dehydrogenative Coupling of 2-Methylpyridine and 8-Methylquinoline with Methyl Ketones and Benzamides
作者:Gadde Sathish Kumar、Joshua William Boyle、Ciputra Tejo、Philip Wai Hong Chan
DOI:10.1002/asia.201501096
日期:2016.2
synthetic method to prepare (E)‐(pyridin‐2‐yl)enones and (E)‐(quinolin‐8‐yl)enones that relies on the respective copper(I)‐catalyzed formal cross‐dehydrogenative coupling (CDC) reaction of 2‐methylpyridine and 8‐methylquinoline with methyl ketones has been discovered. The mechanism was delineated to follow a pathway involving oxidation of the N‐heterocycle to its corresponding aldehyde adduct prior
Iron-Facilitated Oxidative Radical Decarboxylative Cross-Coupling between α-Oxocarboxylic Acids and Acrylic Acids: An Approach to α,β-Unsaturated Carbonyls
The first Fe-facilitated decarboxylative cross-coupling reaction between α-oxocarboxylicacids and acrylic acids in aqueous solution has been developed. This transformation is characterized by its wide substrate scope and good functional group compatibility utilizing inexpensive and easily accessible reagents, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated
[EN] A METHOD FOR PREPARING SULFUR-CONTAINING COMPOUNDS<br/>[FR] PROCÉDÉ POUR LA PRÉPARATION DE COMPOSÉS CONTENANT DU SOUFRE
申请人:ROYAL COLLEGE OF SURGEONS IE
公开号:WO2010066450A1
公开(公告)日:2010-06-17
The invention provides a method for preparing sulfur-containing compounds, the method comprising reacting a donor compound comprising at least one sulfur having at least one lone pair of electrons, with an acceptor compound; wherein the reaction occurs in the presence of an amine, optionally an amine catalyst, capable of activating the sulfur having at least one lone pair of electrons; and wherein the reaction occurs via the formation of an transient intermediate species, optionally a transient intermediate species, between the amine, optionally the amine catalyst and the donor compound; and wherein the donor compound is selected from the group consisting of a sulfurous acid, a sulfenic acid and a sulfinic acid or a salt, ester or amide of a sulfurous acid, a sulfenic acid and a sulfinic acid. The invention also provides sulfur-containing compounds of the formula: wherein R is selected from: (a) 1 -(4-Nitro-phenyl)-3-oxo-3-phenyl-propane; (b) 2-(3-Methyl-4-nitro-isoxazol-5-yl)-1 -phenyl-ethane; (c) 1-(4-Methoxy-phenyl)-2-(3-methyl-4-nitro-isoxazol-5-yl)-ethane; (d) 2-(3-Methyl-4-nitro-isoxazol-5-yl)-1-(4-nitro-phenyl)-ethane; (e) 1-(4-Fluoro-phenyl)-2-(3-methyl-4-nitro-isoxazol-5-yl)-ethane; (f) 1 -(4-Chloro-phenyl)-2-(3-methyl-4-nitro-isoxazol-5-yl)-ethane; and (g) 3-Oxo-cyclohexane. Finally, the invention provides use of chiral sulfur-containing compounds obtainable by the above-mentioned method or chiral sulfur-containing compounds as mentioned above for the resolution of racemic mixtures of amines.
Methylene-Bridged Bis(imidazoline)-Derived 2-Oxopyrimidinium Salts as Catalysts for Asymmetric Michael Reactions
作者:Andrey E. Sheshenev、Ekaterina V. Boltukhina、Andrew J. P. White、King Kuok Mimi Hii
DOI:10.1002/anie.201300614
日期:2013.7.1
In nothing flat: The title salts, having planar nitrogen centers, were utilized successfully as phase‐transfer catalysts for asymmetricMichaelreactions of tert‐butyl glycinate benzophenone Schiff base with vinyl ketone and chalcone derivatives, thus providing excellent levels of diastereo‐ and enantiocontrol (see scheme).
Novel Enantioselective Synthesis of Functionalized Pyridylarsanes by a Chiral Palladium Template Promoted Asymmetric Hydroarsanation Reaction
作者:Fengli Liu、Sumod A. Pullarkat、Yongxin Li、Shuli Chen、Pak‐Hing Leung
DOI:10.1002/ejic.200900460
日期:2009.9
hydroarsanation reaction with (E)-1-methyl-3-(pyridin-2-yl)-2-propenoate gave only one product as a six-membered As–N bidentate chelate. The naphthylamine auxiliary could be removed chemoselectively by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral complexes. Subsequent ligands displacement from the palladium using aqueous potassiumcyanide generated the