2463-63-0Relevant articles and documents
Enhancing the photo-efficacy of an organic visible-light-activated chromophore (alizarin red S) on zinc oxide with a Ag-Na electrolyte to photo-transform aromatic and aliphatic alcohols
Underwood, Timothy M.,Robinson, Ross S.
, p. 24259 - 24266 (2019)
The development of an aqueous silver-sodium/alizarin red sensitised zinc oxide system has been reported to oxidise a range of both aromatic and aliphatic alcohols to aldehydes. Furthermore, photoluminescence spectroscopy validated the electron quenching effect of zinc oxide's defect sites after surface sensitising the metal-oxide with alizarin red. Powder diffuse reflectance UV/Vis data further substantiated the visible-light attenuated properties of alizarin red sensitised zinc oxide, and hence justification for its visible light reactivity towards alcohol oxidations. Lastly, density functional theory calculations supported the intermolecular photo-electronic transfer between alizarin red organic and zinc oxide.
Enantioselective Organocatalytic Synthesis of 1,2,3-Trisubstituted Cyclopentanes
?otolová, Martina,Kamlar, Martin,Reme?, Marek,Géant, Pierre-Yves,Císa?ová, Ivana,?tícha, Martin,Vesely, Jan
, p. 5080 - 5089 (2021/09/30)
An organocatalytic asymmetric domino Michael/α-alkylation reaction between enals and non-stabilized alkyl halides has been developed. Chiral secondary amine catalyzed cyclization reaction of 1-bromo-3-nitropropane with α,β-unsaturated aldehydes provides 1,2,3-trisubstituted cyclopentane carbaldehydes with high diastereo- (dr up to 8 : 1) and enantioselectivities (ee up to 96 %).
Stable gold(III) catalysts by oxidative addition of a carbon-carbon bond
Wu, Chung-Yeh,Horibe, Takahiro,Jacobsen, Christian Borch,Toste, F. Dean
, p. 449 - 454 (2015/03/04)
Low-valent late transition-metal catalysis has become indispensable to chemical synthesis, but homogeneous high-valent transition-metal catalysis is underdeveloped, mainly owing to the reactivity of high-valent transition-metal complexes and the challenges associated with synthesizing them. Here we report a carbon-carbon bond cleavage at ambient conditions by a Au(i) complex that generates a stable Au(iii) cationic complex. In contrast to the well-established soft and carbophilic Au(i) catalyst, this Au(iii) complex exhibits hard, oxophilic Lewis acidity. For example, we observed catalytic activation of α,β-unsaturated aldehydes towards selective conjugate additions as well as activation of an unsaturated aldehyde-allene for a [2 + 2] cycloaddition reaction. The origin of the regioselectivity and catalytic activity was elucidated by X-ray crystallographic analysis of an isolated Au(iii)-activated cinnamaldehyde intermediate. The concepts revealed suggest a strategy for accessing high-valent transition-metal catalysis from readily available precursors.
Combined heterogeneous metal/chiral amine: Multiple relay catalysis for versatile eco-friendly synthesis
Deiana, Luca,Jiang, Yan,Palo-Nieto, Carlos,Afewerki, Samson,Incerti-Pradillos, Celia A.,Verho, Oscar,Tai, Cheuk-Wai,Johnston, Eric V.,C?rdova, Armando
supporting information, p. 3447 - 3451 (2014/04/03)
Herein is described a versatile and broad synergistic strategy for expansion of chemical space and the synthesis of valuable molecules (e.g. carbocycles and heterocycles), with up to three quaternary stereocenters, in a highly enantioselective fashion from simple alcohols (31 examples, 95:5 to >99.5:0.5 e.r.) using integrated heterogeneous metal/chiral amine multiple relay catalysis and air/O2 as the terminal oxidant. A novel highly 1,4-selective heterogeneous metal/amine co-catalyzed hydrogenation of enals was also added to the relay catalysis sequences. Relay switch: A versatile strategy for expansion of chemical space and the synthesis of valuable molecules, having up to three quaternary stereocenters, in a highly enantioselective fashion from simple alcohols is described. The method employs integrated heterogeneous metal/chiral amine multiple relay catalysis and air/O2 as the terminal oxidant.
Synthesis of α,β-unsaturated aldehydes and methyl carboxylic esters from 2-acetylenic phenyl sulfides
Fortes, Carlos C.,Garrote, Clevia F. D.
, p. 3917 - 3941 (2007/10/03)
2-Alkynylthio benzenes were reduced to 2-Alkenylthio benzenes with diisobutyl aluminum hydride. Mono chlorination of these compounds with sulfuryl chloride and pyridine followed by hydrolysis, in the presence of Cu(II) salts, gave α,β-unsaturated aldehydes. 2-Alkynylthio benzenes were converted into 2-Alkynyl 1,1-bis thiobenzenes by monochlorination with sulfuryl chloride and pyridine followed by treatment with thiophenol and triethylamine. These substances were then converted to α,β-unsaturated methyl carboxylic esters by way of isomerization with sodium methoxide to the corresponding allene and treatment with hydrochloric acid and methanolysis in the presence of iodine.
AN EFFICIENT REAGENT FOR SYNTHESIS OF α,β-UNSATURATED ALDEHYDES 3-METHYLTHIO-2-PROPENYL p-TOLYL SULFONE
Ogura, Katsuyuki,Iihama, Teruyuki,Takahashi, Kazumasa,Iida, Hirodata
, p. 2671 - 2674 (2007/10/02)
Alkylation of 3-methylthio-2-propenyl p-tolyl sulfone (1) with an alkyl halide and a base (NaH or KOH-TOMAC) took place at the position α to the sulfonyl group to give optionally a mono- or dialkylated product (2 or 3), which was converted to β-monosubstituted or β,β-disubstituted α,β-unsaturated aldehyde (6 or 7), respectively, by TiCl4-assisted hydrolysis followed by the removal of p-toluenesulfinic acid.
