39082-53-6Relevant articles and documents
Mild Darzens Annulations for the Assembly of Trifluoromethylthiolated (SCF3) Aziridine and Cyclopropane Structures
Delost, Michael D.,Njardarson, Jon T.
supporting information, p. 6121 - 6125 (2021/08/16)
We report mild new annulation approaches to trisubstituted trifluoromethylthiolated (SCF3) aziridines and cyclopropanes via Darzens inspired protocols. The products of these anionic annulations, rarely studied previously, possess attractive features rendering them valuable building blocks for synthesis platforms. In this study, trisubstituted acetophenone nucleophiles bearing SCF3 and bromine substituents in their α position were shown to undergo [2 + 1] annulations with vinyl ketones and tosyl-protected imines under mild reaction conditions.
Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton-Coupled Electron Transfer
Knowles, Robert R.,Metrano, Anthony J.,Tsuchiya, Yuto,Tsui, Elaine
supporting information, p. 11845 - 11849 (2020/05/22)
We report a catalytic, light-driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible-light irradiation in the presence of an IrIII-based photoredox catalyst, a Br?nsted base catalyst, and a hydrogen-atom transfer (HAT) co-catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct homolytic activation of alcohol O?H bonds through a proton-coupled electron-transfer mechanism. This method exhibits a broad substrate scope and high functional-group tolerance, and it accommodates a diverse range of alkene substitution patterns. Results demonstrating the extension of this catalytic system to carboetherification reactions are also presented.
Sulfones as Synthetic Linchpins: Transition-Metal-Free sp3–sp2 and sp2–sp2 Cross-Couplings Between Geminal Bis(sulfones) and Organolithium Compounds
Trost, Barry M.,Kalnmals, Christopher A.
, p. 9066 - 9074 (2018/06/29)
A valuable umpolung strategy that highlights the ambiphilic nature of the bis(phenylsulfonyl)methyl synthon and demonstrates its utility as a synthetic linchpin is reported. Although the bis(phenylsulfonyl)methyl group is typically introduced as an sp3-carbon nucleophile, it is demonstrated that it can also function as an effective sp2-carbon electrophile in the presence of organolithium nucleophiles. Alkyl- and aryllithiums couple with the central carbon of the bis(phenylsulfonyl)methyl unit to ultimately generate trisubstituted alkenes, comprising formal sp3–sp2 and sp2–sp2 cross-couplings between organolithium reagents and bis(sulfones). This process occurs almost instantaneously at ?78 °C in the absence of any transition metals. By developing this curious transformation, it has been demonstrated that bis(phenylsulfonyl)methane is a valuable synthetic linchpin, which can undergo two C?C bond-forming processes as an sp3-nucleophile, followed by a third C?C bond-forming reaction as an effective sp2-electrophile. This discovery significantly enhances the utility of this ubiquitous, but underutilized, linker group.
Fe-catalyzed allylic C-C-bond activation: Vinylcyclopropanes as versatile a1,a3,d5-synthons in traceless allylic substitutions and [3 + 2]-cycloadditions
Dieskau, Andre P.,Holzwarth, Michael S.,Plietker, Bernd
, p. 5048 - 5051 (2012/05/05)
The low-valent iron complex Bu4N[Fe(CO)3(NO)] (TBAFe) catalyzes the allylic C-C-bond activation of electron-poor vinyl cyclopropanes to generate synthetically useful a1,a3,d5-synthons which are prone to undergo multiple consecutive reactions. The versatility of this approach is demonstrated by a traceless allylic substitution and a formal [3 + 2] cycloaddition to give either functionalized acyclic products or densely substituted cyclopentanes and pyrrolidines in high yields and regioselectivities.
Access to high levels of molecular complexity by one-pot iridium/enamine asymmetric catalysis
Quintard, Adrien,Alexakis, Alexandre,Mazet, Clement
supporting information; experimental part, p. 2354 - 2358 (2011/04/22)
(Chemical Equation Presented) Independent workers with team spirit: A catalytic sequence that exploits the compatibility of (chiral) cationic iridium catalysts for the isomerization of primary allylic alcohols to aldehydes with organo-catalysts has been d
Highly enantioselective organocascade intermolecular iminium/enamine Michael addition on enals
Quintard, Adrien,Alexakis, Alexandre
supporting information; experimental part, p. 7212 - 7214 (2011/09/12)
An unprecedented intermolecular iminium/enamine Michael addition on enals has been developed by taking advantage of the high reactivity of vinyl sulfones. This powerful organocascade allows for the rapid construction of attractive synthons in high enantioselectivities (typically 99% ee).
Enantioselective organocatalytic conjugate addition of aldehydes to vinyl sulfones and vinyl phosphonates as challenging michael acceptors
Sulzer-Mosse, Sarah,Alexakis, Alexandre,Mareda, Jiri,Bollot, Guillaume,Bernardinelli, Gerald,Filinchuk, Yaroslav
supporting information; experimental part, p. 3204 - 3220 (2009/12/03)
Chiral amines with a pyrrolidine framework catalyze the enantioselective conjugate addition of a broad range of aldehydes to various vinyl sulfones and vinyl phosphonates in high yields and with enantioselectivities up to >99% ee. This novel process provides synthetically useful chiral γ-gem-sulfonyl or phosphonyl aldehydes which can be widely functionalized with retention of the enantiomeric excess. Mechanistic insights including DFT calculations are explored in detail.
