20023-36-3Relevant academic research and scientific papers
Scalable and safe synthetic organic electroreduction inspired by Li-ion battery chemistry
Peters, Byron K.,Rodriguez, Kevin X.,Reisberg, Solomon H.,Beil, Sebastian B.,Kawamata, Yu,Baran, Phil S.,Hickey, David P.,Klunder, Kevin,Gorey, Timothy J.,Anderson, Scott L.,Minteer, Shelley D.,Collins, Michael,Starr, Jeremy,Chen, Longrui,Udyavara, Sagar,Neurock, Matthew
, p. 838 - 845 (2019/04/30)
Reductive electrosynthesis has faced long-standing challenges in applications to complex organic substrates at scale. Here, we show how decades of research in lithium-ion battery materials, electrolytes, and additives can serve as an inspiration for achieving practically scalable reductive electrosynthetic conditions for the Birch reduction. Specifically, we demonstrate that using a sacrificial anode material (magnesium or aluminum), combined with a cheap, nontoxic, and water-soluble proton source (dimethylurea), and an overcharge protectant inspired by battery technology [tris(pyrrolidino)phosphoramide] can allow for multigram-scale synthesis of pharmaceutically relevant building blocks. We show how these conditions have a very high level of functional-group tolerance relative to classical electrochemical and chemical dissolving-metal reductions. Finally, we demonstrate that the same electrochemical conditions can be applied to other dissolving metal-type reductive transformations, including McMurry couplings, reductive ketone deoxygenations, and epoxide openings.
Sequential Birch reaction and asymmetric Ir-catalyzed hydrogenation as a route to chiral building blocks
Paptchikhine, Alexander,Itto, Kaori,Andersson, Pher G.
supporting information; experimental part, p. 3989 - 3991 (2011/06/09)
A range of 1,2,4-trisubstituted cyclohexadienes obtained from the Birch reaction were hydrogenated asymmetrically to produce synthetically valuable chiral compounds in high enantio- and diastereoselectivity. The Royal Society of Chemistry.
SmI2/H2O/amine promoted reductive cleavage of benzyl-heteroatom bonds: optimization and mechanism
Ankner, Tobias,Hilmersson, G?ran
experimental part, p. 10856 - 10862 (2010/02/28)
The SmI2/H2O/pyrrolidine mediated cleavage of benzylic alcohols and benzyl groups was studied and found to be a viable alternative to the Birch reduction yielding the corresponding deoxygenated product in excellent yield. The reaction has been investigated by kinetic methods, and a mechanism involving a pre-complexation of the alcohol to SmI2 followed by an amine mediated electron transfer and subsequent bond cleavage and transfer of a second electron and proton to yield the toluene product has been proposed. The reaction is strongly inhibited at higher concentrations of water, indicating that it proceeds via an inner-sphere electron transfer from samarium(II) to the benzyl group, and excess of water prevents coordination of benzyl alcohol to samarium.
Synthesis of 4-hydroxy-4-methylcyclohex-2-en-1-one
Parladar, Vesile,Gueltekin, M. Serdar,Celik, Murat
, p. 10 - 11 (2007/10/03)
4-Hydroxy-4-methylcyclohex-2-en-1-one was synthesised from 4-methylanisole. The key step is the regioselective reaction of singlet oxygen with 4-methylcyclohex-3-en-1-one.
Synthesis Based on Cyclohexadienes. V. A New Approach to the Synthesis of A-Ring Aromatic Steroids: a Formal Total Synthesis of (+/-)-Estrone
Rao, G. S. R. Subba,Banerjee, D. K.,Devi, L. Uma,Sheriff, Uma
, p. 187 - 203 (2007/10/02)
A new strategy for the construction of A-ring aromatic steroids which resulted in the formal total synthesis of estrone is described.Thus reaction of the adduct (9), obtained from 1-methoxy-4-methylcyclohexa-1,4-diene and acrolein, with 3-(m-methoxyphenyl
Cyclopentannulation reactions with organoiron reagents. facile construction of functionalized hydroazulenes
Rosenblum,Watkins
, p. 6316 - 6322 (2007/10/02)
Troponeiron tricarbonyl, 2-methyltroponeiron tricarbonyl, and 4-methyltroponeiron tricarbonyl are converted to fluxional tropyliumiron tricarbonyl salts by treatment with either trimethylsilyl or di-n-butylboron triflate. These pentadienyliron cations react with (η1-allyl) (η1-propargyl)-, and (η1-allenyl)Fp complexes [Fp = C5H5Fe(CO)2] to give ketohydroazulene cycloadducts derived, in each reaction, from a single tautomeric tropylium cation. The further reaction of two such cycloadducts 14 and 22b with lithium dimethyl cuprate gave tricyclic ketones 25a and b, through a sequence depicted as involving initial formation of an anionic acyliron complex, followed by migratory insertion and an intramolecular aldol condensation.
Synthesis of 3-Ethenyl-4-methyl-cyclohex-2-en-1-one from 4-Methylanisole
Burge, Geoffrey L.,Collins, David J.,Reitze, John D.
, p. 1913 - 1925 (2007/10/02)
Epoxidation of 8-methyl-1,4-dioxaspirodec-7-ene (13) with peroxybenzoic acid afforded 6'-methylspirooxabicycloheptane> (12), isomerization of which with a catalytic amount of lithium perchlorate in refluxing benzene yield
Tricyclo2,8>octan-3-one: Photochemisch hergestellte Bausteine zur enantiospezifischen Totalsynthese cyclopentanoider Naturstoffe
Demuth, Martin,Schaffner, Kurt
, p. 809 - 825 (2007/10/02)
Bi- und tricyclopentanoide Naturstoffe stehen seit einigen Jahren als Zielstrukturen im Vordergrund des Interesses praeparativ arbeitender Chemiker.Mangels abwandelbarer Synthesemethoden wurden bisher meist nur produktbezogene Einzelloesungen erreicht, wobei in der Regel racemische Endstufen erhalten wurden.Das hier vorgestellte neue Konzept geht von einem einfachen Grundbaustein, dem Tricyclo2,8>octan-3-on, aus und erschliesst erstmals einen enantiospezifischen Zugang zu verschiedenen cyclopentanoiden Verbindungen.Das Tricyclooctanon ist in hoher Ausbeute aus Benzol erhaeltlich; dabei ist die Triplett-sensibilisierte Oxa-di-$ p-methan-Umlagerung von Bicyclooctenon die photochemische Schluesselreaktion.Racematspaltungen koennen problemlos auf der Bicyclooctenon-Stufe vorgenommen werden.Die strukturellen Eigenschaften des Tricyclooctanons erfuellen die Anforderungen an einen zentralen Synthesebaustein: Isomerisierungs- und Aufbaureaktionen lassen sich in hohen Ausbeuten regio- und stereoselektiv ausfuehren.Erste abgeschlossene Anwendungsbeispiele, Totalsynthesen von Boschnialacton, Allodolicholacton, Irido- und Isoridomyrmecin sowie von O-Acetyl-loganinaglucon, und erfolgversprechende Ansaetze zur Synthese von Coriolin, von 6a-Carbaprostacyclin und Homologen sowie von 9,11-Dehydrooestron demonstrieren das einzigartige Synthesepotential des Tricyclooctanons fuer Totalsynthesen polycyclopentanoider Verbindungen.
