Oxocarbon salts (M2 (CO)n ) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed used as electrodes in rechargeable Li, K-ion batteries. The results show that M2 (CO)5 /M2 (CO)6 can insert two or four reversibly, while (CO)4 shows less electrochemical activity. Especially, we discover the K2 C6 O6 electrode enables ultrafast potassium-ion insertion/extraction 212 mA h g(-1) at 0.2 C 164 10 C. This...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTEnantioselective Nazarov Reactions through Catalytic Asymmetric Proton TransferGuangxin Liang and Dirk TraunerView Author Information Center for New Directions in Organic Synthesis, Department of Chemistry, University California, Berkeley, California 94720-1460 Cite this: J. Am. Chem. Soc. 2004, 126, 31, 9544–9545Publication Date (Web):July 17, 2004Publication History Received22 April 2004Published online17 July inissue 1 August...

Expeditious and high-yielding Nazarov cyclizations of 2-alkoxy-1,4-pentadien-3-ones are described. An example a catalytic asymmetric cyclization is presented. [reaction: see text]

A unified approach toward the taiwaniaquinoids that has yielded four natural products is described. new variant of Nazarov reaction with concomitant formation an enol triflate serves as one key steps, considerably shortening synthetic scheme and providing a general entry into this class bioactive products.

Short and sweet: (−)-Isatisine A was constructed using common inexpensive building blocks, such as indole D-ribose (see scheme). The synthesis features an unprecedented intramolecular C glycosylation of oxidative ring contraction. Detailed facts importance to specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by the authors. Please note: publisher is responsible for content functionality any...

Cut to the chase: Direct formation of an enehydrazine, intermediate in classic Fischer indole synthesis, solves regioselectivity problem associated with indolization. This approach not only achieves selective synthesis indoles through proper selection vinyl halide, but also leads quick construction desoxyeseroline and esermethole, as well key structural motif Akuammiline alkaloid vincorine. Detailed facts importance specialist readers are published "Supporting Information". Such documents...

Abstract Oxocarbon salts (M 2 (CO) n ) prepared through one‐pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks ( =4, 5, 6) have been rationally designed used as electrodes in rechargeable Li, K‐ion batteries. The results show that M 5 /M 6 can insert two or four reversibly, while 4 shows less electrochemical activity. Especially, we discover the K C O electrode enables ultrafast potassium‐ion insertion/extraction 212 mA h g −1 at 0.2 164 10 C. This behavior...

A concise asymmetric approach to the indeno-tetrahydropyridine core of unusual alkaloid haouamine B allowed for an investigation a biomimetic oxidative phenol coupling as proposed biosynthetic step, and ultimately provided access published structure natural product. As consequence our synthetic studies, has been revised.

An efficient and scalable synthesis of the ABC ring system common to calyciphylline A-type alkaloids has been developed. The tricyclic core features a bowl-shaped [6-6-5] skeleton with five stereogenic centers including an all-carbon quaternary center. It was constructed rapidly from readily available carvone derivative through seven-step sequence involving aza-Michael addition Pd-catalyzed enolate α-vinylation as key steps.

A concise total synthesis of mersicarpine is achieved by exploiting a cyclic carbamate for generation tertiary carbocation. The key step involves intramolecular Friedel-Crafts alkylation with this carbocation the construction quaternary carbon center and subsequent oxidation cyclization cascade formation seven-membered imine. chemistry allowed rapid one-pot from simple intermediate using straightforward chemical operations.

Selective syntheses of alkaloids bearing distinct core structures were enabled by chemically programmed polycyclizations using water as a switch.

A splice from life: photoinduced rearrangement cascade with alternating photochemical and thermal pericyclic steps leads to a novel pyrone compound chain-contracted polyketide backbone (orinocin (2)). The excision of three propionate units the polyene precursor, spectinabilin (1), proceeds via immunosuppressive SNF4435C/D yields an unusual triketide, mesitylene (see scheme).

This work reports the total syntheses of Isodon diterpenes trichorabdal A and maoecrystal Z via a common bicyclo[3.2.1]octane intermediate, which chemically bridges two distinct structures through retro-aldol/aldol reaction cascade. Other synthetic features include an efficient cross-ring radical cyclization for rapid construction all carbon quaternary center commonly seen in diterpenoids, challenging Ueno-Stork on to sensitive 1,6-enone system, as well serial chemoselective functional group...

Abstract The concise total syntheses of (−)‐indoxamycins A and B is reported. chemistry features a seven‐step preparation highly congested [5.5.6] tricyclic advanced common intermediate from readily available R ‐carvone derivative. Key steps involve Pauson–Khand reaction for the rapid construction basic scaffold bearing quaternary carbon, copper‐catalyzed Michael addition introduction another adjacent all‐carbon stereocenter, tandem retro‐oxa‐Michael addition/1,2‐addition/oxa‐Michael...

A concise and scalable synthesis of a cis-fused bicyclo[5.3.0]decane ring system has been developed for the total echinopines. The core natural products was constructed efficiently through an intramolecular 1,3-dipolar cycloaddition contraction strategy.

A synthetically challenging tetracyclic tertiary amine framework in the Daphniphyllum alkaloid daphenylline was established a six-step sequence featuring an intermolecular Diels–Alder cycloaddition/oxidative aromatization sequence. The utilization of amine–borane complexation strategy is key to successful transformations on our substrates.

Dasabuvir (1) is an HCV polymerase inhibitor which has been developed as a part of three-component direct-acting antiviral combination therapy. During the course development synthetic route, two novel coupling reactions were developed. First, copper-catalyzed uracil with aryl iodides, employing picolinamide 16 ligand, was discovered. Later, palladium-catalyzed sulfonamidation nonaflate 33 developed, promoted by electron-rich palladium complexes, including phosphine VincePhos (50). This made...

Summary of main observation and conclusion Directing strategy has been extensively exploited to maintain activity selectivity for the rapid access functionalized molecules pharmaceutical targets. However, ‘one‐to‐one’ activation model was usually achieved through traditional directing strategy. Herein, we ‘one‐to‐two’ by slight modification simple practical ketoxime amide functionality. With judicious choice groups, Csp 3 —H 2 bond alkynylation reaction, more significantly, dehydrogenative...

Members of a family α-methoxy-γ-pyrone-containing polypropionate natural products have been stereoselectively synthesized. Two key iodovinyl pyrone building blocks were coupled to appropriately selected vinyl stannanes assemble the highly substituted polyene side chains products.

Abstract Total syntheses of two Isodon diterpenes, isorosthin L and isoadenolin I, are reported. The synthetic strategy features a quick assembly simple building blocks through diastereoselective intermolecular aldol reaction subsequent radical cyclization for efficient construction rather complex advanced intermediate bearing quaternary stereocenter present in all diterpenes. Oxidative cleavage the C−C bond cyclopentane enabled conversion to lactone moiety which is desired molecular...

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTStereoselective Syntheses of the Bioactive Polypropionates Aureothin, N-Acetylaureothamine, and AureonitrileGuangxin Liang, Ian B. Seiple, Dirk TraunerView Author Information Department Chemistry, University California, Berkeley, California 94720 Cite this: Org. Lett. 2005, 7, 14, 2837–2839Publication Date (Web):June 9, 2005Publication History Received1 April 2005Revised26 May 2005Published online9 June inissue 1 July...

Eine photoinduzierte Umlagerungskaskade mit alternierenden photochemischen und thermischen pericyclischen Schritten führt zu einer neuen Pyronverbindung einem verkürzten Polyketid-Rückgrat (Orinocin, 2). Das Ausschneiden von drei Propionat-Einheiten aus der Polyen-Vorstufe, Spectinabilin (1), verläuft über die Immunsuppressiva SNF4435C/D ergibt ein ungewöhnliches Polyketid: Mesitylen (siehe Schema). Supporting information for this article is available on the WWW under...