A conceptually novel pyrrole synthesis is reported, efficiently merging enamines and (unactivated) alkynes under oxidative conditions. In an intermolecular Rh catalyzed process, the challenging allylic sp3 C−H activation of enamine substrates followed by cyclization with alkyne (R3 = CO2R). Alternatively, in some cases CN), can be utilized for a vinylic sp2 activation. total 17 examples yields above 60% presented, together results initial mechanistic investigation.

A good neighborhood! The metal-catalyzed oxidative CH functionalization of electron-rich arenes is well-established, but analogous reactions electron-poor substrates are rare. new application makes use common electron-withdrawing functional groups (COMe, CONH2, CONEt2) in the rhodium-catalyzed Heck reaction to generate complex organic molecules. Cp*= η5-C5Me5. Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed, not copy-edited or...

In the catalyzed oxidative olefination of acetanilides (oxidative-Heck coupling), Rh offers great advantages over more common Pd catalysts. Lower catalyst loadings, large functional group tolerance (in particular to halides), and higher reactivity electron-neutral olefins (styrenes) are some attractive features. Most interestingly, even ethylene reacts yield corresponding acetanilido-styrene. Moreover, CuII oxidant can also be utilized in catalytic amounts with air serving as terminal oxidant.

The synthesis of indenols and fulvenes was achieved through Rh-catalyzed C−H bond activation simple diverse aryl ketone derivatives subsequent coupling with internal alkynes. process found to involve either an α or γ dehydration step, depending on the substrate disposition representing pathways toward functionalized fulvenes.

Come in! The use of internal oxidants, embedded in the directing group, CH activation reactions can lead to higher levels selectivity and reactivity under milder conditions (see examples). An oxidant be defined as a covalent bond within one coupling substrates which oxidizes metal catalyst. This should open up new avenues field activation.

Olefin(s) get-together! A RhIII-catalyzed oxidative cross-coupling of different olefins was developed, resulting in the formation valuable linear butadiene products and especially di-unsaturated α-amino acid derivatives. 1,1-Di-, 1,2-di-, 1,1,2-trisubstituted could be coupled with styrenes acrylates. In these reactions, remarkably high levels chemo-, regio-, stereoselectivity were obtained, rendering this a synthetic tool. Detailed facts importance to specialist readers are published as...

Directed, undirected! Rhodium(III)-catalyzed double CH bond activation (one directed, one undirected) provides an efficient route to biaryls (see scheme; DG=directing group). Significant kinetic isotope effects for both reaction partners and H/D scrambling between them are interesting experimental findings. While the mechanism is still unclear, a rhodium(V) species invoked in catalytic cycle.

Eine gute Nachbarschaft: Während die Metall-katalysierte oxidative C-H-Funktionalisierung von elektronenreichen Arenen bereits etabliert ist, sind analoge Methoden für elektronenarme Substrate noch recht selten. Ein neues Verfahren unter Anwendung gebräuchlichen elektronenziehenden Gruppen (COMe, CONH2, CONEt2) in der Rhodium-katalysierten oxidativen Heck-Reaktion ermöglicht nun den Aufbau komplexer organischer Moleküle (siehe Schema; Cp*=η5-C5Me5, DG=dirigierende Gruppe). Detailed facts of...

Abstract A method was developed for the direct dehydrogenative construction of CN bonds between unprotected phenols and a series cyclic anilines without resorting to any kind metal activation either substrate use halides. The resulting process relies on exclusively organic molecular oxygen subsequent oxidation aniline substrate. This allows coupling ubiquitous phenols, thus furnishing aminophenols through an atom‐economical most sustainable amination method. new reactivity, which intrinsic...

The construction of (hetero)biaryls, which are ubiquitous scaffolds among medical substances, functional materials, and agrochemicals, constitutes a key application cross-coupling methods. However, these usually require multiple synthetic steps. Herein, we report simple photoinduced catalyst-free C–H/C–H (hetero)arylation through aryl thianthrenium salts, formed site-selectively by direct C–H functionalization. to this approach is the UV-light, can disrupt C–S bond form thianthrene radical...

H bonds make the catalysts! A single hydrogen bond between ligands coordinated to a rhodium center is critical for formation of pure supramolecular catalysts asymmetric hydrogenation reactions. The ester group amidite ligand (see scheme) also forms with substrate. Use heterocomplex afforded highest enantioselectivity reported date several substrates.

Sulfonamido−phosphoramidite ligands lead to the formation of Rh−Rh dinuclear complexes through anionic P−N− bridging character. The resulting "boat-shaped" catalysts activate molecular H2 a cooperative endocyclic mechanism, in one and classical hydride on complex. These new are very active hydrogenation that operate via activation as calculated with density functional theory, they display unequaled high selectivities hindered cyclic acetamidoalkenes.

Erase the base: An iridium complex based on a cooperative ligand that functions as an internal base is reported. This can rapidly and cleanly dehydrogenate formic acid in absence of external base, reaction required if to be exploited energy carrier (see scheme).

Effizient zu Biarylen führt eine Rhodium(III)-katalysierte doppelte C-H-Aktivierung, in der ein Schritt dirigiert und andere nichtdirigiert verläuft (siehe Schema; DG = dirigierende Gruppe). Für die beiden Reaktionspartner wurden erhebliche kinetische Isotopeneffekte H-D-Austausch beobachtet. Der Mechanismus dieser ungewöhnlichen Arylierung ist noch nicht geklärt, aber möglicherweise tritt im Katalysezyklus Rhodium(V)-Spezies auf.

A Rh catalyzed, no-chelate-assisted C-H activation/oxidative olefination reaction of bromoarenes has been discovered, in which the latter ones seem to act as a substrate, terminal oxidant, and catalyst modifier.

The cooperative action of Ru and Cu catalysts enables direct polynuclear C–H N–H activation for the dehydrogenative N-carbazolation carbazoles, selectively at C1 position. Initial mechanistic experiments are presented discussed.

Herein! Die Verwendung interner, in der dirigierenden Gruppe eingebauter Oxidantien bei C-H-Aktivierungen kann zu verbesserter Selektivität und Reaktivität unter milderen Reaktionsbedingungen führen (siehe Beispiele). Ein internes Oxidans als kovalente Bindung innerhalb eines Kupplungssubstrate definiert werden, die den Metallkatalysator oxidiert. Dies sollte neue Möglichkeiten auf dem Gebiet C-H-Aktivierung eröffnen.

The dehydrogenative C-N cross-coupling of unprotected, secondary anilines through ortho-N-carbazolation has been achieved using a Ru catalytic system with O2 as the terminal oxidant. reactions proceed in an intermolecular fashion, selectively ortho position. Implications for field organic synthesis are discussed.

Metal-free N-H functionalization reactions represent an important strategy for sustainable C-N coupling reactions. In this report, we describe the visible light photolysis of aryl diazoacetates in presence some N-heterocycles that enables mild, metal-free carbazole and azepine heterocycles (15 examples, up to 83% yield).

Adapt to react: METAMORPhos ligands are a class of flexible and adaptive hydrogen-bonded multidentate sulfonamide-based phosphorus ligands. Selective formation complexes with two different (see scheme) that display unusual kinetic behavior leads the proposal new mechanism. These highly reactive enantioselective in rhodium-catalyzed asymmetric hydrogenation alkenes. Supporting information for this article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z705212_s.pdf or...

Undirected/Directed Cross-Coupling: A new dehydrogenative RhIII-catalyzed cross-coupling reaction between bromoarenes bearing no directing group and vinylic substrates substituted by a chelating is reported. An original mechanism enables the use of internal alkenes in Z-selective coupling. The application 1,3-disubstituted or 1,2-homodisubstituted arenes leads to formation highly functionalized, complex, valuable olefins as one single isomer. Detailed facts importance specialist readers are...

Abstract Phosphorylated sulfonimidamides (SIAPhos) undergo ion exchange reactions with cationic complexes, [Rh(cod) 2 BF 4 ] and [Ir(cod) BarF], or neutral complexes [Rh(cod)Cl] [Ir(cod)Cl] , leading to unprecedented P‐N‐S‐N chelates. Use of the resulting iridium in asymmetric hydrogenation tri‐ tetrasubstituted enamides leads products high enantioselectivities (up 92% ee ).

Abstract A highly selective Cu II ‐catalyzed cross‐dehydrogenative ortho ‐aminomethylation of phenols with aniline derivatives is described. The corresponding C(sp 2 )−C(sp 3 ) coupling products were obtained in moderate to excellent yields under mild reaction conditions and a broad substrate scope. radical mechanism proposed.