Fernando López

• Spanish National Research Council

Carbonyl‐tethered alkylidenecyclopropanes can react with aryl isocyanates in presence of Pd(0)‐phosphoramidite catalysts to give seven‐membered heterobicyclic products in a formal [3+2+2] cycloaddition process. The reaction involves the formation of a palladium p‐allyl complex intermediate (A), which behaves as a formal 1,5‐dipole, and can be trapp...

The combination of a Pd(0) source and a phosphoramidite ligand promotes a formal allylic cross‐coupling between alkylidenecyclopropanes (ACPs) and boronic acids to yield synthetically appealing 1,1‐disubstituted alkenes. Remarkably, the reaction proceeds both under neutral and basic conditions, and works with both aryl‐ and alkenylboronic acids. DF...

The direct auration of arenes is a key step in numerous gold‐catalyzed reactions. Although reported more than 100 years ago, understanding of its underlying mechanism has been hampered by the difficulties in the isolation of relevant intermediates given the propensity of gold(III) species to undergo reductive elimination. Here, we report the synthe...

Pyrroles and indoles bearing N‐allenyl tethers participate in a variety of iridium‐catalyzed cycloisomerization processes initiated by a C−H activation step, to deliver a diversity of synthetically relevant azaheterocyclic products. By appropriate selection of the ancillary ligand and the substitution pattern of the allene, the reactions can diverg...

Low-valent cobalt complexes can promote intramolecular (3 + 2) cycloadditions of alkyne-tethered cyclopropenes to provide bicyclic systems containing highly substituted cyclopentadienyl moieties with electronically diverse functional groups. The adducts can be easily transformed into new types of CpRh(III) and CpIr(III) complexes, which show cataly...

Pyrroles and indoles bearing N‐allenyl tethers participate in a variety of iridium‐catalyzed cycloisomerization processes initiated by a C‐H activation step, to deliver a diversity of synthetically relevant azaheterocyclic products. By appropriate selection of the ancillary ligand and the substitution pattern of the allene, the reactions can diverg...

The direct auration of arenes is a key step in numerous gold‐catalyzed reactions. Although reported more than 100 years ago, understanding of its underlying mechanism has been hampered by the difficulties in the isolation of relevant intermediates given the propensity of gold(III) species to undergo reductive elimination. Here, we report the synthe...

Low‐valent cobalt complexes equipped with phosphorous type of ligands can promote the intramolecular (3+2) cycloaddition of alkylidenecyclopropanes (ACPs) with alkenes and with allenes. Dienes can also be used as partners, but they afford seven‐membered cycloadducts. The reactions are fully diastereoselective and, in some cases, we also observed mo...

Cobalt(I) catalysts equipped with bisphosphine ligands can be used to promote formal (3 + 2 + 2) intramolecular cycloadditions of enynylidenecyclopropanes of type 1. The method provides synthetically appealing 5,7,5-fused tricyclic systems in good yields and with complete diastereo- and chemoselectivity. Interestingly, its scope differs from that o...

Cationic cyclopentadienyl Ru(ii) catalysts can efficiently promote mild intermolecular alkyne-alkene couplings in aqueous media, even in the presence of different biomolecular components, and in complex media like DMEM. The method can also be used for the derivatization of amino acids and peptides, therefore proposing a new way to label biomolecule...

p class="Helv‐Abstract" style="margin: 6pt 0cm; text‐align: justify; line‐height: 16px; font‐size: 8pt; font‐family: "Myriad Pro", sans‐serif; caret‐color: rgb(0, 0, 0); color: rgb(0, 0, 0);"> Recent years have witnessed a considerable progress in research aimed at merging transition metal catalysis with chemical and cell biology. Therefore, a cres...

Pd⁰ catalysts featuring phosphorus‐based monodentate ligands can detour the reactivity of carbonyl‐tethered alkylidenecyclopropanes (ACPs) from standard (3+2) cycloadditions towards tandem cycloisomerization/cross‐coupling processes. This new reactivity lies on the formation of key π‐allyl oxapalladacyclic intermediates, which are subsequently trap...

Pd(0) catalysts featuring phosphorous‐based monodentate ligands can detour the reactivity of carbonyl‐tethered alkylidenecyclopropanes (ACPs) from standard (3+2) cycloadditions towards tandem cycloisomerization / cross‐coupling processes. This new reactivity lies on the formation of key π‐allyl oxapalladacyclic intermediates, which are subsequently...

We describe a microporous plasmonic nanoreactor to carry out designed near-infrared (NIR)-driven photothermal cyclizations inside living cells. As a proof of concept, we chose an intramolecular cyclization that is based on the nucleophilic attack of a pyridine onto an electrophilic carbon, a process that requires high activation energies and is typ...

We report a versatile, highly enantioselective intramolecular hydrocarbonation reaction that provides a direct access to heteropolycyclic systems bearing chiral quaternary carbon stereocenters. The method, which relies on an iridium(I)/bisphosphine chiral catalyst, is particularly efficient for the synthesis of five‐, six‐ and seven‐membered fused...

Tailored ruthenium sandwich complexes bearing photoresponsive arene ligands can efficiently promote azide–thioalkyne cycloaddition (RuAtAC) when irradiated with UV light. The reactions can be performed in a bioorthogonal manner in aqueous mixtures containing biological components. The strategy can also be applied for the selective modification of b...

We report an enantioselective Ir-catalyzed hydrocarbonation towards pyrrole and indole polycyclic scaffolds featuring five-, six- or seven-membered rings, with tertiary and all-carbon quaternary stereocenters. The process can be coupled with the desymmetrization of prochiral centers to obtain pyrrole- and indole-fused scaffolds with either vicinal...

Tailored cationic RuII complexes are highly effective precatalysts for ruthenium-catalyzed azide–thioalkyne cycloaddition (see scheme). These reactions can now be carried out under very dilute conditions and in complex biorelevant media; they are also compatible with and mutually orthogonal to CuAAC. Moreover, ruthenium–arene sandwich complexes fun...

Low‐valent cobalt complexes equipped with chiral ligands can efficiently promote highly enantioselective (3+2) cycloadditions of alkyne‐tethered alkylidenecyclopropanes. The annulation allows to assemble bicyclic systems containing five‐membered rings in good yields and with excellent enantiomeric ratios. We also present a mechanistic discussion ba...

For years it has been considered that transition metal catalysis was incompatible with water, and even less with biologically relevant aqueous environments. However, an increasing number of reports are demonstrating the viability of achieving organometallic reactions in such media, and even in live cells. Most of these reactions consists of deprote...

The first enantioselective cycloaddition of alkylidenecyclopropanes (ACPs) promoted by an earth‐abundant metal is described. A chiral low‐valent CoI complex generated in situ from a CoII precursor, catalyzes an intramolecular (3+2) cycloaddition between ACPs and alkynes, to give fused bicyclic products in good yields and with excellent er values....

During the last decade, there has been a tremendous interest for developing non‐natural biocompatible transformations in biologically relevant media. Among the different encountered strategies, the use of transition metal complexes offers unique possibilities due to their high transformative power. However, translating the potential of metal cataly...

Major current challenges in nano-biotechnology and nano-biomedicine include the implementation of predesigned chemical reactions in biological environments. In this context, heterogeneous catalysis is emerging as a promising approach to extend the richness of organic chemistry onto the complex environments inherent to living systems. Herein we repo...

Transition metal-catalyzed hydrocarbonations of unsaturated substrates have emerged as powerful synthetic tools for increasing molecular complexity in an atom-economical manner. Although this field was traditionally dominated by low valent rhodium and ruthenium catalysts, in recent years, there have been many reports based on the use of iridium com...

Pyridine‐substituted alkylidenecyclopropanes (Py‐ACPs) react with Au(III) salts through an unprecedented, proximal ring‐opening path, to generate catalytically active pyridine alkenyl [C^N]‐gold(III) species. Mechanistic studies reveal that the activation of the C−C bond of the ACP takes place via a concerted, σ‐bond metathesis type process under v...

Pyridine‐substituted alkylidenecyclopropanes (Py‐ACPs) react with Au(III) salts through an unprecedented, proximal ring‐opening path, to generate catalytically active pyridine alkenyl [C^N]‐gold(III) species. Mechanistic studies reveal that the activation of the C−C bond in the cyclopropyl ring takes place via a concerted, σ‐bond metathesis type‐pr...

A Pd catalyst made from a Pd(0) source and a bulky biaryl phosphine ligand promotes highly efficient intramolecular (3 + 2) heterocycloadditions between alkylidenecyclopropanes (ACPs) and carbonyls. The annulations provide a straightfor-ward access to fused polycyclic systems featuring β-methylene tetrahydrofuran moieties. DFT data support a pallad...

Translating the potential of transition metal catalysis to biological and living environments promises to have a profound impact in chemical biology and biomedicine. A major challenge in the field is the creation of metal-based catalysts that remain active over time. Here, we demonstrate that embedding a reactive metallic core within a microporous...

We describe the discovery of unprecedented annulation processes of 1,7-allenedienes, promoted by Pt or Au catalysts. These transformations allowed to unveil mechanistic pathways that had not been previously observed in reactions involving carbophilic catalysis. In particular, we have found that allenedienes bearing a silyl ether at the carbon tethe...

Cycloaddition reactions, by involving the formation of at least two bonds and one cycle in a single operation, represent one of the more practical ways to assemble carbo- and heterocyclic structures from simple acyclic precursors. Especially appealing are formal cycloadditions promoted by transition metals, owing to the ability of these reagents to...

We describe the fabrication of hollow microspheres consisting of mesoporous silica nanoshells decorated with an inner layer of palladium nanoparticles, and their use as Pd-nanoreactors in aqueous media. These palladium-equipped capsules can be used to promote the uncaging of propargyl-protected phenols, as well as Suzuki-Miyaura cross-couplings, in...

Piperidine scaffolds are present in a wide range of bioactive natural products, and are therefore considered as highly valuable, privileged synthetic targets. In this manuscript, we describe a gold-catalyzed annulation strategy that allows a straightforward assembly of piperidines and piperidine-containing aza-bridged products from readily availabl...

We report an Ir(I)-catalyzed cycloisomerization methodology that provides access to carbocyclic systems bearing exo-alkene moieties from alkynyl-equipped acyclic precursors. The method relies on the C-H activation of olefinic and (het-ero)aromatic C(sp2)–H bonds, followed by an exo-cyclization to a tethered alkyne, and provides interesting cyclic d...

We report a highly enantioselective [3C + 2C] intramolecular cycloadditions of alkylidenecyclopropanes (ACPs) and alkenes. The best results are obtained by using sterically demanding chiral phosphoramidite ligands derived from Vapol. Moreover, we also show that related, but less bulky phosphoramidites can also lead to very effective [4C + 3C] cyclo...

The viability of building artificial metabolic pathways within a cell will depend on our ability to design biocompatible and orthogonal catalysts capable of achieving non-natural transformations. In this context, transition metal complexes offer unique possibilities to develop catalytic reactions that do not occur in nature. However, translating th...

The development of efficient metal-promoted bioorthogonal ligations remains as a major scientific challenge. Herein we demonstrate that azides undergo efficient and regioselective room temperature annulations with thioalkynes in aqueous milieu, when treated with catalytic amounts of a suitable ruthenium complex. The reaction is compatible with diff...

The development of efficient metal-promoted bioorthogonal ligations remains as a major scientific challenge. Herein we demonstrate that azides undergo efficient and regioselective room temperature annulations with thioalkynes in aqueous milieu, when treated with catalytic amounts of a suitable ruthenium complex. The reaction is compatible with diff...

A catalytic, versatile and atom-economical C-H functionalization process that provides a wide variety of cyclic systems featuring methyl-substituted quaternary stereocenters is described. The method relies on the use of a cationic Ir(I)-bisphosphine catalyst, which promotes a carboxamide-assisted activation of an olefinic C(sp2)-H bond followed by...

A straightforward and atom-economical enantioselective approach to highly substituted tetrahydropyrans is reported. The process, which consists of an intermolecular gold-catalyzed [2+2+2] cycloaddition between allenamides, alkenes, and aldehydes, is efficiently catalyzed by both phosphoramidite- and chiral N-heterocyclic carbene-gold catalysts, occ...

A practical synthesis of (−)-englerin A was accomplished in 17 steps and 11 % global yield from commercially available achiral precursors. The key step consists of a platinum-catalyzed [4C+3C] allenediene cycloaddition that directly delivers the trans-fused guaiane skeleton with complete diastereoselectivity. The high enantioselectivity (99 % ee) s...

A practical synthesis of (−)-englerin A was accomplished in 17 steps and 11 % global yield from commercially available achiral precursors. The key step consists of a platinum-catalyzed [4C+3C] allenediene cycloaddition that directly delivers the trans-fused guaiane skeleton with complete diastereoselectivity. The high enantioselectivity (99 % ee) s...

During the last decade, there has been an impressive amount of new reactions catalyzed by gold (I or III) complexes, many of which lead to oxygen heterocycles in novel, practical, and efficient ways. In this chapter we have selected the most representative examples of the use of gold catalysis for the synthesis of oxygenated heterocycles, with an o...

Allenamides participate as two-carbon components in an intermolecular [2+2+2] cycloaddition with alkenes and aldehydes when treated with catalytic amounts of a phosphite gold complex. The reaction is highly regio- and chemoselective, and works with different types of alkenes, including styrenes, enol ethers or enamides, as well as with aromatic and...

α,β-Unsaturated N,N-dialkyl hydrazones undergo a mild [2 + 2] cycloaddition to allenamides when treated with a suitable gold catalyst. The method, which represents the first application of N,N-dialkyl hydrazones in gold catalysis, is compatible with a wide variety of substituents at the alkenyl moiety of the hydrazone component, proceeds with excel...

A highly diastereo- and chemoselective intramolecular nickel-catalyzed cycloaddition of alkene- and alkyne-tethered alkynylidenecyclopropanes is reported. The method constitutes the first fully intramolecular [3 + 2 + 2] alkylidenecyclopropropane cycloaddition occurring via a proximal cleavage of the cyclopropane and makes it possible to build rele...

A Rh-catalyzed intramolecular [3+2+2] cycloaddition is reported. The cycloaddition affords synthetically relevant 5,7,5-fused tricyclic systems of type 2 from readily available dienyne precursors. The transformation takes place with moderate or good yields, high diastereoselectivity, and total chemoselectivity.

This feature review describes the development of catalytic [4+2] and [4+3] cycloadditions of allenes, as efficient and practical methodologies for assembling six and seven-membered cyclic systems. The different methodologies have been classified depending on the type of key reactive intermediate that was proposed in the catalytic cycle.

The mechanism of the gold-catalyzed intermolecular cycloaddition between allenamides and 1,3-dienes has been explored by means of a combined experimental and computational approach. The formation of the major [4+2] cycloaddition products can be explained by invoking different pathways, the preferred ones being determined by the nature of the diene...

In recent years there have been extraordinary developments of gold(I)-catalyzed enantioselective processes. This includes progress in the area of cycloaddition reactions, which are of particular interest due to their potential for the rapid construction of optically active cyclic products. In this article we will summarize some of the most remarkab...

The complex [OsCp{kappa(3)-P,C,C-(PPr2)-Pr-i[C-(CH3)=CH2]}(CH3CN)]PF6 (1) reacts with (2-pyridyl)-methylenecyclopropane, at room temperature, to give initially the cyclobutylidene derivative [Os(eta(5)-C5H5)-(=CCH2CH2CH-o-C5H4N){(PPr2)-Pr-i[C(Me)=CH2]}]PF6 (2), as a result of the ring expansion of the alkylidenecyclopropane unit. Over time complex...

Gold standard: Allenamides react with aldehydes or ketones having γ, δ, or ε alkenyl groups, upon activation with suitable gold catalysts, to provide oxa-bridged systems containing seven- to nine-membered carbocycles, in a formal cascade cycloaddition. By using chiral phosphoramidite/gold or bisphosphine/gold catalysts it is possible to obtain the...

The cycloaddition of allenamide (I) to alkenes represents a simple and practical access to highly substituted cyclobutane derivatives and proceeds with high regioselectivity.

The first highly enantioselective intermolecular (4 + 2) cycloaddition between allenes and dienes is reported. The reaction provides good yields of optically active cyclohexenes featuring diverse substitution patterns and up to three stereocenters. Key to the success of the process is the use of newly designed axially chiral N-heterocyclic carbene-...

3-(Propa-1,2-dien-1-yl)oxazolidin-2-one works as an efficient two-carbon partner in a variety of intermolecular gold-catalyzed [2+2]?cycloadditions to alkenes. The transformation represents a simple and practical entry to highly substituted cyclobutane derivatives and takes place with complete regio- and stereocontrol.

A practical protocol for the hydroalkynylation of enones using Pd catalysis is reported. The reaction proceeds efficiently with a variety of alkynes as well as with several cyclic and acyclic enones, providing synthetically relevant β-alkynyl ketones in good to excellent yields.

Allene-tethered dienes undergo entitled cycloaddition by treatment with a suitable chiral Au—phosphoramidite catalyst to provide synthetically valuable fused bicyclic systems with high diastereoselectivity and excellent enantioselectivities.

We present a compilation of methodologies developed in our laboratories to assemble polycyclic structures containing small-and medium-sized cycles, relying on the use of transition-metal-catalyzed (TMC) cycloadditions. First, we discuss the use of alkylidene-cyclopropanes (ACPs) as 3C-atom partners, in particular in their Pd-catalyzed (3 + 2) cyclo...

Allene-tethered dienes (1) undergo an intramolecular and highly enantioselective (4+3) cycloaddition when treated with suitable chiral phosphoramidite/gold(I) catalysts (see scheme; Ar=9-anthracenyl). The reactions provide synthetically relevant [5.3.0] and [5.4.0] fused bicyclic systems 2 with good yields, complete diastereocontrol, and excellent...

The previously unnoticed Ru complex activates the title reaction which proceeds under mild conditions and is fully diastereoselective.

The intramolecular [4C+3C] cycloaddition reaction of allenedienes catalysed by PtCl(2) and several Au(I) complexes has been studied by means of DFT calculations. Overall, the reaction mechanism comprises three main steps: (i) the formation of a metal allyl cation intermediate, (ii) a [4C(4π)+3C(2π)] cycloaddition that produces a seven-membered ring...

In the last years there have been extraordinary advances in the development of gold-catalyzed cycloaddition processes. In this review we will summarize some of the most remarkable examples, and present the mechanistic rational underlying the transformations.

A variety of polysubstituted cyclohexene derivatives, e.g. (III), (VII), (IX) or (XI), is prepared by highly regio- and diastereoselective Au(I)-catalyzed [4 + 2] cycloaddition of allenamides with acyclic dienes.

We report a ruthenium-catalyzed (2 + 2) intramolecular cycloaddition of allenes and alkenes. We have found that the use of the ruthenium complex RuH(2)Cl(2)(P(i)Pr(3))(2), which has previously gone unnoticed in catalytic applications, is crucial for the observed reactivity. The reaction proceeds under mild conditions and is fully diastereoselective...

Allenes are very versatile synthetic units that are used in many types of catalytic cycloaddition reactions. Most examples reported so far involve their use as 2C-atom components, whereas their participations as 3C-atom components have been much less frequent. In this concept article, we present an overview of this latter strategy, emphasizing on t...

A new type of intermolecular (4 + 2) cycloaddition, based on a gold-catalyzed reaction between allenamides and acyclic conjugated dienes, is reported. The annulation, which fails under standard Diels–Alder conditions, provides a straight entry to a variety of differently substituted cyclohexenes, and takes place with excellent regio- and diastereos...

Allenes, owing to their special structural characteristics related to the presence of two π bonds in a formally strained manner, are particularly prone to undergo gold-activated reactions, particularly cycloaddition processes. Theoretical studies based on DFT calculations have been very useful to explain observed reactivities and advance mechanisti...

Jetzt auch mit Nickel: Nickelkatalysierte [3C+2C+2C]-Cycloadditionen unter Beteiligung nichtaktivierter Alkylidencyclopropane öffnen einen Zugang zu vielfältigen kondensierten 6,7-Bicyclen (siehe Schema; cod=1,5-Cyclooctadien). Dichtefunktionalrechnungen und experimentelle Daten sprechen für einen Katalysezyklus, der mit der Bildung von 1-Alkyliden...

Contrary to previous palladium- or rhodium-catalyzed cycloadditions of alkynylidenecyclopropanes, which result in the formation of cycloadducts arising from the distal opening of the cyclopropane, the current method gives complementary 6,7-fused bicyclic systems resulting from cleavage of the proximal bond of the ring.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Introduction of a homochiral p-tolylsulfinyl group at an appropriate position in the alkene accelerates the thermal [5C + 2C] intramolecular cycloaddition to β-silyloxy-γ-pyrones and, most importantly, leads to excellent levels of diastereodifferentiation. The resulting adducts can be easily desulfinylated to give optically active 8-oxabicyclic[3.2...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

We report a Pd-catalyzed intramolecular [3C + 2C + 2C] cycloaddition between alkylidenecyclopropanes, alkynes and alkenes. The method provides synthetically relevant 5-7-5 tricyclic structures, with good chemoselectivity and complete diastereoselectivity.

The reactions of (2-pyridyl)methylenecyclobutane with the metal fragments [OsTp(PiPr3)]+ and [OsCp(PiPr3)]+ (Tp = hydridotris(pyrazolyl)borate, Cp = cyclopentadienyl) are shown. Complex [OsTp(κ1-OCMe2)2(PiPr3)]BF4 (1) reacts with the organic substrate to give [OsTp{η2-C(CH2CH2CH2)═CH-C5H4N}(PiPr3)]BF4 (2), which evolves into the cyclopentylidene de...

The reactivity of the dihydrides MH2Cl2(PiPr3)2 (M = Os (1), Ru (2)) toward allenes has been studied. Complex 1 reacts with 2 equiv of 3-methyl-1,2-butadiene and 1-methyl-1-(trimethylsilyl)allene to give 1 equiv of olefin and the π-allene derivatives OsCl2(η2-CH2═C═CRMe)(PiPr3)2 (R = Me (3), Me3Si (4)). The X-ray structure of 4 proves the coordinat...

We report a Pd-catalyzed intramolecular [3C + 2C + 2C] cycloaddition between alkylidenecyclopropanes, alkynes and alkenes. The method provides synthetically relevant 5-7-5 tricyclic structures, with good chemoselectivity and complete diastereoselectivity.

Introduction Enantioselective Conjugate Addition to Cyclic Enones Enantioselective Conjugate Addition to Acyclic Enones Enantioselective Conjugate Addition to α,β‐Unsaturated Esters and Thioesters Application of the Conjugate Addition of Grignard Reagents to α,β‐Unsaturated Thioesters in the Synthesis of Natural Products Mechanistic Studies E...

The complex [OsTp(kappa(1)-OCMe)(2)(P(i)Pr(3))]BF(4) [Tp = hydridotris(pyrazolyl)borate] promotes the cleavage of both C(sp(3))-C(sp(2)) bonds of benzylidenecyclopropane and 3-phenylpropylidenecyclopropane to yield the complexes [OsTp(=C=CHR)(eta(2)-CH(2)=CH(2))(P(i)Pr(3))]BF(4) (R = Ph, CH(2)CH(2)Ph). The process is proposed to take place via meta...

Halogen-free CC coupling: Catalytic amounts of [Pd2(dba)3] (dba=dibenzylideneacetone) and a sterically encumbered phosphite (L1) promote the addition of CH bonds of terminal alkynes (2) to alkylidenecyclopropanes (1). The reaction gives rise to 1,4-enynes (3) in good yields. The catalytic cycle probably consists of a Pd-catalyzed CH activation of t...

Alkylidenecyclopropanes containing a chelation assistant at the terminal carbon atom of the olefinic moiety undergo an Os- or Ru-promoted ring expansion reaction to afford metal cyclobutylidene derivatives. The process occurs through a novel mechanism that implies a 1,2-migration of a CH(2) group of the three-membered ring from an olefinic carbon a...

Gold(I) complexes featuring electron acceptor ligands such as phosphites and phosphoramidites catalyze the [4C+2C] intramolecular cycloaddition of allenedienes. The reaction is chemo- and stereoselective, and provides trans-fused bicyclic cycloadducts in good yields. Moreover, using novel chiral phosphoramidite-based gold catalysts it is possible t...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An experiment was conducted to discover that Au complex generated in situ from [(IPr)AuCl] and AgSbF6 catalyzes the [4C+3C] intramolecular cycloaddition of a variety of allenedienes at room temperature. Allenediene was treated with 10 mol% of AuCl3 or AuCl, the desired [4C+3C] cycloadduct was obtained in good yield. Screening of other Au catalysts...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

IntroductionEnantioselective Conjugate Addition to Cyclic EnonesEnantioselective Conjugate Addition to Acyclic EnonesEnantioselective Conjugate Addition to α,β-Unsaturated Esters and ThioestersApplication of the Conjugate Addition of Grignard Reagents to α,β-Unsaturated Thioesters in the Synthesis of Natural ProductsMechanistic StudiesEnantioselect...

(Chemical Equation Presented) Crossing the seven C's: The three carbon atoms of several allenyl fragments can be incorporated into seven-membered carbocycles by means of a Pt-catalyzed intramolecular [4C+3C] cycloaddition with dienes (see scheme). The transformation provides a straightforward and atom-economical entry to a variety of cycloheptane-c...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Octa-5,7-dienylidenecyclopropanes undergo [4 + 3] intramolecular cycloaddition reactions upon treatment with appropriate palladium catalysts to give stereochemically rich bicyclo[5.3.0]octane systems in a completely diastereoselective manner.