Antonio M. Echavarren

• PhD
• Group Leader at Institute of Chemical Research of Catalonia

A divergent synthesis of three members of the daucane family of natural products is reported, enabled by a gold(I)-catalyzed cycloisomerization/formal (4 + 3) cycloaddition as the key step. The synthesis of penigrisacid A features a vanadium-catalyzed tandem epoxidation/SN2′ cyclization, whereas a Suárez radical cyclization enables the synthesis of...

Oxygen doped analogues of higher acenes have been synthesized on Au(111) through the combination of solution chemistry and on-surface synthesis. On the basis of combined bond-resolved scanning tunneling microscopy (BR-STM), scanning tunneling spectroscopy (STS) and density functional theory (DFT) calculations two isomers containing heptacene core w...

The concise modular synthesis of a family of monodentate 1,2-disubstituted ferrocene ligands containing a diaryl phosphine and a 2-aryl indole is described. Their gold(I) complexes were applied to the enantioselective gold(I)-catalyzed formal [4 + 2] cycloaddition of 1,6-arylenynes, the enyne cyclization/nucleophile addition of N-tethered 1,6-enyne...

Acenes, the group of polycyclic aromatic hydrocarbons (PAHs) with linearly fused benzene rings, possess distinctive electronic properties with potential applicability in material science. Hexacene was the largest acene obtained and characterized in the last century, followed by heptacene in 2006. Since then, a race for obtaining the largest acene r...

Acetylene has been underexploited despite being a highly valuable feedstock for chemical synthesis. We have developed the first true gold(I)-catalyzed intermolecular three-component reaction between acetylene, alkenes, and alcohols to afford β-vinyl hemiaminal scaffolds from N-vinyl amides. Unusual biscyclopropyl and 3-vinyl N-heterocyclic scaffold...

The character of the electronic structure of acenes has been the subject of longstanding discussion. However, convincing experimental evidence of their open‐shell character has so far been missing. Here, we present the on‐surface synthesis of tridecacene molecules by thermal annealing of octahydrotridecacene on a Au(111) surface. We characterized t...

The character of the electronic structure of acenes has been the subject of longstanding discussion. However, convincing experimental evidence of their open‐shell character has so far been missing. Here, we present the on‐surface synthesis of tridecacene molecule by thermal annealing of octahydrotridecacene on Au(111) surface. We characterized the...

Dithienoacenes with a heptacene core, heptaceno[2,3- b :11,12- b ′]bis[1]benzothiophene, have been synthesized through the combination of solution and surface assisted chemistry.

We identify the dominant structures of the intermediates of gold(I)‐catalyzed cyclizations of 1,5‐enynes and 1,5‐allenenes through computational analysis as gold(I) cyclopropylcarbenes, endocyclic vinylgold complexes and previously unreported non‐classical carbocationic minima. In contrast to 1,6‐enynes, the exocyclic carbocations are found to be l...

Two different classes of stereoselective cyclizations have been developed using a chiral auxiliary approach with commercially available [JohnPhosAu(MeCN)SbF6] as catalyst. First, a stereoselective cascade cyclization of 1,5‐enynes was achieved using the Oppolzer camphorsultam as chiral auxiliary. In this case, a one‐pot cyclization‐hydrolysis seque...

Two different classes of stereoselective cyclizations have been developed using a chiral auxiliary approach with commercially available [JohnPhosAu(MeCN)SbF 6 ] as catalyst. First, a stereoselective cascade cyclization of 1,5‐enynes was achieved using the Oppolzer camphorsultam as chiral auxiliary. In this case, a one‐pot cyclization‐hydrolysis seq...

We identify the factors that rule the selectivity in single-cleavage skeletal rearrangements promoted by gold(I) catalysts. We find that stereoconvergence is enabled by a rotational equilibrium when electron-rich substituents are used. The anomalous Z-selective skeletal rearrangement is found to be due to electronic factors, whereas endo-selectivit...

Acetylene gas is an important feedstock for chemical production, although it is underutilized in organic synthesis. We have developed an intermolecular gold(I)-catalyzed alkyne/alkene reaction of o-allylphenols with acetylene gas that gives rise to chromanes by a stereospecific aryloxycyclization through the nucleophilic regioselective opening of c...

The enantioselective reaction of 1,6-enynes with O-, N-, and C-nucleophiles has been developed by matched ion pair gold(I) catalysis in which the chiral gold(I) cation and anion are H-bonded through a urea group. Very high levels of enantiocontrol are achieved (up to >99:1 er) for a broad scope of substrates. DFT studies demonstrate the importance...

The character of the electronic structure of acenes has been the subject of the longstanding discussion. However, convincing experimental evidence of their open-shell character has so far been missing. Here, we present on surface synthesis of tridecacene molecule by thermal annealing of octahydrotridecacene on Au(111) surface. We characterized the...

A new generation of chiral gold(I) catalysts based on variations of complexes with JohnPhos-type ligands with a remote C2-symmetric 2,5-diarylpyrrolidine have been synthesized with different substitutions at the top and bottom aryl rings: from replacing the phosphine by a N-heterocyclic carbene (NHC) to increasing the steric hindrance with bis- or...

A new generation of chiral gold(I) catalysts based on variations of complexes with JohnPhos-type ligands with a remote C2-symmetric 2,5-diarylpyrrolidine have been synthesized with different substitutions at the top and bottom aryl rings: from replacing the phosphine by a N-heterocyclic carbene (NHC), to increasing the steric hindrance with bis- or...

The introduction of alkyne scaffolds in organic molecules is an interesting topic for researchers ranging from synthetic organic chemists to materials scientists. This goal can be achieved through very diverse disconnections strategies, among which the direct alkynylation of CH bonds is particularly appealing due to the broad scope of substrates t...

The Front Cover illustrates the ability of the squaramide group to remove a chiral anionic ligand from Au(I) by H‐bonding interactions, by analogy with a magnet that attracts a metallic sphere. H‐bonded counterion‐directed catalysis was used to perform an enantioselective tandem cycloisomerization‐nucleophile addition to 2‐alkynyl enones. More info...

H‐bonded counterion‐directed catalysis (HCDC) is a strategy wherein a chiral anion that is hydrogen‐bonded to the achiral ligand of a metal complex is responsible for enantioinduction. In this article we present the application of H‐bonded counterion‐directed catalysis to the Au(I)‐catalyzed enantioselective tandem cycloisomerization‐addition react...

Formveränderliche Moleküle wurden in der Gasphase untersucht, wobei die von José L. Alonso und Mitarbeitern in ihrer Mitteilung (DOI: 10.1002/ange.202117045) beschriebenen Phänomene der Valenztautomerie für ein archetypisches Barbaralon schlüssig aufgedeckt werden konnten. Die beiden Valenztautomere dieses bistabilen molekularen Systems wurden zum...

Shape‐shifting molecules were probed in the gas phase, which conclusively unveiled the valence tautomerism phenomena for an archetypal barbaralone as described by José L. Alonso et al. in their Communication (e202117045). The two valence tautomers of this bistable molecular system were isolated in a supersonic jet for the first time and characteriz...

We report a state‐of‐the‐art spectroscopic study of an archetypical barbaralone, conclusively revealing the valence tautomerism phenomena for this bistable molecular system. The two distinct 1‐ and 5‐substituted valence tautomers have been isolated in a supersonic expansion for the first time and successfully characterized by high‐resolution rotati...

This chapter describes the most recent advances made in the field of generation of metal carbenes by retro-Buchner reaction and other related decarbenation processes. Over the past 10 years, this strategy has been established as a powerful alternative for accessing these highly reactive and versatile intermediates, leading to the development of man...

This review covers the progress made in enantioselective cyclizations and cycloadditions catalyzed by gold(I) complexes bearing chiral ligands. Recent examples of enantioselective reactions catalyzed by square-planar Au(III) complexes are also discussed.

Cyclobuta[1,2-b:3,4-b']ditetracene - an analogue of nonacene with a cyclobutadiene unit embedded in the central part has been synthesized by the combination of solution and on-surface chemistry. The atomic structure and electronic properties of the product on Au(111) have been determined by high resolution scanning tunnelling microscopy/spectroscop...

Planar chiral monodentate 1,3-disubstituted ferrocene phosphines inspired on JohnPhos-type ligands have been synthesized and applied to the enantioselective gold(I) catalyzed [4 + 2] cycloaddition of 1,6-arylenynes. Computational studies rationalized the working mode of the catalyst on the folding of the substrate in the chiral environment of the l...

We report a state‐of‐the‐art spectroscopic study of an archetypical barbaralone, conclusively revealing the valence tautomerism phenomena for this bistable molecular system. The two distinct 1‐ and 5‐substituted valence tautomers have been isolated in a supersonic expansion for the first time and successfully characterized by high‐resolution rotati...

A new strategy for enantioselective transition-metal catalysis is presented, wherein a H-bond donor placed on the ligand of a cationic complex allows precise positioning of the chiral counteranion responsible for asymmetric induction. The successful implementation of this paradigm is demonstrated in 5-exo-dig and 6-endo-dig cyclizations of 1,6-enyn...

The ortho-alkynylation of nitro-(hetero)arenes takes place in the presence of a Rh(III) catalyst to deliver a wide variety of alkynylated nitroarenes regioselectively. These interesting products could be further derivatized by...

Starting from a long aza-starphene neutral and nonmagnetic organic molecule, a single-molecule magnet is on-surface constructed using up to 3 light nonmagnetic aluminum (Al) atoms. Seldom observed in solution with transition-metal atoms and going from 1 to 3 Al coordinated atoms, the doublet-singlet-doublet transition is easily on-surface accessibl...

Gold(I) catalysts are ideal for the activation of alkynes under very mild conditions. However, unlike allenes or alkenes, the triple bond of alkynes cannot be prochiral. In addition, the linear coordination displayed by gold(I) complexes places the chiral ligand far away from the substrate resulting in an inefficient transfer of chiral information....

Alkynylcyclopropanes have found promising applications in both organic synthesis and medicinal chemistry but remain rather underexplored due to the challenges associated with their preparation. We describe a convenient two-step methodology for the alkynylcyclopropanation of alkenes, based on the rhodium(II)-catalyzed decarbenation of 7-alkynyl cycl...

A library of gold(I) chloride complexes with phosphine ligands incorporating pendant (thio)urea and squaramide H‐bond donors was prepared with the aim of promoting chloride abstraction from Au(I) via H‐bonding. In the absence of silver additives, complexes bearing squaramides and trifluoromethylated aromatic ureas displayed good catalytic activity...

The ability of highly energetic metal–carbene intermediates to engage in complex cascade or formal cycloaddition processes is one of the most powerful tools for building intricate molecular architectures in a straightforward manner. Among this type of organometallic intermediates, non-acceptor metal carbenes are particularly challenging to access a...

Chiral gold(I)‐cavitand complexes have been developed for the enantioselective alkoxycyclization of 1,6‐enynes. This enantioselective cyclization has been applied for the first total synthesis of carbazole alkaloid (+)‐mafaicheenamine C and its enantiomer, establishing its configuration as R. The cavity effect was also evaluated in the cycloisomeri...

The Rh(III)-catalyzed ortho-alkynylation of benzaldehydes is enabled by the transient formation of an imine as a directing group. A broad scope of substrates was obtained under mild reaction conditions, granting access to mono- and dialkynylated products. The functionalization of readily available building blocks allowed the development of modular...

Non‐activated olefins react with TIPS‐bromoacetylene under directing group‐free RhIII catalysis to afford 1,4‐enynes in a linear‐selective fashion. The developed protocol performs on mild conditions and a vast array of functional groups are tolerated, including weak aryl‐directing groups and disubstituted olefins, where no over functionalization is...

A new family of chiral gold(I)‐cavitand complexes was designed and applied to the development of the first enantioselective alkoxycyclization of phenyl‐linked 1,6‐enynes, giving high enantioselectivities and excellent yields. This approach was used for the first total synthesis of carbazole alkaloid (+)‐mafaicheenamine C. The cavity effect was stud...

Non‐activated olefines reacts with TIPS‐bromoacetylene under directing group‐free RhIII catalysis to afford 1,4‐enynes in a linear‐selective fashion. The developed protocol performs on mild conditions and a vast array of functional groups are tolerated, including weak aryl‐directing groups and disubstituted olefins, where no over functionalization...

Gold(I) chloride complexes are stable, widespread precatalysts that generally require activation by halide abstraction to display useful catalytic activity. Chloride scavenging is typically performed in situ by using silver salts. This procedure, apart from mandating the use of an additional metal, often negatively impacts the reaction outcome, bec...

The formation of s-indaceno[1,2-b:5,6-b']ditetracene and as-indaceno[2,3-b:6,7-b']ditetracene containing indenofluorene cores from a common precursor has been achieved by a dehydrogenative surface-assisted cyclization on Au(111) and confirmed by bond-resolved non-contact atomic force microscopy. On-surface generated as-indaceno[2,3-b:6,7-b']ditetra...

The formal (4+3) cycloaddition of 1,3‐dienes with Rh(II) and Au(I) non‐acceptor vinyl carbenes, generated from vinylcycloheptatrienes or alkoxyenynes, respectively, leads to 1,4‐cycloheptadienes featuring complex and diverse substitution patterns, including natural dyctiopterene C′ and a hydroxylated derivative of carota‐1,4‐diene. A complete mecha...

The nature of cyclopropyl gold(I) carbene‐type intermediates has been reexamined as part of a mechanistic study on the formation of cis‐ or trans‐fused bicyclo[5.1.0]octanes in a gold(I)‐catalyzed cascade reaction. Benchmark of DFT methods together with QTAIM theory and NBO analysis confirms the formation of distinct intermediates with carbenic or...

Three- and four-membered rings, widespread motifs in nature and medicinal chemistry, have fascinated chemists ever since their discovery. However, due to energetic considerations, small rings are often difficult to assemble. In this regard, homogeneous gold catalysis has emerged as a powerful tool to construct these highly strained carbocycles. Thi...

Metal vinyl carbenes generated by retro‐Buchner reaction or an enyne cycloisomerization cascade react with 1,3‐dienes to afford complex 1,4‐cycloheptadienes in a formal (4+3) cycloaddition process. A combination of experiments and computations provides a full mechanistic picture in which two pathways, a vinylcyclopropanation/Cope rearrangement or a...

On-surface synthesis is becoming an increasingly popular approach to obtain new organic materials. In this context, metallic surfaces are the most commonly used substrates. However, their hybridization with the adsorbates often hinder a proper characterization of the molecule’s intrinsic electronic and magnetic properties. Here we report a route to...

Modifications at the bridgehead position of englerin A were made to explore the effects of variation at this site on the molecule for biological activity, as judged by the NCI 60 screen, in which englerin A is highly potent and selective for renal cancer cells. Replacement of the isopropyl group by other, larger substituents yielded compounds which...

Auration of o‐trimethylsilyl arylphosphines leads to the formation of gold and gold–silver clusters with ortho‐metalated phosphines displaying 3c–2e Au−C−M bonds (M=Au/Ag). Hexagold clusters [Au6L4](X)2 are obtained by reaction of (L−TMS)AuCl with AgX, whereas reaction with AgX and Ag2O leads to gold–silver clusters [Au4Ag2L4](X)2. Oxo‐trigold(I) s...

An Ir‐catalyzed C(sp³)−H alkynylation of aliphatic ketones, aldehydes, and alcohols was achieved by using the corresponding oxime derivatives and a IrIII catalyst. This general reaction is selective towards primary C(sp³)−H bonds and can be used for the late‐stage C−H alkynylation of complex molecules. image

Kilian Muñiz verstarb plötzlich am 16. März 2020 im Alter von nur 49 Jahren. Kilian war einer der führenden Akteure auf dem Gebiet der katalytischen (Di‐)Aminierungen. Er wird als erstklassiger, leidenschaftlicher Chemiker, wunderbarer Kollege und vor allem als Freund in Erinnerung bleiben.

Kilian Muñiz passed away unexpectedly on March 16th, 2020, at the age of only 49. Kilian was a leading figure in the field of catalytic (di‐)amination reactions. He will be remembered as one of the finest, most passionate chemists, a dear colleague, and, most of all, as a close friend. image

The photoredox-assisted gold-catalyzed arylative cyclization of 1,6-enynes with aryldiazonium salts gives rise to cyclization products with the opposite configuration at the alkene than that obtained by gold(I)-catalyzed alkoxycyclization. The reaction occurs under mild conditions and shows high functional group tolerance.

An Ir‐catalyzed C(sp³)−H alkynylation of aliphatic ketones, aldehydes, and alcohols was achieved by using the corresponding oxime derivatives and a IrIII catalyst. This general reaction is selective towards primary C(sp³)−H bonds and can be used for the late‐stage C−H alkynylation of complex molecules. Abstract An Ir‐catalyzed C(sp³)−H alkynylatio...

We report on the effect of sp3 hybridized carbon atoms in acene derivatives adsorbed on metal surfaces, namely decoupling the molecules from the supporting substrates. In particular, we have used a Ag(100) substrate and hydrogenated heptacene molecules, in which the longest conjugated segment determining its frontier molecular orbitals amounts to f...

Dialkyl biarylphosphine ligands, presented in the context of Pd‐catalyzed cross‐coupling reactions, have been extensively applied in gold(I) catalysis giving rise to numerous transformations and reaction pathways otherwise inaccessible under the action of other gold(I) catalysts. This review emphasizes how this privileged ligand class, as well as r...

The rhodium(II)-catalyzed assembly of densely-substituted cis-configured cyclopropyl ethers by decarbenation of cycloheptatrienes is reported. At higher temperature, these non-acceptor cyclopropanes open to give all-E trienes under the same catalytic system, in a one-pot procedure. Experimental and computational studies show that, for the formation...

The gold(I)‐catalyzed reaction of acetylene gas with alkenes leads to (Z,Z)‐1,4‐disubstituted 1,3‐butadienes and biscyclopropanes depending on the donor ligand on gold(I). Acetylene was generated in situ from calcium carbide and water in a user‐friendly procedure. Reaction of acetylene with 1,5‐dienes gives rise stereoselectively to tricyclo[5.1.0....

Manipuliertes Verhalten: Acetylengas verhält sich wie ein Dicarben in der Anwesenheit von Gold(I). Dieses Konzept wurde in der Einschritt‐Totalsynthese des Naturstoffs Waitziacuminon aus Acetylen und Geranylaceton eingesetzt. Abstract The gold(I)‐catalyzed reaction of acetylene gas with alkenes leads to (Z,Z)‐1,4‐disubstituted 1,3‐butadienes and b...

Decarboxylative Csp3-N coupling reactions have been developed through electrochemical oxidation of amino acids. The reaction proceeds via anodic oxidative decarboxylation of carboxylic acids to form stabilized carbocations, which are trapped by azoles or amides to construct C-N bonds. This method avoids the preactivation of carboxylic acids and the...

The gold(I)-catalyzed reaction of bromoalkynes with allylsilanes gives 1,4-enynes in a formal cross-coupling reaction. Mechanistic studies revealed the involvement of gold(I) vinylidenes or vinylidenephenonium gold(I) cations depending on the substituent on the bromoalkyne. In the case of bromo arylalkynes, the vinylidenephenonium gold(I) cations l...

Chiral gold(I) catalysts have been designed based on a modified JohnPhos ligand with a distal C2-2,5-diarylpyrrolidine that creates a tight binding cavity. The C2-chiral element is close to where the C-C bond formation takes place in cyclizations of 1,6-enynes. These chiral mononuclear catalysts have been applied for the enantioselective 5-exo-dig...

The quest for organic materials with improved optoelectronic properties has stimulated the development of new strategies for the preparation of polycyclic aromatic hydrocarbons. Within this context, transition metal catalysis offers unparalleled opportunities for the assembly of complex molecular architectures. The palladium-catalyzed direct C-H ar...

The synthesis of novel fluorinated symmetrical and unsymmetrical imidazolium salts as well as their corresponding coinage metal complexes is described. The silver derivatives were prepared using Ag2O as the metal source and the subsequent (NHC)AgX complexes were successfully employed in the preparation of the corresponding Cu(I) and Au(I) complexes...

The picture shows a group of flamingos taken off the Long lagoon of Villacañas in Toledo (La Mancha), Spain. The picture was taken by one of the authors (Antonio M. Echavarren) in June 2018. The last flamingo (representing gold carbenes) is catching up the front‐runners of transition metal carbene‐catalyzed C(sp3)−H insertion chemistry. More inform...

A novel synthesis of indanes and dihydronaphtalenes based on the intramolecular insertion into C(sp³)−H bonds of gold(I) carbenes generated by retro‐Buchner reaction (decarbenation) has been developed. Deuterium‐labeling and kinetic isotope effect experiments, DFT calculations, and generation of the proposed carbene intermediate from a well‐charact...

this Data Descriptor announces the submission to public repositories of the monoterpene indole alkaloid database (MIADB), a cumulative collection of 172 tandem mass spectrometry (MS/MS) spectra from multiple research projects conducted in eight natural product chemistry laboratories since the 1960s. All data have been annotated and organized to pro...

A gold(I)-catalyzed cyclopropane-alkene metathesis has been demonstrated with two new families of cyclopropane derivatives of naphthalene and phenanthrene (benzo-fused norcaradienes). In this process, metal carbene units are transferred from a...

Mesityl gold(I) carbenes lacking heteroatom stabilization or shielding ancillary ligands have been generated and spectroscopically characterized from chloro(mesityl)methylgold(I) carbenoids bearing JohnPhos‐type ligands by chloride abstraction with GaCl3. The aryl carbenes react with PPh3 and alkenes to give stable phosphonium ylides and cyclopropa...

Rhodium carbenes are key intermediates in a range of cycloadditions and insertion reactions. Herein, we report the first generation of donor RhII carbenes by decarbenation of 7‐substituted 1,3,5‐cycloheptatrienes. This discovery unlocks an improved retro‐Buchner‐cyclopropanation sequence, a Si−H insertion reaction for a broad‐scope synthesis of all...

Mesityl gold(I) carbenes lacking heteroatom stabilization or shielding ancillary ligands have been generated from chloro(mesityl)methylgold(I) carbenoids bearing JohnPhos‐type ligands by chloride abstraction with GaCl3. These new family of aryl gold(I) carbenes have been characterized spectroscopically at low temperatures. The aryl carbenes react w...

The goal of this short review is to provide an overview of the different synthetic methodologies applied along the years for the synthesis of bullvalenes, prototypical fluxional molecules that were key in the understanding of valence tautomerism phenomena. Some interesting applications of these unique shapeshifting compounds are also presented. 1 I...

Rhodium carbenes are key intermediates in a range of cycloadditions and insertion reactions. Whereas Rh(II) carbenes bearing acceptor substituents are easily accessed from stabilized diazo compounds, general and safe methods for accessing donor Rh(II) carbenes are scarce. Herein, we report the first generation of donor Rh(II) carbenes by decarbenat...

The gold(I)‐catalyzed retro‐Buchner (decarbenation, retrocyclopropanation) reaction of 7‐substituted cycloheptatrienes has emerged as a safe and powerful alternative for the generation of gold(I) carbenes. These carbenes can cyclopropanate alkenes, take part in intramolecular reactions, or engage in higher cycloadditions with different partners, gi...

The analysis of reactant, intermediates and end product heptacene reveals the dependence of band gap, stability and molecular charge state on the extent of the longest conjugated acene segment. For intermediate 2, featuring a pentacene segment, the appearance and behavior of charging peaks and a zero-bias anomaly are all in good agreement with a sc...

The first total synthesis of repraesentin F has been accomplished by a highly diastereoselective gold(I)-catalyzed cyclization cascade as the key step. This cycloisomerization/Prins-type tandem transformation enabled direct access to the atypical tricyclic carbon skeleton of the natural product with the required syn/anti/syn ring fusion. This synth...

Achieving the Ag(001)-supported synthesis of heptacene from two related reactants reveals the effect of the presence of Br atoms on the reaction process. The properties of reactants, intermediates and end-products are further characterized by scanning tunneling microscopy and spectroscopy.

The reaction of oxime-tethered 1,6-enynes with a cationic gold(I) catalyst demonstrates a great potential for the synthesis of a range of heterocycles in a diastereospecific fashion. The control of the configuration of the oxime and the alkene of the enyne moiety is the key to obtain selectively dihydro-1,2-oxazines, isoxazoles or dihydropyrrole-N-...

Achieving the Ag(001)-supported synthesis of heptacene from two related reactants reveals the effect of the presence of Br atoms on the reaction process. The properties of reactant, intermediates and end-product are further characterized by scanning tunneling microscopy and spectroscopy.

Gold(I) complexes are the catalysts of choice for the selective activation of alkynes in the presence of other unsaturated functional groups. In this Account, we present the development of gold(I)-catalyzed intermolecular reactions of terminal alkynes with functionalized alkenes. In particular, we focus on the synthesis of cyclobutenes by asymmetri...

Arsine and carbene gold(I) complexes with architectures closely related to those of 2-(di-tert-butylphosphino)biphenyl gold(I) complexes have been prepared and structurally characterized. As predicted, 2-(di-tert-butylarsine)biphenyl gold(I) complexes are more electrophilic catalysts in comparison to their phosphine analogues, whereas those based o...

Through the design of a second generation of more reactive 7-substituted 1,3,5-cycloheptatrienes, a room-temperature gold(I)-catalyzed retro-Buchner–cyclopropanation sequence and the first zinc(II)-catalyzed version of this process, which uses inexpensive ZnBr2 as catalyst, have been developed. This led to a broad-scope cyclopropanation of both act...

The Front Cover shows a cube‐shaped monument in Madrid to the Spanish Constitution. The stairs in each face invite people to ascend to the core of the cube, with the impetus to improve the society through democracy. The square faces of the cube with stairs remind us of the unsaturated four‐membered rings of cyclobutenes, which are important buildin...

A unified approach to the synthesis of the series of higher acenes up to previously unreported undecacene has been developed through the on‐surface dehydrogenation of partially saturated precursors. These molecules could be converted into the parent acenes by atomic manipulation with the tip of a scanning tunneling and atomic force microscope (STM/...

A unified approach to the synthesis of the series of higher acenes up to previously unreported undecacene has been developed through the on‐surface dehydrogenation of partially saturated precursors. These molecules could be converted into the parent acenes by atomic manipulation with the tip of a scanning tunneling and atomic force microscope (STM/...

Gold(I)‐catalyzed cycloisomerizations of 1,n‐enynes proceed through electrophilic intermediates that can be trapped intra‐ or intermolecularly by a variety of hetero‐ and carbon nucleophiles to form complex skeletons in a single step. This review covers the efforts of our group towards the development of new reactions that have been successfully ap...