Israel Fernández

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Verified

Israel verified their affiliation via an institutional email.

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• Professor
• Professor at Complutense University of Madrid

The chemical reduction of a bilayer spironanographene, spiro‐NG (C137H120), with Na and K metals in the presence of [2.2.2]cryptand to yield [Na⁺(2.2.2‐cryptand)](C137H121⁻) (1) and [K⁺(2.2.2‐cryptand)](C137H121⁻) (2), respectively, is reported. X‐ray crystallography reveals the formation of a new “naked” anion (spiro‐NGH⁻), in which spirocyclic ri...

The chemical reduction of a bilayer spironanographene, spiro‐NG (C137H120), with Na and K metals in the presence of [2.2.2]cryptand to yield [Na+(2.2.2‐cryptand)](C137H121–) (1) and [K+(2.2.2‐cryptand)](C137H121–) (2), respectively, is reported. X‐ray crystallography reveals the formation of a new “naked” anion (spiro‐NGH–), in which spirocyclic ri...

The unexpected reactivity and stability limits of phosphorus ylide‐based aluminum– and gallium–carbon ambiphiles are described. While the previously published t‐butyl‐substituted compound (2‐{AltBu2}‐C6H4)Ph2PCMe2 (1tBu) reacts reversibly with NH3 at room temperature (RT) with cleavage of a NH bond, the reaction with MeNH2 is much less favorable an...

Herein, we present a comprehensive computational study of the reaction mechanism and regioselectivity patterns of the phosphine-catalyzed Heine reaction involving N-benzoylaziridines. Density functional theory (DFT) calculations reveal that the regioselectivity of the process takes place under kinetic control, favoring the formation of the correspo...

The reaction of CO2 with seven molecules featuring a 1,4‐diborinine central ring is studied by means of density functional theory calculations. The selected systems present five‐ and six‐membered aza rings surrounding the 1,4‐diborinine with neutral, anion, and dianion charges. In all cases, the reaction is exothermic and exergonic. The computed re...

We explored herein the coordination properties of bis(phosphine)NHC→BH3 ligand toward cationic and neutral Cu centres. The synthesis of three dinuclear Cu complexes featuring σ-BH interactions is reported. Noticeably, in each...

The impact of the nature of the Group 15 element on both the bonding situation and the reactivity of gold­(I)-C ≡ E (E = N to Bi) complexes has been studied quantum chemically within the density theory functional framework. For this purpose, the 1,3-dipolar cycloaddition reaction involving tBuN3 as dipole has been selected and its main features, in...

1,5-Disubstituted bicyclo[2.1.1]hexanes are bridged scaffolds with well-defined exit vectors that are becoming increasingly popular building blocks in medicinal chemistry because they are saturated bioisosteres of ortho-substituted phenyl rings. Here we have developed a Lewis-acid-catalysed [2 + 2] photocycloaddition to obtain these motifs as enant...

The reaction between NHC-supported (NHC = N-heterocyclic carbene) gold(i) trimethylsilylacetylide complexes with NHC gold(i) hydroxide species renders different symmetrical homobimetallic Au complexes. These compounds readily undergo migratory insertion of DMAD (dimethyl acetylenedicarboxylate) at 25 °C to give the corresponding bimetallic enyne pr...

Open-shell systems based on first-row transition metals and their involvement in various catalytic processes are well explored. By comparison, mononuclear open-shell complexes of precious transition metals remain underdeveloped. This is particularly true for IrII complexes, as there is very limited information available regarding their application...

Herein, we describe how minor structural modifications to our bifunctional organocatalysts based on sugar amino acids (SAAs) can alter the network of non‐covalent interactions (NCIs) within the catalyst, leading to significant changes in their catalytic activity. This is attributed to the intra‐catalyst NCIs, which induce conformational changes tha...

The introduction of 4,5‐dihydroazuleno[2,1,8‐ija]azulene as a central core between two 1,4‐dithiafulvene (DTF) units provides a novel class of extended tetrathiafulvalene (TTF) electron donors. Herein we present the synthesis of such compounds with the azulenoazulene further expanded by annulation to benzene, naphthalene, or thiophene rings. Moreov...

This work provides an in‐depth analysis of the factors governing the different reaction pathways in the acid‐catalyzed cyclization of gem‐vinylsilyl alcohols with aldehydes. The study evaluates the impact of both the ligands attached to silicon and the choice of the Lewis acid on the reaction outcome. Additionally, computational studies offer valua...

Stereoselective control of molecular nanographene helicity has been achieved by a point-to-helical chirality transfer during the Scholl graphitization reaction to obtain compound 4. Density functional theory calculations indicate that the complete diastereoselective process takes place mainly under kinetic control. Circular dichroism and circularly...

The introduction of 4,5‐dihydroazuleno[2,1,8‐ija]azulene as a central core between two 1,4‐dithiafulvene (DTF) units provides a novel class of extended tetrathiafulvalene (TTF) electron donors. Herein we present the synthesis of such compounds with the azulenoazulene further expanded by annulation to benzene, naphthalene, or thiophene rings. Moreov...

An active catalytic system for the cross-dehydrogenative coupling (CDC) of a wide range of secondary amines with silanes is reported. The iridium(III) derivatives [Ir(H)(X)(κ²-NSiDMQ)(L)] (NSiDMQ = {4,8-dimethylquinoline-2-yloxy}dimethylsilyl; L = coe, X = Cl, 2; L = coe, X = OTf, 3; L = PCy3, X = Cl, 4; L = PCy3, X = OTf, 5), which are stabilized...

A facile photochemical, one‐pot synthesis of highly functionalized 1‐aminotetralins derivatives (>70 examples) from readily accessible o‐alkyl and o‐formyl aryl silylimines with olefins is described. A diradical‐mediated hydrogen atom transfer (DHAT) of primary, secondary, and tertiary C(sp³)−H bonds of o‐alkyl arylsilylimines and C(sp²)−H bonds of...

The poorly understood factors controlling the reactivity and selectivity (both stereo‐ and enantioselectivity) of catalyzed Diels‐Alder reactions involving cyclobutenones as dienophiles have been analyzed in detail by means of Density Functional Theory calculations. To this end, the reactions with cyclopentadiene and furan as dienes and 3‐(methoxyc...

A facile photochemical, one‐pot synthesis of highly functionalized 1‐aminotetralins derivatives (> 70 examples) from readily accessible o‐alkyl and o‐formyl aryl silylimines with olefins is described. A diradical‐mediated hydrogen atom transfer (DHAT) of primary, secondary, and tertiary C(sp3)−H bonds of o‐alkyl arylsilylimines and C(sp2)−H bonds o...

A computational approach to directly estimate the relative acidity of a given Lewis acid is presented. This approach is based on the strength of the π‐conjugation in trans‐crotonaldehyde‐Lewis acid complexes, the species used in the well‐known Childs’ Lewis acidity scale. It is found that the π‐conjugative strength values given by the Energy Decomp...

Organic dyes are interesting building blocks for the preparation of organic semiconductors as they possess synthetic handles that can be used to functionalize them and, consequently, change their electronic properties. However, reactions to extend their π‐conjugated framework through ring annulation have only been scarcely tested. Herein, we report...

The synthesis of diradical organic compounds has garnered significant attention due to their thermally accessible spin inversion and optoelectronic properties. Yet, preparing such stable structures with high open‐shell behavior remains challenging. Herein, we report the synthesis and properties of four π‐extended, fused fluorene derivatives with hi...

The synthesis of housane derivatives from cyclopropenes is described. Under rhodium(II) catalysis, cyclopropenylvinyl carbinols can regioselectively generate a carbene intermediate which undergoes an intramolecular cyclopropanation to form a housane, a skeleton with similar ring strain as the cyclopropene precursor. The procedure shows a remarkable...

The catalytic performance of a series of mono‐ and bimetallic Ir(I) and Rh(I) complexes bearing the (COC) bis‐triazolylidene ligand, coordinated in a bridging or chelating fashion, was evaluated in the cyclization of 4‐pentynoic acid. The chelated mononuclear cationic complex [Ir(cod)(COC)]PF6 (cod=1,5‐cyclooctadiene; COC=biscarbene ether) displaye...

The synthesis of diradical organic compounds has garnered significant attention due to their thermally accessible spin inversion and optoelectronic properties. Yet, preparing such stable structures with high open‐shell behavior remains challenging. Herein, we report the synthesis and properties of four π‐extended, fused fluorene derivatives with hi...

New and simple ligand design strategies for the preparation of versatile metal-based catalysts capable of operating under greener and eco-friendly conditions in several industrially attractive processes are a priority demand...

A bare lead atom is a σ-donor ligand capable of linearly bonding and stabilizing two units of a classical polyhydride complex, with a high-valent metal center. As a proof of concept, we have prepared and characterized the μ2-tetrylide complex (PⁱPr3)2H4Os=Pb=OsH4(PⁱPr3)2 in the reaction of OsH6(PⁱPr3)2 with Pb{N(SiMe3)2}2. Although the Pb–Os bonds...

Detailed quantum‐chemical calculations have been carried out to understand both the origin of the catalysis in the urea‐catalyzed nucleophilic ring‐opening of nitrocyclopropanes and the acceleration induced by the presence of an internal Lewis acid in the catalyst. To this end, the mode of activation of these ureas is quantitatively analyzed in det...

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...

The synthesis of housanes derivatives from cyclopropenes is described. Under rhodium(II) catalysis, cyclopropenylvinyl carbinols can regioselectively generate a carbene intermediate which undergo an intramolecular cyclopropanation to form a housane, a skeleton with similar ring strain as the cyclopropene precursor. The procedure shows a remarkable...

The discovery of unique mechanisms in 3d metal catalysis is of paramount importance in utilising these Earth-abundant metals in place of scarce precious metals. Inspired by the Horiuti-Polanyi mechanism at play in heterogenous hydrogenation catalysts, we describe a bimetallic molecular catalyst which can selectively semi-hydrogenate alkynes via a l...

Quantum chemical calculations were carried out to quantitatively understand the origin of the Felkin–Anh(–Eisenstein) model, widely used to rationalize the π-facial stereoselectivity in the nucleophilic addition reaction to carbonyl groups directly attached to a stereogenic center. To this end, the possible approaches of cyanide to both (S)-2-pheny...

The factors controlling the activation of σ‐bonds promoted by hidden Frustrated Lewis Pairs have been computationally explored using quantum chemical tools. To this end, the influence of both the nature of the group 13 element acting as Lewis acid as well as the cooperative action of the Lewis antagonists on the bond activation was quantitatively a...

Conjugated dienes (1,3-dienes) are versatile and valuable chemical feedstocks that can be used as two-carbon or four-carbon synthons with vast applications across the chemical industry. However, the main challenge for their productive incorporation in synthetic routes is their chemo-, regio-, and stereoselective functionalization. Herein, we introd...

The chemistry of mononuclear open-shell complexes of precious transition metals is largely underdeveloped, which contrasts with that of first-row transition metals and their catalytic applications. This is particularly true for IrII complexes and its almost inexistent participation in catalysis. Here we report the synthesis and characterization of...

The synthesis, structure, and catalytic activity of a Ti(II)/Ti(III) inverted sandwich compound are presented in this study. Synthesis of the arene-bridged dititanium compound begins with the preparation of the titanium(IV) precursor [TiCl2(MesPDA)(thf)2] (MesPDA = N,N′-bis(2,4,6-trimethylphenyl)-o-phenylenediamide) (2). The reduction of 2 with sod...

Catalysts generated in situ by the combination of pyridine–hydrazone N,N-ligands and Pd(TFA)2 have been applied to the addition of arylboronic acids to formylphosphonate-derived hydrazones, yielding α-aryl α-hydrazino phosphonates in excellent enantioselectivities (96 → 99% ee). Subsequent removal of the benzyloxycarbonyl (Cbz) N-protecting group a...

Directional bonding strategies guide the design of complex molecular architectures, yet challenges arise due to emergent behavior. Rigid structures face geometric constraints and sensitivity to mismatches, hindering the efficient assembly of molecular organic cages (MOCs). Harnessing intramolecular non‐covalent interactions offers a promising solut...

We report on the synthesis and characterization of a series of (mostly) air‐stable diorganyl bis(pyridylimino) isoindolide (BPI) aluminum complexes and their chemistry upon visible‐light excitation. The redox non‐innocent BPI pincer ligand allows for efficient charge transfer homolytic processes of the title compounds. This makes them a universal p...

We report on the synthesis and characterization of a series of (mostly) air‐stable diorganyl bis(pyridylimino) isoindolide (BPI) aluminum complexes and their chemistry upon visible‐light excitation. The redox non‐innocent BPI pincer ligand allows for efficient charge transfer homolytic processes of the title compounds. This makes them a universal p...

A straightforward and selective conversion of nitriles into highly substituted tetrahydropyridines, aminoketones or enamines by using allylmagnesium bromide as an addition partner (under neat conditions) and subsequent treatment with different aqueous-based hydrolysis protocols is reported. Refuting the conventional wisdom of the incompatibility of...

The factors governing the acceleration of the oxidative addition of methyl iodide to pincer rhodium(I)‐complexes induced by coronene have been computationally explored in detail using quantum chemical methods. Both the parent reaction and the coronene‐mediated process proceed via a stepwise SN2‐type mechanism. It is found that the acceleration of t...

The origin of the electrophilicity of a series of cyclohexanones and benzaldehydes is investigated using the activation strain model and quantitative Kohn–Sham molecular orbital (MO) theory. We find that this electrophilicity is mainly determined by the electrostatic attractions between the carbonyl compound and the nucleophile (cyanide) along the...

The factors governing 1,3‐dipolar cycloaddition reactions involving C≡P‐containing compounds are computationally explored in detail using quantum chemical tools. To this end, the parent process involving tBuN3 and tBuCP is analyzed and compared to the analogous reaction involving organometallic cyaphide complexes (metal=Au, Pt, Ge, Mg), in order to...

Herein, we present that the radicals [Ph3PC(Me)EMes2]• (2Si and 2Ge) can be generated from the α silylated and α-germylated phosphorus ylides Ph3PC(Me)E(Cl)Mes2 (1Si and 1Ge) through one-electron reduction with Jones’...

Quantum‐chemical (DFT) calculations on hitherto unknown base(carbene)‐stabilized gallium monoiodides (LB→GaI) suggest that these systems feature one lone pair of electrons and a formally vacant p‐orbital – both centered at the central gallium atom – and exhibit metallomimetic behavior. The calculated reaction free energies as well as bond dissociat...

Herein, we report the use of isonitriles as alkyl radical precursors in light‐mediated hydro‐ and deuterodeamination reactions. The reaction is scalable, shows broad functional group compatibility and potential to be used in late‐stage functionalization. Importantly, the method is general for Cα‐primary, Cα‐secondary and Cα‐tertiary alkyl isonitril...

Non-alternant non-benzenoid hydrocarbons exhibit unique properties compared to their well-studied benzenoid counterparts. However, the synthesis of these structures with extended π-conjugation or their integration into established benzenoid frameworks presents ongoing...

Herein, we report the use of isonitriles as alkyl radical precursors in light‐mediated hydro‐ and deuterodeamination reactions. The reaction is scalable, shows broad functional group compatibility and potential to be used in late‐stage functionalization. Importantly, the method is general for Cα‐primary, Cα‐secondary and Cα‐tertiary alkyl isonitril...

We report on so‐called “hidden FLPs” (FLP: frustrated Lewis pair) consisting of a phosphorus ylide featuring a group 13 fragment in the ortho position of a phenyl ring scaffold to form five‐membered ring structures. Although the formation of the Lewis acid/base adducts was observed in the solid state, most of the title compounds readily react with...

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...

The mechanism and selectivity patterns of the DABCO-catalyzed Cloke–Wilson rearrangement were computationally studied in detail using density functional theory calculations. Our computations suggest that the process occurs stepwise involving the initial ring opening of the cyclopropane promoted by a DABCO molecule followed by a ring-closure reactio...

Understanding the geometrical preferences in chemical reactions is crucial for advancing the field of organic chemistry and improving synthetic strategies. One such preference, the Bürgi-Dunitz angle, is central to nucleophilic addition reactions involving carbonyl groups. This study successfully employs a novel two-dimensional Distortion-Interacti...

1,5-Disubstituted bicyclo[2.1.1]hexanes are bridged scaffolds with well-defined exit vectors that are becoming increasingly popular building blocks in medicinal chemistry since they are saturated bioisosteres of orthosubstituted phenyl rings. Here we have developed the first enantioselective catalytic strategy based on a Lewis acid-catalyzed [2+2]...

Despite recent achievements in the field of frustrated Lewis pairs (FLPs) for small molecule activations, the reversible activation and catalytic transformations of N–H-activated ammonia remain a challenge. Here we report on a rare combination of an aluminium Lewis acid and a carbon Lewis base. A so-called hidden FLP consisting of a phosphorus ylid...

The reactivity and endo/exo selectivity of the Diels-Alder cycloaddition reactions involving furan and substituted furans as dienes have been computationally explored. In comparison to cyclopentadiene, it is found that furan is comparatively less reactive and also less endo-selective in the reaction with maleic anhydride as the dienophile. Despite...

In this themed collection, we embark on a captivating journey into the realm of aromaticity, a fundamental concept that has attracted chemists for nearly two centuries. This virtual collection offers a comprehensive overview of the recent advances in the field, encompassing thirty manuscripts published in Chemical Science from 2021 to the present....

The successful architecture of active catalytic species with enhanced efficiencies is critical for the optimal exploitation of sustainable resources in industrially demanded processes. In this work, we describe the preparation of novel helical heterobimetallic Al/Mg-based complexes of the type [AlMe2(pbpamd-)MgR{κ1-O-(OC4H8O)}] [R = Et (1a), tBu (2...

Understanding the geometrical preferences in chemical reactions is crucial for advancing the field of organic chemistry and improving synthetic strategies. One such preference, the Bürgi-Dunitz angle, is central to nucleophilic addition reactions involving carbonyl groups. This study successfully employs a novel two-dimensional Distortion-Interacti...

Analyzing activation strain, energy decomposition, and reaction force models is crucial for studying chemical reactivity and gaining quantitative insights into the factors that control energy barriers. However, manually preparing and processing the necessary data can be challenging and prone to errors. To address this issue, we introduce SurfinPES,...

The physical factors governing the catalysis in Lewis acid-promoted carbonyl-ene reactions have been explored in detail quantum chemically. It is found that the binding of a Lewis acid to the carbonyl group directly involved in the transformation greatly accelerates the reaction by decreasing the corresponding activation barrier up to 25 kcal/mol....

Non‐innocent ligands (NILs) like bis(pyridylimino)isoindolide (BPI) play crucial roles in coordination chemistry, biosciences, catalysis and material sciences. Investigating the isolated redox states of NILs is inevitable for understanding their redox‐activity and fine‐tuning the properties of corresponding metal complexes. The limited number of fu...

The Bürgi‐Dunitz (BD) angle plays a pivotal role in organic chemistry to rationalize the nucleophilic addition to carbonyl groups. Yet, the origin of the obtuse trajectory of the nucleophile remains incompletely understood. Herein, we quantify the importance of the underlying physical factors quantum chemically. The obtuse BD angle appears to origi...

Comprehensive computational investigations were carried out to understand the electronic and ligand properties of skeletally substituted β-diketiminate stabilized Al(I) and Ga(I) carbenoids as well as to probe their potential in small molecule activation. All of the proposed group 13 carbenoids possess a stable singlet ground state, and the majorit...

We report herein the synthesis of a bisphosphine-[NHC-BH3] compound and its coordination toward gold. The ligand is shown to support a bimetallic structure bisphosphine-[NHC-BH3](AuCl)2. The abstraction of one chloride from the gold metal center triggers the activation of a BH3 fragment, leading to the reductive elimination of H2 and the formation...

The poorly understood factors governing the small molecule activation reactions mediated by diazaborinines have been computationally explored in detail using quantum chemical tools. To this end, the activation of E−H σ‐bonds (E = H, C, Si, N, P, O, S) has been investigated. These reactions, which proceed in a concerted manner, are exergonic and, in...

Aromaticity is one of the most deeply rooted concepts in chemistry. But why, if two-thirds of existing compounds can be classified as aromatic, is there no consensus on what aromaticity...

While the synthesis of nanographenes has advanced greatly in the past few years, development of their atomically precise functionalization strategies remains rare. The ability to modify the carbon scaffold translates to controlling, adjusting, and adapting molecular properties. Towards this end, here, we show that mechanochemistry is capable of tra...

The reaction of the oxygen‐bridged frustrated Lewis pairs (FLPs) tBu2P−O−Si(C2F5)3 (1) and tBu2P−O−AlBis2 (2) with azobenzene, promoted by UV irradiation, led to a selective complexation of the cis‐isomer. The addition product of 2 is stable, while the adduct of 1 isomerizes in solution in an ortho‐benzidine‐like [3,3]‐rearrangement by cleavage of...

Non‐alternant non‐benzenoid hydrocarbons exhibit very different optical and electronic properties than their well‐studied benzenoid analogues. However, preparing such structures with extended conjugation length, remains challenging. Herein, we report the synthesis and properties of azuleno[2,1,8‐ija]azulene derivatives using a two‐step sequence inv...

The reaction of the oxygen‐bridged frustrated Lewis pairs (FLPs) tBu2P–O–Si(C2F5)3 (1) and tBu2P–O–AlBis2 (2) with azoben­zene, promoted by UV irradiation, led to a selective complexation of the cis‐isomer. The addition product of 2 is stable, while the adduct of 1 isomerizes in solution in an ortho‐benzidine‐like [3,3]‐rearrange­ment by cleavage o...

Non‐alternant non‐benzenoid hydrocarbons exhibit very different optical and electronic properties than those of their well‐studied benzenoid analogs. Yet, preparing such structures with extended conjugation length, remains challenging. Herein, we report the synthesis and properties of azuleno[2,1,8‐ija]azulenes derivatives using a two‐step sequence...

The poorly understood factors controlling the enhanced reactivity of strained intramolecular frustrated Lewis pairs (FLPs) having a rigid biphenylene tether have been quantitatively explored in detail by means of computational methods. With the help of the activation strain model of reactivity and the energy decomposition analysis methods, the chal...

Scholl oxidation has become an essential reaction in the bottom‐up synthesis of molecular nanographenes. Herein, we describe a Scholl reaction controlled by the electronic effects on the starting substrate (1 a, b). Anthracene‐based polyphenylenes lead to spironanographenes under Scholl conditions. In contrast, an electron‐deficient anthracene subs...

Different electronic effects on the starting anthracene‐containing polyphenylene substrate (bottom) afford two different nanographenes under Scholl reaction conditions, namely, spironanographenes (R=H) on the left, and a helically arranged molecular nanographene having two orthogonal aromatic moieties linked by an octafluoroanthracene core (R=F) on...