An efficient CuI-catalyzed Suzuki–Miyaura reaction was developed for the coupling of aryl- and heteroarylboronate esters with aryl heteroaryl iodides at low catalyst loadings (2 mol %). The proceeds under ligand-free conditions aryl–heteroaryl heteroaryl–heteroaryl couplings. We also conducted first detailed mechanistic studies by synthesizing [(PN-2)CuI]2, [(PN-2)CuF]2, (PN-2)CuPh (PN-2 = o-(di-tert-butylphosphino)-N,N-dimethylaniline) demonstrated that [(PN-2)CuF]2 is species undergoes...

Abstract The catalytic reactivity of the high‐spin Mn II pyridinophane complexes [(Py 2 NR )Mn(H O) ] 2+ (R=H, Me, t Bu) toward O formation is reported. With small macrocycle N‐substituents Me), catalytically disproportionate H in aqueous solution; with a bulky substituent (R= Bu), this reaction shut down, but complex becomes active for electrocatalytic oxidation. Control experiments are support homogeneous molecular catalyst and preliminary mechanistic studies suggest that mononuclear. This...

The alkaline-earth elements (Be, Mg, Ca, Sr, and Ba) strongly favor the formation of diamagnetic compounds in +2 oxidation state. Herein we report a paramagnetic beryllium radical cation, [(CAAC)2Be]+• (2) [CAAC = cyclic (alkyl)(amino)carbene], prepared by zero-valent complex with 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO). Compound 2 was characterized EPR spectroscopy, elemental analysis, X-ray crystallography, DFT calculations. Notably, isolation represents first s-block charged...

In the quest for active and selective catalysts featuring nonprecious metals, bimetallic cooperativity poses a unique opportunity to promote catalytic reactions influence selectivity. While examples of stoichiometric H2 activation across metal–metal bonds have been reported, there limited advances toward incorporation well-defined cooperative process into cycle hydrogenation unsaturated hydrocarbons. Herein, we demonstrate that facile by two metals is facilitated in coordinatively Zr/Co...

The long-sought carbene-bismuthinidene, (CAAC)Bi(Ph), has been synthesized. Notably, this represents both the first example of a carbene-stabilized subvalent bismuth complex and extension carbene-pnictinidene concept to non-toxic metallic element (Bi). bonding investigated by single-crystal X-ray diffraction studies DFT calculations. This report also highlights hitherto unknown reducing ligand transfer capability beryllium(0) complex.

Abstract N‐Heterocyclic carbene (NHC)‐ and cyclic (alkyl)(amino)carbene (CAAC)‐stabilized borafluorene radicals have been isolated characterized by elemental analysis, single‐crystal X‐ray diffraction, UV/Vis absorption, voltammetry (CV), electron paramagnetic resonance (EPR) spectroscopy, theoretical studies. Both the CAAC–borafluorene radical ( 2 ) NHC–borafluorene 4 a considerable amount of spin density localized on boron atoms (0.322 for 0.369 ). In compound , unpaired is also partly...

Borenium ions, originally synthesized as fundamentally important laboratory curiosities, have attracted significant attention due to their applications in catalysis and frustrated Lewis pair chemistry. However, investigations of the materials properties these types compounds are exceptionally rare. Herein, we report synthesis, molecular structures, optical a new class air-stable borenium stabilized by strongly donating carbodicarbene (CDC) ligand (2, 3, 6). Notably, CDC-borafluorenium ions...

Neutral 1-boraphenalene displays the isoelectronic structure of phenalenyl carbocation and is expected to behave as an attractive organoboron multi-redox system. However, isolation new redox states have remained elusive even though preparation neutral boron(III)-containing phenalene compounds been extensively studied. Herein, we adopted N-heterocyclic carbene ligand stabilization approach achieve first stable ambipolar 1-boraphenalenyl radical 1•. The cation 1+ anion 1– also...

Phosphonium ionic liquids (PhosILs), most notably tetradecyl(trihexyl)phosphonium decanoate (PhosIL-C(9)H(1)9COO), are solvents for bases such as Grignard reagents, isocyanides, Wittig reagents (phosphoranes), and N-heterocyclic carbenes (NHCs). The stability of the organometallic species in PhosIL solution is anion dependent. Small bases, hydroxide, react with phosphonium ions promote C-H exchange suggested by deuterium-labeling studies. A method to dry purify described this step important...

The three-fold symmetric, four-coordinate iron(II) phosphoraminimato complexes PhB(MesIm)3Fe–N═PRR′R″ (PRR′R″ = PMePh2, PMe2Ph, PMe3, and PnPr3) undergo a thermally induced S 0 to 2 spin-crossover in fluid solution. Smaller ligands stabilize the low-spin state, an excellent correlation is observed between characteristic temperature of (T1/2) Tolman cone angle (θ). Complexes with para-substituted triaryl (p-XC6H4)3P═N– (X H, Me OMe) also These isosteric reveal that state stabilized by more...

Cinchona alkaloid-derived chiral catalysts represent one of the most widely applied classes organocatalysts, which have been successfully utilized in promotion a wide variety asymmetric reactions. alkaloids exist nature as pseudoenantiomers, allow cinchona alkaloid-catalyzed reactions to provide high enantioselectivities and yields toward both enantiomers interest many On other hand, subtle structural difference between pseudoenantiomeric could also lead uneven efficiency that severely...

Earth-abundant transition-metal catalysts capable of reducing CO2 to useful products have been gaining attention meet increasing energy demands and address concerns rising emissions. Group 6 molecular compounds remain underexplored in this context relative other transition metals. Here, we present a chromium complex with 2,2′-bipyridine-based ligand selectively transforming into CO phenol as sacrificial proton donor at turnover frequencies 5.7 ± 0.1 s–1 high Faradaic efficiency (96 8%) low...

We report a trinuclear copper(II) complex, [(DAM)Cu3(μ3-O)][Cl]4 (1, DAM = dodecaaza macrotetracycle), as homogeneous electrocatalyst for water oxidation to dioxygen in phosphate-buffered solutions at pH 7.0, 8.1, and 11.5. Electrocatalytic 7 occurs an overpotential of 550 mV with turnover frequency ∼19 s–1 1.5 V vs NHE. Controlled potential electrolysis (CPE) experiments 11.5 over 3 h 1.2 8.1 40 min 1.37 NHE confirm the evolution Faradaic efficiencies 81% 45%, respectively. Rinse tests...

The synthesis and reactivity study of the first isolable boraphosphaketene, cyclic(alkyl)(amino) carbene (CAAC)-borafluorene-P=C=O (2), is described. Photolysis compound 2 results in formation CAAC-stabilized BP-doped phenanthryne (3) through tandem decarbonylation, monoatomic phosphide insertion, ring-expansion. Notably, while BN-doped was previously discussed as a reactive intermediate which could not be isolated, heavier analogue exhibits remarkable solution solid-state stability. with...

We report a combined experimental and theoretical study on the first examples of carbodicarbene (CDC)-stabilized bismuth complexes, which feature low-coordinate cationic centers with C=Bi multiple-bond character. Monocations [(CDC)Bi(Ph)Cl][SbF6 ] (8) [(CDC)BiBr2 (THF)2 ][SbF6 (11), dications [(CDC)Bi(Ph)][SbF6 ]2 (9) [(CDC)BiBr(THF)3 ][NTf2 (12), trication [(CDC)2 Bi][NTf2 ]3 (13) have been synthesized via sequential halide abstractions from (CDC)Bi(Ph)Cl2 (7) (CDC)BiBr3 (10). Notably,...

Generally, cobalt–N2O2 complexes show selectivity for hydrogen peroxide during electrochemical dioxygen (O2) reduction. We recently reported a Co(III)–N2O2 complex with 2,2′-bipyridine-based ligand backbone which showed alternative selectivity: H2O was observed as the primary reduction product from O2 (71 ± 5%) decamethylferrocene chemical reductant and acetic acid proton donor in methanol solution. hypothesized that key difference this case arises part increased favorability of protonation...

We report a comprehensive assessment of Lewis acidity for series carbone-stibenium and -bismuthenium ions using the Gutmann-Beckett (GB) method. These new antimony bismuth cations have been synthesized by halide abstractions from (CDC)PnBr3 [(pyCDC)PnBr2][Br] (CDC = carbodicarbene; Pn Sb or Bi; py pyridyl). The reaction (CDC)SbBr3 (1) with one two equivalents AgNTf2 (NTf2 bis(trifluoromethanesulfonyl)imide) AgSbF6 gives stibaalkene mono- dications form [(CDC)SbBr3-n][A]n (2-4; n 1,2; A NTf2...

The syntheses, molecular structures, reactivities, and computational assessment of dipotassium diboratapentacene isomers are described (1 2). These compounds represent the first examples aromatized diboraacenes where boron atoms spatially separated in different rings acene framework. Both 1 2 react with carbon dioxide (CO2) via diastereoselective carboxylation pentacene backbone that likely proceeds by a frustrated Lewis pair-like mechanism. placement reactivity studies provide platform for...

A family of 6-X-2-hydroxyprydine/pyridone (6-X-2-HOpy/pyridone) Cu(II) compounds, [Cu(6-X-2-HOpy)2Cl2] (1 X = F; 2 Cl) and [(6-X-2-pyridone)CuCl(μ-Cl)]2 (3 Cl; 4 Br), has been prepared. Solution-based infrared spectra displayed a correlation between tautomeric state, primarily driven by halogen identity, coordination mode with neutral nitrogen favored as Br ≪ Cl < F. The state 6-Cl-2-HOpy is influenced metal ion concentration (M) lactam increasing M increases. Compound 1 F–F contacts less...

Pendent proton donor relays in molecular Mn catalysts for dioxygen reduction kinetically favor hydrogen peroxide as a product, however, buffering the with its conjugate base shifts mechanism to bimolecular pathway produce water.

Systems that possess open- and closed-shell behavior attract significant attention from researchers due to their inherent redox charge transport properties. Herein, we report the synthesis of first diborepin biradicals. They display tunable biradical character based on steric electronic profile stabilizing ligand resulting geometric deviation core planarity. While there are numerous all-carbon-based systems, boron-based compounds comparatively rare, particularly ones in which radical sites...

N-Heterocyclic carbenes have numerous applications in synthetic chemistry. We detail the reactivity and chemistry of these molecules including investigations into their reactions with small reagents, use for preparation polarised azines potential application as NLO materials. The imidazolium salts, which are related to NHCs by addition a proton, is also discussed. New ionic liquids revealed.

Abstract Thermolysis of the iron(IV) nitride complex [PhB( t BuIm) 3 FeN] with styrene leads to formation high‐spin iron(II) aziridino Fe‐N(CH 2 CHPh)]. Similar aziridination occurs both electron‐rich and electron‐poor styrenes, while bulky styrenes hinder reaction. The CHPh)] acts as a synthon, reacting generate their corresponding complexes, that is, aziridine cross‐metathesis. Reaction Me SiCl releases N‐functionalized SiN(CH CHPh) simultaneously generating FeCl]. This closes synthetic...

The first examples of N-heterocyclic carbene (NHC) and cyclic(alkyl)(amino) (CAAC) stabilized borepinium borafluorenium heterocycles are reported herein. optical properties the heterocyclic borenium cations were tuned by varying Lewis base changing number atoms in ring. More importantly, functionalizing cationic boron ring system NHC-borafluorenium cation affords a temperature-sensitive molecule with reversible colorimetric "turn off/turn on" solution. Notably, this is report thermochromism...