Abstract Enolonium species/iodo(III)enolates of carbonyl compounds have been suggested to be intermediates in a wide variety hypervalent iodine induced chemical transformations ketones, including α‐C−O, α‐C−N, α‐C−C, and α‐carbon–halide bond formation, but they never characterized. We report that these elusive umpoled enolates may made as discrete species are stable for several minutes at −78 °C, the first spectroscopic identification such species. It is shown enolonium direct C−O, C−N,...

Chemistry of the Au-S interface at nanoscale is one most complex systems to study, as nature and strength bond change under different experimental conditions. In this using mechanically controlled break junction technique, we probed conductance analyzed Flicker noise for several aliphatic aromatic thiol derivatives thioethers. We demonstrate that can be used unambiguously differentiate between stronger chemisorption (Au-SR) weaker physisorption (Au-SRR') type interactions. The measurements...

The methyl groups in TetMe-IBX lower the activation energy corresponding to rate-determining hypervalent twisting (theoretical calculations), and steric relay between successive twists structure, which manifests significant solubility common organic solvents. Consequently, oxidations of alcohols sulfides occur at room temperature In situ generation reactive from its precursor iodo-acid, i.e., 3,4,5,6-tetramethyl-2-iodobenzoic acid, presence oxone as a co-oxidant facilitates oxidation diverse...

Oxidative cleavage of a variety olefins to the corresponding ketones/carboxylic acids is shown occur in facile manner with 3,4,5,6-tetramethyl-2-iodobenzoic acid (TetMe-IA)/oxone. The simple methodology involves mere stirring olefin and catalytic amount (10 mol %) TetMe-IA oxone acetonitrile-water mixture (1:1, v/v) at rt. reaction mechanism initial dihydroxylation oxone, oxidative by situ-generated 3,4,5,6-tetramethyl-2-iodoxybenzoic (TetMe-IBX), oxidation aldehyde functionality oxone....

Herein it is shown, for the first time, that enolonium species are powerful electrophiles capable of reacting with aromatic compounds in an intermolecular manner to afford α-arylated ketones. The reaction compatible a variety functional groups, wide scope respect and ketone, even works polymerization-prone substrates such as substituted pyrroles, thiophenes, furans. Only 1.6 5 equiv commodity needed.

We designed and synthesized λ(5)-cyclic periodinanes 1 2, which are homologous to IBX (1-hydroxy-1-oxo-1H-1λ(5)-benzo[d][1,2]iodoxol-3-one) by one carbon, thwart close packing of molecules in the crystal lattice permit solubility common organic solvents facilitate oxidations with enhanced reactivity. The X-ray structures revealed that both 2 exist solid state as pseudocyclic (PC) acids, i.e., 1PC 2PC, less weakly associated compared those parent due twisting introduced via sp(3) benzylic...

Enolonium species, resulting from the umpolung of ketone enolates by Koser's hypervalent iodine reagents activated boron trifluoride, react with a variety nitrogen heterocycles to form α-aminated ketones. The reactions are mild and complete in 4–5 h. Additionally, α-azidation enolonium species takes place using trimethylsilyl azide as convenient source nucleophile.

Abstract Enolonium species/iodo(III)enolates of carbonyl compounds have been suggested to be intermediates in a wide variety hypervalent iodine induced chemical transformations ketones, including α‐C−O, α‐C−N, α‐C−C, and α‐carbon–halide bond formation, but they never characterized. We report that these elusive umpoled enolates may made as discrete species are stable for several minutes at −78 °C, the first spectroscopic identification such species. It is shown enolonium direct C−O, C−N,...

Due to their closely matched reactivity, the coupling of two dissimilar ketone enolates form a 1,4-diketone remains challenge in organic synthesis. We herein report that umpolung trimethylsilyl enol ether (1 equiv) discrete enolonium species, followed by addition as little 1.2-1.4 equivalents second ether, provides an attractive solution this problem. A wide array may be used products 38 74% yield. use TMS ethers precursors, optimization cross-coupling should include investigating order addition.

Dioxiranes are extremely useful multitasking agents for a broad spectrum of chemical transformations. This review collates the history dioxiranes over last fifty years in realm organic and materials chemistry.

The effect of diverse intramolecular connectivity on the photophysical and hole-transporting attributes was studied for six butterfly-shaped π-functionalized 1,5-diazocines (Dzs). These molecules were developed by slight structural tweaking the...

A simple procedure for the synthesis of a variety o-carboxyarylacrylic acids has been developed with Oxone (2KHSO5·KHSO4·K2SO4); oxidation reaction involves stirring methoxy/hydroxy-substituted naphthalenes, phenanthrenes, anthracenes, etc. in an acetonitrile-water mixture (1:1, v/v) at rt. Mechanistically, proceeds via initial naphthalene to o-quinone, which undergoes cleavage corresponding acid. The higher aromatics are found yield carboxymethyl lactones derived from initially formed acids.

Improved understanding of charge-transport in single molecules is essential for harnessing the potential molecules, e.g., as circuit components at ultimate size limit. However, interpretation and analysis large, stochastic data sets produced by most quantum transport experiments remain an ongoing challenge to discovering much-needed structure–property relationships. Here, we introduce segment clustering, a novel unsupervised hypothesis generation tool investigating molecule break junction...

The rational design of single-molecule electrical components requires a deep and predictive understanding structure–function relationships. Here, we explore the relationship between chemical substituents conductance metal–single-molecule–metal junctions, using functionalized oligophenylenevinylenes as model system. Using combination mechanically controlled break-junction experiments various levels theory including non-equilibrium Green's functions, demonstrate that connection gas-phase...

Regioisomeric photochromic chromenes 1Ch-6Ch substituted with the (2,3,4,5,6-pentamethyl/phenyl)phenyl scaffold were designed to delve into stereoelectronic effects on spectrokinetic properties of photogenerated o-quinonoid reactive intermediates. While latter derived from 1Ch, 2Ch, 4Ch, and 5Ch found exhibit notable persistence, those 3Ch 6Ch revert rapidly at room temperature preclude visible coloration. The intermediates 1Ch 2Ch be marginally more stable than 4Ch 5Ch, respectively,...

Abstract The reagent system Oxone ® /NaHCO 3 is shown to be very convenient for direct conversion of thiols sulfonic acids. simple procedure that involves stirring thiol, in CH CN‐H 2 O (3:2, v/v) mixture at 20±5 °C allows access a variety aliphatic as well electron rich and deficient aromatic oxidation also occur with KBrO , albeit over longer durations. mechanism thiol‐to‐sulfonic acid proposed proceed via transfer steps, which supported by the formation disufide low conversions.

Remarkable modulation of the persistence photogenerated colored o-quinonoid intermediates via a through-space interaction has been demonstrated in chromenes 1–4 based on 1,8-diarylnaphthalenes. Polar/π is shown to stabilize closed form 4 such an extent that photoinduced coloration virtually invisible, while same stabilization opened 2 permits ready with long-lived intermediate.