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Ethylene (ET) is an important gaseous plant hormone. It is highly desirable to develop fluorescent probes for monitoring ethylene in living cells. We report an efficient RhIII-catalysed coupling of N-phenoxyacetamides to ethylene in the presenc

To expand the toolbox for the synthesis of ortho-phenolic sulfilimines, sigmatropic rearrangements were introduced to the field of sulfilimine chemistry. Herein we report a N-H sulfenylation/[2,3]-sigmatropic rearrangement cascade reaction. This mild reaction enables commercially available thiols to serve as the sulfenylation reagent and generates water as the sole byproduct. Moreover, the reaction has a wide substrate scope and can be conducted on a gram scale with excellent reaction efficiency.

Cyclopropane rings are a prominent structural motif in biologically active molecules. Enantio- and diastereoselective construction of cyclopropanes through C?H activation of arenes and coupling with readily available cyclopropenes is highly appealing but

A cascade [3 + 2] annulation and ring opening of N-aryloxyacetamides with 1-alkynylcyclobutanols via Rh(III)-catalyzed redox-neutral C-H/C-C activations using internal oxidative O-NHAc and -OH as the dual directing groups has been achieved. This reaction provided an efficient and regioselective approach to benzofuran derivatives with good functional group compatibility and high yields.

Here in we report, rhodium(III)-catalyzed decarboxylative acylation of arenes using α-oxocarboxylic acids as acyl surrogate. In this strategy, O–NHAc group act as an autocleavable oxidizing directing group (ODGauto), thus giving rise to ortho-acylated phenols in moderate to good yields. Mechanistic studies provided strong support for a kinetically relevant C–H bond activation. According to the best of our knowledge, this is the first report of Rhodium catalyzed decarboxylative acylation.

Herein, a cascade [3 + 2] annulation of N-aryloxyacetamides with 3-(hetero)arylpropiolic acids affording benzofuran-2(3H)-ones via rhodium(iii)-catalyzed redox-neutral C-H functionalization/isomerization/lactonization using an internal oxidative directing group O-NHAc was achieved. This catalytic system provides a regio- and stereoselective approach to synthesize (Z)-3-(amino(aryl)methylene)benzofuran-2(3H)-ones with exclusive Z configuration selectivity, acceptable yields and good functional group tolerance. Preliminary investigations on ultraviolet-visible and fluorescence behaviors reveal that the annulation products may be applied as a promising fluorescent probe for sensing metal cations, especially for cerium (Ce3+).

A Rh(III)-catalyzed unsymmetrical C-H alkylation and amidation of N-phenoxyacetamides with diazo compounds has been developed under mild and redox-neutral conditions, producing dinitrogen as the only byproduct. The reaction represents the first example of one-step, unsymmetrical difunctionalization of two ortho-C-H bonds. Experimental and computational studies support that N-phenoxyacetamides most likely undergo an initial ortho-C-H alkylation with diazo compounds via a Rh(III)-catalyzed C-H activation, and the resulting Rh(III) intermediate subsequently undergoes an intramolecular oxidative addition into the O-N bond to form a Rh(V) nitrenoid species that is protonated and further directed toward electrophilic addition to the second ortho position of the phenyl ring. This work might provide a new direction for unsymmetrical C-H difunctionalization reactions in an efficient manner.

A Rh(III)-catalyzed cascade [3 + 2] annulation of N-phenoxyacetamides with propiolates under mild conditions using the internal oxidative O-N bond as the directing group has been achieved. This catalytic system provides a regio- and stereoselective access to benzofuran-2(3H)-ones bearing exocyclic enamino motifs with exclusive Z configuration selectivity, acceptable to good yields and good functional group compatibility. Mechanistic investigations by experimental and density functional theory studies suggest that a consecutive process of C-H functionalization/isomerization/lactonization is likely to be involved in the reaction.

A combination of Cp*RhIII-catalyzed C?H activation and Wagner–Meerwein-type rearrangement was successfully achieved for the first time. Thus, bridged polycyclic molecules that are not readily accessible by other means were accessed under mild c

A Cp*RhIII-catalyzed annulative carbooxygenation of challenging 1,1-disubstituted alkenes triggered by C?H activation of N-aryloxyacetamides has been established, which affords 2,3-dihydrobenzofuran derivatives with a quaternary carbon center i

A bicyclic olefin was discovered as a cocatalyst in a Cp?Rh(III)-catalyzed C-H bond amidation proceeding by an intramolecular amide transfer in N-phenoxyacetamide derivatives. Combining experimental and theoretical studies, we propose that the olefin promotes a Rh(III) intermediate to undergo oxidative addition into the O-N bond to form a Rh(V) nitrenoid species and subsequently direct the nitrenoid to add to the ortho position. The amide directing group plays a dual role as a cleavable coordinating moiety as well as an essential coupling partner for the C-H amidation. This methodology was successfully applied to the late-stage diversification of natural products and a marketed drug under mild conditions.

Reported herein is the first example of a transition-metal-catalyzed internal oxidative C-H/C-H cross-coupling between two (hetero)arenes through a traceless oxidation directing strategy. Without the requirement of an external metal oxidant, a wide range of phenols, including phenol-containing natural products, can undergo the coupling with azoles to assemble a large library of highly functionalized 2-(2-hydroxyphenyl)azoles. The route provides an opportunity to rapidly screen white-light-emitting materials. As illustrative examples, two bis(triphenylamine)-bearing 2-(2-hydroxyphenyl)oxazoles, which are difficult to access otherwise, exhibit bright white-light emission, high quantum yield, and thermal stability. Also presented is the first example of the white-light emission, in a single excited-state intramolecular proton transfer system, of 2-(2-hydroxyphenyl)azoles, thus highlighting the charm of C-H activation in the discovery of new organic optoelectronic materials.

Herein, we report an unprecedented regioselective and entirely atom-economic cobalt(III)-catalyzed method for the non-annulative, intermolecular carboamination of alkenes. The methodology enables the direct synthesis of unnatural amino acid derivatives an

Here we report a new and mild Rh(iii)-catalyzed and alcohol-involved carbenoid C-H insertion into N-phenoxyacetamides using α-diazomalonates. This reaction provided a straightforward way for installing both an α-quaternary carbon center and a free-OH moiety into the phenyl ring, thus giving access to useful 2-(2-hydroxyphenyl)-2-alkoxymalonates with good substrate/functional group tolerance. This journal is

An efficient Rh(iii)-catalyzed coupling reaction of N-phenoxyacetamides with α,β-unsaturated aldehydes to give 1,2-oxazepines via C-H activation/[4+3] annulation has been developed. This transformation does not require oxidants and features C-C/C-N bond formation to yield seven-membered oxazepine rings at room temperature. Further derivation of 1,2-oxazepines leads to important chroman derivatives. This journal is

Give it a tweak: A novel oxidizing directing group was developed for a rhodium(III)-catalyzed C-H functionalization of N-phenoxyacetamides with alkynes. A small change in the reaction conditions leads to either ortho-hydroxyphenyl-substituted enamides or cyclization to deliver benzofurans with high selectivity (see scheme; Cp=C5Me5). Copyright

By using an oxidizing directing group, a mild, efficient Rh(III) catalyzed C-H olefination reaction between N-phenoxyacetamides and alkenes was developed. This reaction provided a straightforward way for the synthesis of ortho-alkenyl phenols, and the directing group is traceless in the product.

The parallel synthesis of O-aryloxyamines remains an unfulfilled need in the field of medicinal chemistry and fragment-based approaches. To fill this gap a solution-phase two-step process based on (1) a copper-catalyzed cross-coupling of aryl boronic acid

A series of new structural benzoylphenylureas (BPUs) containing oxime ether and oxime ester group were designed and synthesized. The larvicidal activities against Oriental armyworm and mosquito of these benzoylphenylureas were evaluated and the result of bioassay displayed specific structure-activity relationship (SAR). Most of the compounds exhibited excellent larvicidal activities against Oriental armyworm and mosquito. Interestingly, some compounds showed different structure-activity relationship towards diamondback moth, beet armyworm, and corn borer although three tested insects all belong to the same insect order.

A new synthetic method for the preparation of benzofurans has been developed. The key step of this method is the [3,3]-sigmatropic rearrangement of N-trifluoroacetyl-ene-hydroxylamines, which was triggered by acylation of oxime ethers. TFAA has been proved to be the best reagent to induce [3,3]-sigmatropic rearrangement for the synthesis of cyclic or acyclic dihydrobenzofurans. On the other hand, the TFAT-DMAP system is found to be the most effective for constructing various benzofurans. Synthetic utility of this reaction is demonstrated by the short synthesis of natural benzofurans without protection of the hydroxy group. The synthesis of Stemofuran A was accomplished via condensation of ketones with aryloxyamine and subsequent reaction with TFAT-DMAP in a four-step synthesis with 72% overall yield. Similarly, Eupomatenoid 6 and Coumestan were synthesized through the reaction of oxime ether with TFAT-DMAP. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.

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