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High-valent cyclopentadienyl cobalt catalysis is a versatile tool for sustainable C?H bond functionalizations. To harness the full potential of this strategy, control of the stereoselectivity of these processes is necessary. Herein, we report highly enant

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.

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.

Organic sulfur compounds have broad applications in biology, medicine and material sciences and intensive efforts have been devoted to developing mild and general C–S bond-forming methods. However, a mild, transition-metal-free, direct C–H bond functionalization method remains elusive. Here, we report the use of an internal oxidant-directing strategy to achieve this goal. The cascade reactions described here show excellent chemoselectivity and a wide substrate scope for both oxyamines and sulfenylation reagents. This study enlarges the synthesis toolbox for preparing structurally diverse sulfilimines under mild conditions.

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.

The synthesis of heterocycles relies heavily on diverse sigmatropic rearrangements triggered by the cleavage of X-Y (X, Y = C, O, N, S, I) bonds. However, a unified rearrangement approach for constructing heterocyclic libraries is highly desirable. Encouraged by computational analysis of [3,3]-sigmatropic rearrangements, we can now rapidly synthesize oxa-heterocycles by treating N-phenoxyacetamides (Ph-ONHAc) with compounds containing an sp-hybridized carbon. The generality of the process is illustrated by the late-stage diversification of natural products, including estrone and an approved drug. A combination of experimental and computational studies revealed that the reactions proceed through a facile Claisen-like [3,3]-sigmatropic rearrangement/annulation process.

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 cobalt(III)-catalyzed, redox-neutral, intermolecular carboamination of propiolates and bicyclic alkenes was developed. This non-annulative coupling strategy features atom economy, high regioselectivity, good yields, and functional groups tolerance. Such a carboamination reaction was applied to modified phenols from the corresponding phenols under mild conditions.

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 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.

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

The invention discloses a 1,2-oxa-cyclic compound derivative and a preparation method thereof. A molecular structural general formula of 1,2-oxa-cyclic compound derivative is (I), wherein in the formula, A is (hetero) aromatic ring or non-aromatic ring; R

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

Considerable efforts have been devoted to the development of highly efficient blue light-emitting materials. However, deep-blue fluorescence materials that can satisfy the Commission Internationale de l'Eclairage (CIE) coordinates of (0.14, 0.08) of the N

An efficient rhodium(III)-catalyzed coupling reaction of N-aryloxyacetamides with 6-diazo-2-cyclohexenones through a cascade redox-neutral C–H functionalization and aromatization has been developed. This novel and scalable transformation provides a straightforward way to construct unsymmetrical ortho-biphenols with broad substrate scope under mild and redox-neutral conditions. The synthetic utility of this approach is demonstrated in the late-stage functionalization of bioactive compounds and the synthesis of an optically active ortho-biphenol. (Figure presented.).

A Rh(iii)-catalyzed C-H alkynylation of substituted N-phenoxyacetamides has been developed with the aid of hypervalent iodine-alkyne reagents. Complementary to the Sonogashira coupling reaction, this protocol provides an efficient and straightforward method to access aryl alkynes at room temperature. The multifunctional directing group is preserved which can be further employed for ortho-directed functionalizations to obtain additional new complex products.

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.

A Rh-Cu bimetallic catalyzed o-acylation of acyloxacetamide with alkynes has been described. This transformation provides a novel, concise way to synthesize ortho-acylphenols using functionalized alkynes as acylating reagents. Mechanistic studies revealed a Rh-Cu relay process, in which O2 plays a critical role for the formation of carbonyl compounds.

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

The development of photoredox reactions of aryloxy-amides for the generation of amidyl radicals and their use in hydroamination-cyclization and N-arylation reactions is reported. Owing to the ease of single-electron-transfer reduction of the aryloxy-amides, the organic dye eosin Y was used as the photoredox catalyst, which results in fully transition-metal-free processes. These transformations exhibit a broad scope, are tolerant to several important functionalities, and have been used in the late-stage modification of complex and high-value N-containing molecules.

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.