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Recently, we have reported a systematic study of photoinduced electron-transfer reactions in ionic liquid solvents using neutral and anionic electron donors and a series of cyano-substituted anthracene acceptors [Wu, B.; Maroncelli, M.; Castner, E. W., Jr.Photoinduced Bimolecular Electron Transfer in Ionic Liquids. J. Am. Chem. Soc.139, 2017, 14568]. Herein, we report complementary results for a cationic class of 1-alkyl-4-dimethylaminopyridinium electron donors. Reductive quenching of cyano-substituted anthracene fluorophores by these cationic quenchers is studied in solutions of acetonitrile and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Varying the length of the alkyl chain permits tuning of the quencher diffusivities in solution. The observed quenching kinetics are interpreted using a diffusion-reaction analysis. Together with results from the prior study, these results show that the intrinsic electron-transfer rate constant does not depend on the quencher charge in this family of reactions. [ABSTRACT FROM AUTHOR]

Synthetic siRNA has been considered as a highly promising therapeutic agent for human diseases. However, clinical use of siRNA has been hampered by instability in the body and inability to deliver sufficient RNA interference compounds to the tissues or cells. To address this challenge, we present here a single siRNA nanocapsule delivery technology, which is achieved by encapsulating a single siRNA molecule within a degradable polymer nanocapsule with a diameter around 20 nm and positive surface charge. As proof-of-concept, since CCR5 is considered a major silencing target of HIV therapy, CCR5-siRNA nanocapsules were delivered into 293T cells and successfully downregulated the CCR5 RNA fused with mCherry reporter RNA. In the absence of human serum, nanocapsules and lipofectamine silenced expression of CCR5-mCherry expression to 8% and 15%, respectively. Such nanocapsules maintain the integrity of siRNA inside even after incubation with ribonuclease and serum for 1 h; under the same conditions, siRNA is degraded in the native form or when formulated with lipofectamine. In the presence of serum, CCR5-siRNA nanocapsules knocked down CCR5-mCherry expression to less than 15% while siRNAs delivered through lipofectamine slightly knocked down the expression to 55%. In summary, this work provides a novel platform for siRNA delivery that can be developed for therapeutic purposes. [ABSTRACT FROM AUTHOR]

Steady-state absorption and emission and femtosecond time-resolved emission spectroscopy of two benzylidene malononitriles, 2-[4-(dimethylamino)benzylidene])malononitrile (DMN) and julolidinemalononitrile (JDMN), are reported in a variety of room-temperature solvents. Solvatochromic shifts of these molecules are consistent with dielectric continuum descriptions and an S1−S0dipole moment change of 8.5 D. Time-resolved spectra show modest dynamic Stokes shifts of ∼1000 cm−1occurring independently of fluorescence decay, which takes place in 0.5−5 ps in most room-temperature solvents. Absorption transition moments and fluorescence decay times are used to determine radiative rate constants: krad= 0.32 ± 0.02 ns−1in DMN and 0.28 ± 0.02 ns−1in JDMN, assumed to be independent of solvent. Quantum yield data together with these radiative rates provide the reaction rate constants krxnassociated with the internal conversion process of these molecules in 33 representative solvents at 298 K and in several solvents as functions of temperature. Reaction rates of JDMN are systematically lower than those of DMN by a factor of 2.0. Values of krxnin series of homologous solvents or in a single solvent at different temperatures are correlated to solvent viscosity η and temperature Tin the manner krxn/T∝ η−pwith exponents 0.2 ≤ p≤ 0.8. Solvent polarity appears to influence these reactions such that for a given viscosity reaction in high polarity solvents is significantly slower than in nonpolar solvents. However, this conclusion is predicated on the assumption that reactive friction is identical in solvents of the same viscosity, which is unlikely to be quantitatively correct. The observed reaction rates and their solvent dependence are discussed in terms of isomerization about the CC bond occurring on a shelf-like potential. [ABSTRACT FROM AUTHOR]

A boron trihalide mediated alkyne-aldehyde coupling reaction leading to stereodefined 1,3,5-triaryl-l,5- dihalo-1,4-pentadienes is described. The study led to the discovery of a direct substitution of hydroxyl groups by stereodefined alkenyl moieties using alkenylboron dihalides. During the investigation, it was also discovered that, at low temperatures, the reaction of BCI3 with alkynes produces monovinylboron dichioride rather than the reported divinylboron chloride. A modified reaction mechanism for the boron trichloride mediated alkyne-aldehyde coupling reaction is now proposed. The reaction temperature and mode of addition have been found to have dramatic affects on the stereochemistry of the diene products. [ABSTRACT FROM AUTHOR]

A new unusual pigment with a novel carbon framework named selaginellin (1) was isolated from the acetone extract of Selaginella sinensis, and its methoxy derivative (1a) was synthesized. Both selaginellin 1 and la are racemic com- pounds. The structure of selaginellin 1 was established as (R,S)-4-[(4′-hydroxy-4-(hydroxymethyl)-3-((4-hydroxyphenyl)ethynyl)biphenyl-2-yl)(4-hydroxyphenyl)methylenel-2,5-cyclohexadien-1-one and la as (R,S)-4-[(4′-methoxy-4-(methoxymethyl)-3-((4-methoxyphenyl)ethynyl)biphenyl-2-yl)(4-methoxyphenyl)methylenel-2,5-cyclohexadien-1-one by the analysis of one- and two-dimensional NMR data, HR-ESIMS, El-MS. IR, UV, CD, and single-crystal X-ray experiments, and the mechanism of their color change according to different pH values and fluorescent properties was studied. [ABSTRACT FROM AUTHOR]

A novel boronated aminocyclobutanecarboxylic acid (1) was synthesized for potential use in boron neutron capture therapy. Starting from the readily available 3-(bromomethyl)cyclobutanone ketal (4), several synthetic routes to I were evaluated. After several unsuccessful attempts with traditional synthetic methods, a novel synthetic strategy to generate the new boronated cyclic amino acid was developed. The tolerance of the hydantoin group to the selenoxide elimination reaction conditions in the preparation of alkenyl compound 7 proved to be the key step in the new strategy. [ABSTRACT FROM AUTHOR]

Alkoxide C−O bond cleavage occurs readily at room temperature in the presence of titanium(IV) halide. Capture of the resultant carbocation by alkynes provides an efficient route to trisubstituted (E)-alkenyl halides with high stereoselectivity. [ABSTRACT FROM AUTHOR]

An alternate reaction mechanism for the boron tribromide mediated deprotection of aryl propargyl ethers based on the isolation of a key boron-containing byproduct is proposed. On the basis of the new mechanistic insight, we discovered that HBBr2·SMe2 can also be used for cleaving aryl propargyl ethers. [ABSTRACT FROM AUTHOR]

Iron trichloride was found to cleave carbon−oxygen bonds in a variety of lithium alkoxides at room temperature. Other Lewis acids were also found to cleave the alkoxides. Acid-sensitive groups are tolerated under the reported reaction conditions. [ABSTRACT FROM AUTHOR]

Introduces a convenient approach to 4-substituted 2(5H)-furanones. Effects of solvent and base on the coupling of trans-pentylcyclopropylboronic acid with beta-tetronic acid triflate; Account on the coupling reaction of boronic acids with beta-tetronic acid triflate; Properties of compounds containing 2(5H)-furanone moiety.

The article analyzes the stabilities of benzylic, allylic, and propargylic cabocations. These cations from alkoxides are well-documented and have been the subject of several theoretical and experimental studies. However, due to the strong acidic conditions required, the availability of these cations has not resulted in their general use as synthetic intermediates.

Pharmaceutically interesting, angular bis-benzimidazoles with three appendages have been synthesized successfully through a diversity-oriented approach with soluble support under microwave irradiation. Polymer immobilized o-phenylenediamine was selectively N-acylated with 2-chloro-3-nitrobenzoic acid in a primary aromatic amino moiety. The obtained amide was cyclized to benzimidazole in an acidic condition, and subsequently nucleophilic aromatic substitution with different amines was performed. Successive reduction, cyclization with various aldehydes and activated isothiocyanates yielded angular biheterocyclic benzimidazoles in good quantities. Reaction progress on polymer support was precisely monitored using the conventional proton NMR spectroscopy. Preliminary screening results showed some of these interesting compounds exhibited moderately to good inhibition against vascular endothelial growth factor receptor 3 (VEGFR-3), which is related to invasion and migration of cancer cells. [ABSTRACT FROM AUTHOR]

A novel iron-catalyzed intermolecular decarboxylative Csp3−Csp2coupling reaction using proline derivatives as starting materials is developed. In this process, a series of potentially useful ligands (tertiary aminonaphthol) for catalysis was obtained. [ABSTRACT FROM AUTHOR]

Pt electrocatalysts supported on multiwalled carbon nanotube (Pt/MWCNT) nanocomposites have been synthesized by a rapid intermittent microwave irradiation (IMI) technique for polymer electrolyte and direct methanol fuel cells (PEFCs and DMFCs), using H2PtCl6 as Pt precursor. The Pt/MWCNT nanocomposites are characterized by XRD, XPS, and TEM. The results indicate that Pt particle size and distribution on the MWCNT support are affected significantly by the oxidation treatment of MWCNTs, the IMI procedure, and the MWCNT tube diameter or surface area. The PtOx (x = 1, 2) species was first deposited on the surface of MWCNTs by the IMI and subsequently reduced to Pt(0) with refluxing in the presence of HCOOH. Pt/MWCNT nanocomposites synthesized by this IMI method have achieved extremely uniform dispersed Pt nanoparticles with a particle size of ∼3 nm. Electrochemical measurement indicates that Pt/MWCNT nanocomposites synthesized by the IMI method display a significantly higher electrochemically active area and higher catalytic activity for the methanol oxidation reaction in comparison to a commercial Pt/C catalyst. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed tandem C--H activation/biscyclization reaction of propargylic carbonates with terminal alkynes was determined, which allowed the tetracyclic benz[a]anthracene framework to be constructed with high regioselectivity. A possible mechanism for this tandem C--H activation/biscyclization process was discussed. [ABSTRACT FROM AUTHOR]

A novel method for the construction of 2,3-dihydro-5-iodopyran-4-one through a domino cyclization/migration reaction of 1-alkynyl-2,3-epoxy alcohol was developed. Wet solvent is essential for this reaction. The resulting iodine- containing product can be readily elaborated to more complex products by using known organopalladium chemistry. [ABSTRACT FROM AUTHOR]

Allylic sulfones were synthesized with excellent selectivity and good yield via Pd-catalyzed cross-coupling of vinyl iodide with N-tosylhydrazone. This process involves palladium carbene migratory insertion/trapping with sulfinic acid salts. For the previous Pd-catalyzed N-tosylhydrazone cross-coupling, sulfinic acid salt is generated as a byproduct. In this transformation, the diazo compound and the sulfinic acid salt, which are all generated from N-tosylhydrazone, were used as cross-coupling partner. [ABSTRACT FROM AUTHOR]

An efficient palladium-catalyzed dearomatizing [2+2+1] carbocyclization of 1,7-enynes with iodophenols has been developed. A type of tetracyclic scaffold was built in this reaction, exhibiting a broad substrate scope with moderate to excellent yields. More importantly, this method provides a potential strategy for the synthesis of tetracyclic skeleton natural products. [ABSTRACT FROM AUTHOR]

A novel copper(II) trifluoromethanesulfonate-catalyzed, high-efficiency, and atom-economical synthesis of valuable organophosphorus compounds via cascade annulation of propargylic alcohols with diphenylphosphine oxide is described. This protocol, which has a good functional-group compatibility and insensitivity to an ambient atmosphere, provides a simple and direct pathway to the products, organophosphorus compounds, in good yields under mild conditions. The method could be efficiently scaled up to gram scale, thus highlighting a potential application of this methodology. [ABSTRACT FROM AUTHOR]

An expedient strategy for the preparation of diiodinated diepoxydibenzo[c,k][1,9]dioxacyclohexadecines from readily available 2-(4-hydroxybut-1-yn-1-yl)benzaldehydes through electrophile-triggered tandem cyclization/intermolecular acetalation sequence has been presented. The electrophilic macrocyclization can be performed under mild conditions and in up to gram quantities. Moreover, palladium-catalyzed coupling and reduction reactions of the resulting iodides could efficiently afford oxa-macrocycles. [ABSTRACT FROM AUTHOR]

A copper-catalyzed oxidative cyclization procedure has been developed for the production of 2-sulfonated 9H-pyrrolo[1,2-a]indol-9-ones via the direct sulfonylation of N-propargyl-substituted indoles with sulfonylhydrazides and tert-butyl hydroperoxide (TBHP). This novel protocol, which tolerates a broad range of functional groups, offers a simple, efficient, and atom-economical route to a series of fluorazones in good yields under mild conditions. [ABSTRACT FROM AUTHOR]

An unprecedented Lewis acid catalyzed, high-efficiency synthesis of valuable 2-(quinolin-2-yl)prop-2-en-1-ones via dehydrogenative coupling of propargylic alkynols with quinoline N-oxides is described. This protocol, which tolerates a broad range of functional groups, provides a straightforward pathway to the products 2-(quinolin-2-yl)prop-2-en-1-one scaffolds in satisfactory yields. The conversion could be scaled up to gram scale efficiently, which underlines a latent application of this methodology. [ABSTRACT FROM AUTHOR]

A facile copper-catalyzed radical aminoarylation of acrylamide with N-fluorobenzenesulfonimide (NFSI) is described. In the presence of copper acetate and 1,10-phenanthroline, a range of isoquinoline-1,3-diones can be constructed in moderate to good yields using NFSI as the amination reagent. Mechanistic studies demonstrated the reaction went through a sequential radical addition and cyclization pathway, which was supported by DFT calculations. [ABSTRACT FROM AUTHOR]

A strategy for the synthesis of 6,9-dihydropyrido[1,2-a]indoles through a cascade iodocyclization of 4-(3-methyl-1H-indol-1-yl)-1,1-diphenylbut-2-yn-1-ol derivatives is presented. This reaction was conducted under very mild conditions and in a short time. The reactions are metal-free, are environmentally friendly and give up to 94% yield. Moreover, the obtained halides allow functional group diversification by palladium-catalyzed coupling reactions, which could act as potential intermediates for the synthesis of valuable compounds. [ABSTRACT FROM AUTHOR]

A highly regio- and stereoselective copper-mediated cyanodifluoroalkylation of alkynes with ethyl difluoroiodoacetate and trimethylsilyl cyanide (TMSCN) is described. The three-component coupling reaction provides straightforward access to a variety of useful difluoroalkyl-substituted acrylonitriles. The introduction of the nitrile unit is of great importance in drug discovery for the modification of this fragment. Preliminary mechanistic investigations indicate that a vinyl iodide intermediate and a difluoroalkyl radical might be involved in this transformation. [ABSTRACT FROM AUTHOR]

A highly diastereoselective dearomatization of indoles via palladium-catalyzed decarboxylative alkynyl termination was developed. This protocol provides dissimilar tetracyclic and tetrasubstituted indoline scaffolds bearing congested stereocenters, which led to operationally simple conditions, short time, and broad substrate scope. Additionally, this reaction system could be scaled to gram quantities in a satisfactory yield and diastereoselectivity. [ABSTRACT FROM AUTHOR]

An unprecedented Lewis acid catalyzed, protection-free, and high-efficiency synthesis of valuable 3,4-dihydro-2H-2,4-methanochromans via cycloaddition of propargylic alkynols with 2-vinylphenol is described. This cycloaddition protocol, which tolerates a wide variety of functional groups, provides practical, versatile, and atom-economical access to a new class of appealing bridged-ring products in satisfactory yields. Compared with the reported reaction conditions for bridged-ring skeletons synthesis, the present reaction conditions are neutral, mild, and without any additives. [ABSTRACT FROM AUTHOR]

A new method for the AgSCF3-mediated radical cascade difunctionalizing trifluoromethythiolation of alkynes with dearomatization is developed. This protocol provides a novel route to SCF3-substituted spirocyclic compounds via the formation of one C-SCF3 bond, one C-C bond, and one C-O double bond in a single step. [ABSTRACT FROM AUTHOR]

An efficient palladium-catalyzed alkylation of electron-deficient polyfluoroarenes is described. The protocol provides a useful and operationally simple access to a broad scope of alkylated polyfluoroarene derivatives in moderate to excellent yields. This also represents the first example of the introduction of a polyfluoroarene structure involving an alkylpalladium(II) intermediate. [ABSTRACT FROM AUTHOR]

A BF3·OEt2-AgSCF3 mediated direct trifluoromethylthiolation/cascade cyclization of propynols involving the SCF3 anion nucleophilic pathway is developed. This protocol also provides an opportunity to construct valuable trifluoromethylthio-substituted 2H-chromene and 1,2-dihydroquinoline systems with high efficiency under mild conditions. Additionally, the developed BF3·OEt2-AgSCF3 reaction system could be scaled up to gram quantities in a satisfactory yield without inert gas protection. [ABSTRACT FROM AUTHOR]

An unprecedented Lewis acid catalyzed [4 + 3] cycloaddition reaction is described that provides a straightforward route to polycyclic products containing an imine-based indole azepine scaffold, starting from readily available internal tertiary alkynols and azides. This cycloaddition protocol provides efficient and atom-economical access to a new class of fascinating imine-containing products in satisfactory yields, which has shown good application in the construction of seven-membered N-heterocycles. [ABSTRACT FROM AUTHOR]

A silver-catalyzed decarboxylative addition/aryl migration/desulfonylation of N-phenyl-N-(phenylsulfonyl)methacrylamide with primary, secondary, and tertiary carboxylic acids was described. The protocol provides an efficient approach for the synthesis of α-all-carbon quaternary stereocenters amides and isoquinolinediones. It was proposed that the radical generated from the silver-catalyzed decarboxylation was involved in the sequence reaction. [ABSTRACT FROM AUTHOR]

A silver-catalyzed decarboxylative addition/aryl migration/desulfonylation of N-phenyl-N-(phenylsulfonyl)methacrylamide with primary, secondary, and tertiary carboxylic acids was described. The protocol provides an efficient approach for the synthesis of α-all-carbon quaternary stereocenters amides and isoquinolinediones. It was proposed that the radical generated from the silver-catalyzed decarboxylation was involved in the sequence reaction. [ABSTRACT FROM AUTHOR]

An iodine-promoted one-pot radical cyclization reaction of 1,6-enynes with sulfonyl hydrazides to provide five-membered and hexatomic ring sulfonylated products under the same conditions is established. This reaction proceeded smoothly in water and gave the corresponding products by using I2/TBHP instead of expensive and toxic catalysts with C-S and C-I bond formed in one step. This method also allowed easy access to significant functional sulfones for potential applications in medicinal and organic chemistry. [ABSTRACT FROM AUTHOR]

A palladium-catalyzedaryldifluoroalkylation of alkynes with ethyl difluoroiodoacetate andarylboronic acids as reaction partners is described. The alkyne difunctionalizationprocess provides various aryldifluoroalkylated products in one potunder mild reaction conditions. A wide range of alkynes and diversearylboronic acids are compatible with these reaction conditions. Highreaction efficiency and broad substrate scope are the notable featuresof this transformation. Preliminary mechanistic investigations indicatethat a difluoroalkyl radical addition pathway is involved in thistransformation. [ABSTRACT FROM AUTHOR]

We have developed a highly selective method for the synthesis of α,β-unsaturated amides and alkenyl nitriles from readily available propargylic alcohols. The reaction proceeded smoothly under the neutral conditions with hydroxylamine hydrochloride (NH2OH·HCl) as the nitrogen source. The development of these new strategies has significantly extended the application of hydroxylamine hydrochloride to the chemistry of propargylic alcohols. Moreover, both secondary and tertiary alcohols have been highly regioselectively transformed to the desired products with good functional group compatibility. [ABSTRACT FROM AUTHOR]

A AgSCF3-mediated radical cascade cyclization/trifluoromethylthiolationof 1,6-enynes triggered by a C–C triple bond is developed.This protocol also provides another opportunity to construct a valuabletrifluoromethylthio-substituted polycyclic fluorene system throughthe formations of one C–SCF3bond and two C–Cbonds in a single step. [ABSTRACT FROM AUTHOR]

An efficient cinchona alkaloid-derived amine catalyzed asymmetric [4 + 2] cycloaddition is successfully developed. 4H-Pyran fused pyrrolin-2-one products are readily obtained in moderate to high yields with good enantioselectivites by employing allene ketones and 2,3-dioxopyrrolidine derivatives as substrates. [ABSTRACT FROM AUTHOR]

Vinylogous reactivity of olefinicazlactones was realized throughthe development of a chiral amine-catalyzed highly stereoselectiveallylic–allylic alkylation with Morita–Baylis–Hillmancarbonates. The Lewis base activation of electrophile and Brønstedbase activation of nucleophile were efficiently combined, giving accessto multifunctional acyclic α-amino acid derivatives in a highlystereocontrolled manner. The synthetic utility of these versatilesynthons was further demonstrated by the facile synthesis of protectedcyclic quaternary α-amino acids. [ABSTRACT FROM AUTHOR]

A strategy for the synthesis of iodocarbazoles through a tandem iodocyclization with migration and aromatization is presented. This sequential cascade process is concisely conducted at room temperature and in a short time. Moreover, the obtained halides can be further applied to palladium-catalyzed coupling reactions, which act as the important intermediates for building other valuable compounds. [ABSTRACT FROM AUTHOR]

An efficient catalytic approach for the synthesis of substituted peroxides, alcohols, and ketones through a catalyst-controlled highly selective dioxygenation of olefins has been demonstrated. The reported methods are mild and practical, can be switched by the selection of different catalytic systems, and employ peroxide as an oxidant and a reagent at room temperature. [ABSTRACT FROM AUTHOR]

A novel BF3⋅Et2O-promoted tandem reaction of easily prepared 2-propynolphenols/anilines and trimethylsilyl azide is developed to give C2-alkenylated benzoxazoles and benzimidazoles in moderate to good yields. Most reactions could be accomplished in 30 min at room temperature. This tandem process involves a Csp-Csp2 bond cleavage and a C-N bond formation. Moreover, both tertiary and secondary propargylic alcohols with diverse functional groups were tolerated under the mild conditions. [ABSTRACT FROM AUTHOR]

A novel and facile oxyazidation of alkenes under metal-free and mild conditions has been reported. A remarkable feature of the developed procedure is consecutive construction of C-O and C-N bonds in one step. The process allows quick and selective assembly of alkyl azide from readily available starting materials, where N-hydroxyphthalimide was used as an oxygen-radical precursor and TMSN3 as the N3 source. A range of aromatic alkenes bearing synthetically useful functional groups was tolerated. [ABSTRACT FROM AUTHOR]

A new method with high efficiency for the synthesis of α,β-unsaturated amides from the easily prepared propargyl alcohols and TMSN3 using TMSCl as an acid promoter is developed. A wide variety of α,β-unsaturated amides were produced in moderate to excellent yields. Mechanistic studies indicate that this transformation involves TMSCl-mediated allenylazide intermediate formation, C-C bond cleavage, and C-N bond formation. Significantly, this reaction shows good functional group compatibility and high regioselectivity, with a relatively short reaction time and inexpensive reagents. [ABSTRACT FROM AUTHOR]

ortho-Aminated vinylarene derivatives were obtained via a reaction of aryl iodides, N-benzoyloxyamines, and N-tosylhydrazones. This approach involves a palladium-catalyzed, norbornene-mediated ortho-amination/N-tosylhydrazone insertion reaction. In this transformation, one C-N bond and one C-C bond are formed and an amine group is introduced at the ortho position successfully. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of (E)-1H-inden-1-ones using gold-catalyzed tandem [3,3]-propargyl ester rearrangement followed by Michael addition under mild reaction conditions has been developed. The resulting products are important frameworks found in numerous natural products and pharmaceutically active compounds, as well as being valuable intermediates in organic synthesis. [ABSTRACT FROM AUTHOR]

Brensted acid catalyzed tandem cyclization was found to be highly effective for the preparation of a series of polysubstituted 4-pyrones from diynones (yield up to 99%). 4-Pyridone and 3-pyrrolone derivatives were also selectively synthesized by employing NTS and/or Bransted acid. NIS as an electrophilic reagent could promote these reactions efficiently and rapidly under very mild reaction conditions [ABSTRACT FROM AUTHOR]

An efficient approach for the synthesis of tetrasubstituted cyclopentadienes through Pd-catalyzed reactions of (Z)-2-en-4-yn acetates with substituted indoles was developed. This methodology has the advantages of broad scope, simple conditions and easily accessible starting materials. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed tandem cyclization/C--H functionalization of two alkynes was accomplished to construct a series of polycyclic functionalized indoles. A range of internal alkynes bearing synthetically useful functional groups were tolerated. A good regioselectivity was observed when alkyl-substituted alkynes were introduced into the reaction system, and a single product was obtained. Molecular oxygen was used as the terminal oxidant in the approach, rendering the reaction more sustainable. [ABSTRACT FROM AUTHOR]

Highly substituted benzene derivatives, including alkoxy-, iodoalkoxy-, and diiodo-substituted benzenes, can be selectively synthesized via Brønsted acid catalyzed and iodine-promoted tandem carbocyclization respectively. This reaction involved a direct process for C--C bond formation from 5,2-enyn-1-ones, and different reaction systems (Brønsted acids/electrophiles with solvents) afforded different substituted benzenes. Furthermore, the halogenated moiety and alkoxy group can be readily introduced into the benzene in a position which has not been easily obtained previously. [ABSTRACT FROM AUTHOR]