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A variety of 2-substituted 3-selanyl-chromenones are readily prepared through a cascade selanylation/cyclization of alkynyl aryl ketones with sulfonoselenoates. This transformation is performed under metal-free conditions and does not require an additional oxidant. It also has the advantage of broad functional group tolerance and scalability. [ABSTRACT FROM AUTHOR]

Oxetanes, 4-membered oxygen-containing heterocycles, were identified to have pharmaceutical applications after the discovery of the chemotherapeutic drug taxol (Paclitaxel) and its analogues. Furthermore, oxetanes have been identified as bioisosteres for several common functional groups and are present in a number of natural products. However, oxetanes are one of the least common oxygen-containing heterocycles in active pharmaceutical ingredients on the market, which can be attributed, in part, due to challenges with their synthesis. Previous strategies rely on nucleophilic substitutions or [2+2]-cycloadditions, but are limited by the stepwise buildup of starting material and limitations in scope resulting from requirements for activated substrates. To address these limitations, we envisioned activating simple carbonyls to their corresponding α-oxy iodides to promote ketyl radical formation. These radicals can then undergo atom-transfer radical addition with alkenes followed by one-pot nucleophilic substitution to produce oxetanes. Herein, we present a proof-of-principle of this strategy in which fluoroalkyl carbonyls are successfully converted into the corresponding fluoroalkyl oxetanes. [ABSTRACT FROM AUTHOR]

A seven-step ex-chiral-pool synthesis of optically active 4-alkylidenetetrahydroisoquinolines was developed. Starting from 6-bromopiperonal and (S)-serine esters, N -benzylation via reductive amination gave enantiopure N -piperonyl serine esters. Subsequent NH and OH protection delivered defined (S)-serine building blocks. The best results to achieve the conversion into the corresponding serinal were obtained via a two-step sequence of NaBH4 /LiCl reduction and subsequent TEMPO oxidation. Then, chain elongation using the Masamune–Roush variant of the Horner olefination afforded ethyl (E)-4-(N -6-bromopiperonyl)-substituted pentenoates in high yields. Intramolecular Heck cyclization employing the Herrmann–Beller catalyst enabled generation of enantiopure 4-(2-ethoxycarbonylmethylidene)tetrahydroisoquinoline building blocks in high Z -selectivity. Subsequent selected functional group transformations gave carbinols and lactones, which can be used as key intermediates in crinane alkaloid total syntheses. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed one-pot amino-sulfonylation of aryl iodide derivatives with thiourea dioxide, PdCl2 dppf, and one-pot added hydroxylamine- O -sulfonic acid is presented. This amino-sulfonylation gave structure diversity to aryl primary sulfonamides and features good functional group compatibility, mild reaction conditions, excellent regioselectivity, and moderate to good yields. The robustness and potential of this method have also been successfully demonstrated by late-stage elaboration and gram-scale reaction. This approach achieves the divergent construction of the complex core structures that are prevalent in highly valuable natural products such as Sulpiride, Venetoclax, and Furosemide-. [ABSTRACT FROM AUTHOR]

Functionalized benzonitriles, α,β-epoxyketones and β-hydroxy-α-haloketones are found in numerous medicinally important molecules, whilst benzonitriles in combination with any of these functional groups may be of interest to medicinal chemists. However, the simultaneous incorporation of a nitrile group and these functional groups on the aromatic ring is a challenging task. Herein, we report a strategy for the rapid and simultaneous construction of structurally novel benzonitrile derivatives, possessing either an ortho -α-iodo-β-hydroxyketone, an α,β-epoxyketone or an α,β-enone, from unprotected, 2-[(3-hydroxy/acetoxy)propyn-1-yl]benzamides. This process involves NXS-promoted dehydration–halohydration followed by DIPEA-mediated epoxide formation (from alcohols). We have developed both stepwise and one-pot strategies to improve the synthetic efficiency. No metal catalyst is employed and the method exhibits good substrate scope and yields. [ABSTRACT FROM AUTHOR]

In the past few decades, transition-metal-catalyzed direct amination of aryl halides with ammonia has attracted significant attention from chemists because of its broad substrate scope, good functional group compatibility, and high reaction selectivity. Herein, recent examples of transition-metal-catalyzed syntheses of aniline derivatives starting from aryl halides are reviewed. 1 Introduction 2 Heat-Driven Transition-Metal-Catalyzed Amination of Aryl Electrophiles 2.1 Palladium-Catalyzed Amination 2.2 Copper-Catalyzed Amination 2.3 Nickel-Catalyzed Amination 3 Light-Driven Transition-Metal-Catalyzed Amination of Aryl Electrophiles 4 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

The synthesis of 1-(trifluoromethyl)alkenes through nickel-catalyzed alkylation/arylation of 1-chloro-3,3,3-trifluoroprop-1-ene (HCFO-1233zd) with alkyl/aryl zinc reagents and cobalt-catalyzed reductive cross-coupling between HCFO-1233zd and aryl bromides has been developed. These approaches feature broad substrate scope, high functional group tolerance, and the use of industrial feedstocks and low-cost nickel/cobalt catalysts, providing facile routes to access 1-(trifluoromethyl)alkenes. Diverse transformations of the resulting 1-(trifluoromethyl)alkenes demonstrated the synthetic utility of the current approaches. [ABSTRACT FROM AUTHOR]

A metal-free radical cascade cyclization of β-ketothioamides and alkyl/aryl cyanides has been developed for the synthesis of 1,2,4-thiadiazoles bearing a stable nitroso group at an exocyclic double bond in a one-pot system. The reaction proceeds via the in situ generated ketoxime intermediate of β-ketothioamide, which further assists the formation of 1,2,4-thiadiazole through reaction with nitrile under TBN (tert -butyl nitrite) mediation. The basic utility of this reaction is the formation of three new bonds (two C–N and one S–N) in one stretch under mild conditions. Moreover, this protocol features excellent functional group tolerance, operational simplicity, and easy scalability. The radical process is supported by the BHT adduct of the α-ketoxime intermediate. Noteworthy is that the products possess Z stereochemistry with regard to the exocyclic C=C double bond at the 5-position. [ABSTRACT FROM AUTHOR]

An SbCl3-initiated C sp3 –C sp3 coupling between N -aryltetrahydroisoquinolines and nitromethanes was realized through the aerobic oxidation of sp 3 C–H bond, providing a series of nitromethylated tetrahydroisoquinoline derivatives in high yields. The results exhibited that SbCl3 , as a cheap and commercially available reagent, is an efficient initiator to promote the direct functionalization of sp3 C–H bond with broad functional group tolerance, which is potentially applied to a wider range of C–H bond activation reactions. [ABSTRACT FROM AUTHOR]

An array of spiro[benzofuran-2,3′-pyrazol]-3-imines with diverse functional groups were readily assembled from aurone-derived azadienes and in - situ generated nitrilimines under mild conditions. The transformation was performed in a regio- and diastereoselective fashion, in which a synergetic [2+3] cycloaddition pathway was likely involved. This novel methodology has extended the synthetic application of aurone-derived azadienes as a kind of two-atom synthon. [ABSTRACT FROM AUTHOR]

(Hetero)aryl dehalogenation is a classical transformation usually performed using hydrogen gas and a metal supported on carbon, notably palladium (Pd/C). Though efficient, the need for a milder and operationally simple dehalogenation can arise. We found that the combination of Pd/C as catalyst and triethylsilane (TES) as hydrogen donor in THF resulted in a broadly applicable, easy to set up, and scalable debromination and deiodination. Optimization of the reaction showed that 1 mol% of Pd/C and 4 equiv of TES at room temperature were sufficient to obtain full conversion of most synthons of pharmaceutical interest in 4–24 h. The newly found conditions were applied to a large range of aromatic and heteroaromatic substrates, affording the desired targets in good to excellent yields with an exceptional functional group tolerance. [ABSTRACT FROM AUTHOR]

Using (PPh3)2 CuBH4 as catalyst, a convenient, efficient, and inexpensive palladium-free catalytic system has been developed to catalyze Sonogashira cross-coupling of o -iodoanilines with terminal alkynes under an air atmosphere to give a range of 2-ethynylaniline derivatives with up to 99% yield. This protocol is amenable to scale up. Notable features of the approach include good functional group tolerance, air atmosphere, and excellent yields. [ABSTRACT FROM AUTHOR]

Commercially available lithium triethylborohydride (LiHBEt3) with a lower load of 0.5 mol% acts as an efficient catalyst for the hydroamination of various carbodiimides. It achieved good functional group tolerance under mild and solvent-free conditions. The possible mechanism and pathways of LiHBEt3 catalyzing the hydroamination of various carbodiimides are proposed. [ABSTRACT FROM AUTHOR]

A deaminative alkyl radical cascade cyclization of 1,7-dienes is described under visible-light photocatalysis. This method delivers a family of benzoazepinones (benzazepinones) and occurs under mild reaction conditions to access a broad substrate scope with excellent functional group tolerance and good yields. This protocol has also been extended to 1,7-enynes, furnishing a representative collection of cyclopentaquinolinones. [ABSTRACT FROM AUTHOR]

A convenient, facile, and eco-friendly approach to synthesizing 7-phenyl-6 H -chromeno[4,3- b ]quinolines under microwave irradiation is presented. The current strategy enabled the synthesis of chromenoquinoline frameworks at 80 °C under shorter reaction times via intermolecular Schiff base formation followed by an intramolecular inverse demand hetero-Diels–Alder [4+2]-cycloaddition reaction by using a catalytic amount of copper triflate as the sole catalyst. Consequently, one C–N and two C–C bonds are constructed in a single pot, and a wide spread of 7-phenyl-6 H -chromeno[4,3- b ]quinolines have been synthesized with good functional group tolerance. [ABSTRACT FROM AUTHOR]

An efficient copper nitrate mediated difunctionalization of alkenes with N -fluorobenzenesulfonimide (NFSI) has been developed for the direct synthesis of β-aminonitrates in moderate to excellent yields with high regioselectivity. This reaction proceeds through a radical process, where copper nitrate is used as the nitrate source and NFSI as the nitrogen source. The given protocol provides a direct access to functionalized nitrates with operational simplicity, good functional group tolerance, and a wide substrate scope. The reaction can be performed on a gram scale and the synthetic utility of the product is demonstrated. [ABSTRACT FROM AUTHOR]

In order to develop an efficient, rapid, and modular cascade strategy for the direct synthesis of acridones, palladium supported on sulfated alumina and microwave activation are employed. Multifunctional heterogeneous palladium catalysts were prepared in order to carry out the sequential annulation via a Buchwald–Hartwig amination followed by an intramolecular annulation in a one-pot process. This new protocol represents the first report on a catalytic tandem synthesis of acridone derivatives from commercially available starting materials, under ligand-free conditions. The scope of the present methodology is extended to the generation of a library of functionalized acridones, showing high functional group compatibility, in moderate to excellent yields. The applicability of this novel transformation was demonstrated by the concise total synthesis of the natural product arborinine. [ABSTRACT FROM AUTHOR]

This work describes the high-yield synthesis of a novel series of benzotellurazoles bearing a phenyl ring in 2-position, which is differently functionalized with ethoxy chains. Changing the number and the position of these functional groups determines differences in the self-assembly in the solid state, as well as in the photophysical properties of the targeted molecules. As anticipated by theoretical calculations of the HOMO-LUMO gap of each molecule, the presence of ethoxy chains in o - and p -positions determines up to 20 nm red-shifts in the absorption peaks, when compared to unsubstituted benzotellurazole. Similarly, more significant changes are observed in the chemical shifts of125 Te NMR spectra for those derivatives bearing o - and p -ethoxy functionalization. [ABSTRACT FROM AUTHOR]

In recent times, desulfonylative radical-cross-coupling (RCC) has come to the forefront in synthetic organic, bio, and material chemistry as a powerful strategy to form C–C and C–heteroatom bonds. Diverse functionalization through metal- and photoredox-catalyzed desulfonylation reactions has attracted the scientific community due to the mild reaction conditions, wide functional group tolerance, and excellent synthetic efficacy. In this review, we have highlighted photoredox-mediated desulfonylation reactions developed since 2000. This review will summarize the newly reported methodologies, with particular emphasis on their mechanistic aspects and selectivity issues which have paved a new way towards sustainable C–C and C–X (X = H or heteroatom) bond formation. 1 Introduction 2 Photoredox-Catalyzed C–C Bond Formation 2.1 Aryl Sulfones as Radical Precursor 2.2 Reactions of Allyl Sulfones 3 Photoredox-Catalyzed C–Heteroatom Bond Formation 4 Conclusion [ABSTRACT FROM AUTHOR]

A method for radical cyclization of N -methacryloyl-2-arylbenzoimidazoles with nitriles, ketones, and tert -butyl nitrite (TBN) for the preparation of benzimidazo[2,1- a ]isoquinolin-6(5 H)-ones with the advantage of mild reaction conditions, excellent functional group compatibility, and broad substrate scope is reported. The present strategy has favorable characteristics: (1) the use of cheap metal catalysis; (2) N -radical-initiated cyclization of N -methacryloyl-2-arylbenzoimidazoles; and (3) rare example of radical C(sp3)–H functionalization in this cyclization. [ABSTRACT FROM AUTHOR]

An efficient and simple IBX-promoted oxidative ring-opening of spiro-cyclopropanyl-cyclohexadienones was developed. Disubstituted para -quinone methides were obtained with good to excellent yields and high regioselectivity (33 examples, 45–90% yields). This convenient transformation provides a new method to construct significant para -quinone methides and features high efficiency, broad substrate scope, and good functional group compatibility [ABSTRACT FROM AUTHOR]

The structural modification of phthalazinones and indazolones has emerged as a pivotal topic in catalytic C–H functionalization events. Herein we report the hydrazide-assisted rhodium(III)-catalyzed cross-coupling reactions of N -arylphthalazinones and N -arylindazolones with vinylene carbonate. This method provides direct access to tetracyclic hydroxycinnolines. Complete site-selectivity and functional group compatibility were observed. [ABSTRACT FROM AUTHOR]

A palladium/norbornene-cocatalyzed Catellani-type ortho -C–H-acylation/ ipso -cyanation of iodoarenes is developed via a three-component approach using safe and low-toxic sodium carboxylates as the acyl sources and CuCN as the CN source, affording the desired products in yields of 50–94%. Without introducing a directing group on the substrate, a catalytic amount of norbornene and palladium can regioselectively activate the ortho -C–H bonds of iodoarenes. The reaction exhibits good functional group tolerance and works well on gram-scale. In addition, this transformation allows rapid and convenient access toward isoindolinones, 1,4-dicarbonyl compounds and ortho -aminated benzonitriles by manipulation of the cyano and carbonyl groups. [ABSTRACT FROM AUTHOR]

A convenient and practical pathway to 2-cyano and 2-ester anilines is described via efficient and selective copper(II)-catalyzed reductive amination via hydrosilylation process. Both 2-cyano and 2-ester anilines were successfully synthesized with good functional group tolerance and high selectivity. The application of the 2-cyano and -iodine containing anilines was developed in the synthesis of indoloindole derivatives via CuSO4-catalyzed N -benzylation and cyclization reaction in 'one pot'. More interestingly, the photophysical property investigations of these 2-cyano and 2-ester containing anilines exhibit excellent fluorescent properties, which have great potential application in the development of interesting near-ultraviolet optical devices in the near future. [ABSTRACT FROM AUTHOR]

A novel and practical method to synthesize trifluoromethyl tertiary alcohols has been developed. Under mild reaction conditions, the present reaction could be compatible with a wide range of functional groups. Moreover, the performance of gram-scale reaction and further transformations illustrated the good potential utility of the present chemistry. Furthermore, the radical process of this reaction has been proved by mechanistic studies. [ABSTRACT FROM AUTHOR]

Direct β-arylation of thiophene derivatives with bromide as directing group is disclosed. The reaction is conducted with PdCl2 /(p -tolyl)3 P as catalyst, silver carbonate as additive, and aryl iodide as coupling partner, affording brominated biaryl compounds as product. Control experiments indicated that the presence of bromide group enhances the reactivity of the C–H bond, enabling β-arylation. Furthermore, the C–Br bond can be easily converted into many useful functional groups through a wide range of methodologies. The mechanistic study suggests that silver salt plays a key role in the C–H bond-activation step. [ABSTRACT FROM AUTHOR]

In the course of the synthesis of fused-ring analogues of the antidepressant drug tianeptine, representatives of three new heterocyclic ring systems, indolo[1,7- bc ][1,2]benzothiazepines (and their 4,5-dihydro analogues), 5,6-dihydroquino[1,8- bc ][1,2]benzothiazepines, and [1,2]benzothiazepino[4,3,2- jk ]carbazoles, as well as their intermediates, have been prepared. The tetracyclic and pentacyclic ring systems containing either an oxo or a hydroxy functional group are suitable for introducing various side chains, including potential pharmacophores. For this latter transformation, examples are demonstrated by conversion of the hydroxy group into a chloro moiety and subsequent reaction with amines or with primary alcohols bearing a tertiary amino side chain. Two fused-ring derivatives exhibiting the side-chain characteristics of tianeptine have also been synthesized. Altogether 40 compounds are described in the present manuscript, eight of them are also characterized by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The synthesis of ω-alkenylallylboronates using a heteroatom tether to join both functional groups is described for the first time. Then, these unprecedented compounds were used in a tandem Brønsted acid catalyzed allylboration/ring-closing metathesis (RCM) reaction affording heterocyclic derived alcohols as single diastereoisomers. The low enantioselectivity observed in the asymmetric version using a chiral phosphoric acid catalyst was studied theoretically. [ABSTRACT FROM AUTHOR]

A mild cascade annulation of Co(III)-catalyzed N -chlorobenz-amides with 2-acetylenic ketones at room temperature is reported. This reaction sets N–Cl bond of N -chlorobenzamide as an internal oxidant, displaying broad functional group tolerance and excellent reverse selectivity of alkyne insertion under mild and safe conditions. The cascade reaction offers a straightforward and mild protocol to construct isoquinolones in high yields at room temperature. [ABSTRACT FROM AUTHOR]

An unprecedented Cinchona alkaloid catalyzed atropoenantioselective transamination of biaryl aldehydes with 2,2-diphenylglycine via a cascade decarboxylation and dynamic kinetic resolution strategy is described. This protocol features broad substrate scope and good functional group tolerance and allows the rapid assembly of axially chiral biaryls in high yields with acceptable to good enantioselectivities. In addition, such structural motifs may have potential applications in enantioselective catalysis as chiral ligands or catalysts. [ABSTRACT FROM AUTHOR]

A blue LED-promoted dearomative oxo-spirocyclization of N -aryl- N -(2-hydroxyethyl)propiolamides is developed. The reaction works well to provide a series of selenium-containing benzo[ b ]pyrrolo[2,1- c ][1,4]oxazine-3,9-diones with high efficiency and good tolerance for functional groups. Besides, diselenium-containing benzo[ b ]pyrrolo[2,1- c ][1,4]oxazine-3,9-diones can also be efficiently synthesized in the presence of Oxone. In this process, it is believed that a selenium radical-triggered ipso -cyclization and oxo-Michael addition are involved. Further applications using the prepared products in bioactivity assay is currently underway. [ABSTRACT FROM AUTHOR]

A direct dehydroxylative and decarboxylative coupling between a large number of allylic alcohols and alkynoic acids was realized affording 1,4-enyne motifs in high efficiency. In this reaction, calcium-promoted C–OH bond cleavage was crucial, which facilitated the sequential -decarboxylation, and thus enabled the palladium-catalyzed allyl-–alkynyl coupling, which occurred in an environmentally benign manner tolerating a wide variety of functional groups. This protocol has been successfully used in preparing anticancer active rooperol derivatives in gram scale. [ABSTRACT FROM AUTHOR]

Cyclopropyldiphenylsulfonium salt, a famous ylide precursor previously extensively employed in the preparation of cyclic compounds, has been successfully utilized as an efficient allylation reagent in this work. The copper-catalyzed reactions of cyclopropyldiphenylsulfonium trifluoromethanesulfonate with amines in the presence of an appropriate ligand provided the N -allylated products in good yields. Aliphatic/aromatic amines and primary/secondary amines were all converted under mild reaction conditions. This protocol was also applicable to N -functionalization of drug molecules, supplying the corresponding N -allylated compounds in satisfactory yields. The reaction, which showed good functional group tolerance with a wide range of substrates and excellent chemoselectivity, offers an interesting method for the synthesis of N -allyl amines. [ABSTRACT FROM AUTHOR]

A novel reaction of propargylamines with aryl azides is designed for the synthesis of 5-amino-1,2,3-triazoles employing a one-pot strategy. In this process, base-mediated isomerization of propargylamines generates allenamine intermediates, which participate in a cyclization reaction with azides. Optimization of the reaction conditions revealed that t -BuOK as the base and DMF as the solvent gave the best yields. This protocol is expanded to different propargylamines and azides, with the results showing that 3-aryl propargylamines and aryl azides are tolerated to produce the corresponding 1,2,3-triazoles. This procedure provides a simple and efficient method to access a series of 5-amino-1,2,3-triazoles possessing a wide spectrum of functional groups. [ABSTRACT FROM AUTHOR]

A nickel-catalyzed cross-electrophile coupling is disclosed in which a range of vinyl bromides were utilized as electrophiles with oxalates derived from α-hydroxy carbonyls as precursors to carbonyl radical coupling partners. This method is compatible with a broad range of functional groups, providing a complementary solution for the construction of β,γ-unsaturated carbonyl compounds. [ABSTRACT FROM AUTHOR]

A convenient procedure for the chemoselective reduction of tertiary amides at room temperature in the presence of air and moisture using 1,3-diphenyldisiloxane (DPDS) is developed. The reaction conditions tolerate a significant number of functional groups including esters, nitriles, secondary amides, carbamates, sulfoxides, sulfones, sulfonyl fluorides, halogens, aryl-nitro groups, and arylamines. The conditions reported are the mildest to date and utilize EtOAc, a preferred solvent given its excellent safety profile and lower environmental impact. The ease of setup and broad chemoselectivity make this method attractive for organic synthesis, and the results further demonstrate the utility of DPDS as a selective reducing agent. [ABSTRACT FROM AUTHOR]

The application of alkylsulfonium salts as alkyl-transfer reagents in organic synthesis has reemerged over the past few years. Numerous heteroatom- and carbon-centered nucleophiles, alkenes, arenes, alkynes, organometallic reagents, and others are readily alkylated by alkylsulfonium salts under mild conditions. The reactions feature convenience, high efficiency, readily accessible and structurally diversified alkylation reagents, good functional group tolerance, and a wide range of substrate types, allowing the facile synthesis of various useful organic molecules from commercially available building blocks. This review summarizes alkylation reactions using either isolated or in situ formed alkylsulfonium salts via nucleophilic substitution, transition-metal-catalyzed reactions, and photoredox processes. 1 Introduction 2 General Methods for the Synthesis of Alkylsulfonium Salts 3 Electrophilic Alkylation Using Alkylsulfonium Salts 4 Transition-Metal-Catalyzed Alkylation Using Alkylsulfonium Salts 5 Photoredox-Catalyzed Alkylation Using Alkylsulfonium Salts 6 Conclusion [ABSTRACT FROM AUTHOR]

The development of chiral borane Lewis acid catalysts opened the door for transition-metal-free catalyzed asymmetric organic reactions. Herein, we have summarized our work on the preparation of two classes of novel chiral bicyclic bisborane Lewis acid catalysts derived from C 2-symmetric [3.3.0] dienes and [4.4] dienes, respectively. These catalysts not only form frustrated Lewis pairs with Lewis bases to catalyze asymmetric hydrogenation reactions but also activate Lewis basic functional groups in traditional Lewis acid catalyzed asymmetric reactions. 1 Introduction 2 Synthesis of C 2-Symmetric Fused Bicyclic Bisborane Catalysts and Their Use in Imine Hydrogenation 3 Synthesis of Spiro Bicyclic Bisborane Catalysts and Their Use in -N -Heteroarene Reduction 4 Other Types of Asymmetric Reactions Promoted by Chiral -Bicyclic Bisborane Catalysts 5 Conclusion [ABSTRACT FROM AUTHOR]

An efficient and versatile copper-catalyzed intermolecular radical [3+2] annulation of thioamides with azobisisobutyronitrile (AIBN) is described. This two-component copper(II)-catalyzed transformation is achieved in one pot via cascade formation of C–S/C–N bonds through cyclization of an in situ generated N , S -acetal intermediate derived from a β-ketothioamide. This operationally simple method allows direct access to synthetically demanding thiazolidin-4-ones in good to excellent yields containing diverse functional groups of different electronic and steric nature. The readily available reaction partners, the avoidance of expensive/toxic reagents and a gram-scale synthesis are additional attributes of this strategy. AIBN plays a dual role as a radical initiator and an unusual source of a two-carbon coupling partner. Notably, the products possess Z stereochemistry with regard to the exo-cyclic C=C double bond at position 2 of the thiazolidine ring. [ABSTRACT FROM AUTHOR]

A new type of ligand-free Ni-nanoparticles supported on rGO (size distribution average d = 9 ± 3 nm) was prepared and fully characterized via morphological (Fe-SEM), structural (P-XRD, HR-TEM), and spectroscopic (ICP-EOS, XPS) analysis tools. The metal composite was effectively employed in the unprecedented heterogeneously Ni-assisted cross-coupling reaction of aryl/vinyl iodides and thiocarboxylates. A range of sulfur-containing aryl as well as vinyl derivatives (15 examples) was achieved in high yields (up to 82%), under mild reaction conditions, and with wide functional group tolerance. [ABSTRACT FROM AUTHOR]

The reaction of N -arylpropynamides with (dichloroiodo)benzene (PhICl2) and diselenides/disulfides resulted in a divergent synthesis of chalcogenylated quinolinones and spiro[4.5]trienes through intramolecular electrophilic cyclization and chalcogenylation. The chalcogenyl functional group was introduced by an electrophilic reactive organosulfenyl chloride or selenenyl chloride species, generated in situ from the reaction of disulfides/diselenides and PhICl2. Notably, the divergent cyclization pathways were determined by the substituent type on the aniline ring in N -arylpropynamide substrates. Substrates bearing a fluoro, methoxy or trifluoromethoxy group at the para -position of the aniline underwent an alternative spiralization pathway to give the 3-chalcogenylated spiro[4,5]trienones. [ABSTRACT FROM AUTHOR]

Pd2 dba3 /XPhos in poly(ethylene glycol) (PEG-2000) is shown to be a highly stable and efficient catalyst for the borylation of aryl chlorides with bis(pinacolato)diboron. The borylation reaction proceeds smoothly at 110 °C, delivering a wide variety of aryl boronates in good to excellent yields with high functional group tolerance. The crude products were easily isolated via simple extraction of the reaction mixture with cyclohexane. Moreover, both expensive Pd2 dba3 and XPhos in PEG-2000 system could be readily recycled and reused more than six times without loss of catalytic efficiency. [ABSTRACT FROM AUTHOR]

The reaction of N -arylpropynamides with (dichloroiodo)benzene (PhICl2) and diselenides/disulfides resulted in a divergent synthesis of chalcogenylated quinolinones and spiro[4.5]trienes through intramolecular electrophilic cyclization and chalcogenylation. The chalcogenyl functional group was introduced by an electrophilic reactive organosulfenyl chloride or selenenyl chloride species, generated in situ from the reaction of disulfides/diselenides and PhICl2. Notably, the divergent cyclization pathways were determined by the substituent type on the aniline ring in N -arylpropynamide substrates. Substrates bearing a fluoro, methoxy or trifluoromethoxy group at the para -position of the aniline underwent an alternative spiralization pathway to give the 3-chalcogenylated spiro[4,5]trienones. [ABSTRACT FROM AUTHOR]

An SN 2′ defluorinative allylation of trifluoromethylalkenes with readily available allylsilanes to access homoallyl gem -difluoroalkenes is reported. The reaction is triggered by a catalytic amount of TBAF, with the extruded fluoride in the reaction serving as a sustainable activator for organosilanes. The high efficiency, good functional group tolerance, and mild reaction conditions underline the potential of this method in synthetic chemistry. [ABSTRACT FROM AUTHOR]

A highly efficient method for the synthesis of S -aryl dithiocarbamates is reported. By using tetramethylthiuram monosulfide (TMTM) and aryl boronic acids as starting materials, C(sp2)–S bond-forming reactions proceed smoothly to give the desired aryl dithiocarbamates in good to excellent yields. The methodology features a simple procedure, broad functional group tolerance and excellent yields, whilst showing potential synthetic value for the preparation of a diverse range of biologically and pharmaceutically active compounds. [ABSTRACT FROM AUTHOR]

A convenient approach to assemble 1,2,3-triazole-fused 4 H -3,1-benzoxazines has been developed. Diverse alcohol-tethered 5-iodotriazoles, readily accessible by a modified protocol of Cu-catalyzed (3+2)-cycloaddition, were utilized as precursors of the target fused heterocycles. The intramolecular C–O coupling proceeded efficiently under base-mediated transition-metal-free conditions, furnishing cyclization products in yields up to 96%. Suppression of the competing reductive cleavage of the C–I bond was achieved by the use of Na2 CO3 in acetonitrile at 100 °C. This practical and cost-effective procedure features a broad substrate scope and valuable functional group tolerance. [ABSTRACT FROM AUTHOR]

Herein, we present a palladium-catalyzed tandem [4+1] cyclo-addition of 4-vinyl-1,4-dihydro-2 H -3,1-benzoxazin-2-ones with -N -tosyl-hydrazones. The reaction is accomplished by merging the in situ generated aza- ortho -quinone methides (aza- o -QMs) with nucleophilic carbenes. This method enables the construction of diverse indolines with broad functional group compatibility in good yields with high levels of diastereoselectivity under mild conditions. [ABSTRACT FROM AUTHOR]

An efficient, one-pot, domino synthesis of quinolines via the coupling of iodoanilines with allylic alcohols facilitated by palladium catalysis is described. The overall synthetic process involves an intermolecular Heck coupling between 2-iodoanilines and allylic alcohols, intramolecular condensation of in situ generated ketones with an internal amine functional group, and a dehydrogenation sequence. Notably, this protocol occurs in water as a green solvent. Significantly, the method exhibits broad substrate scope and is applied for the synthesis of deuterated quinolines through a deuterium-exchange process. [ABSTRACT FROM AUTHOR]

Pyrazolo[3,4- b ]pyridine is a privileged scaffold found in many small drug molecules that possess a wide range of pharmacological properties. Efforts to further develop and exploit synthetic methodologies that permit the functionalization of this heterocyclic moiety warrant investigation. To this end, a series of novel 1,3-disubstituted pyrazolo[3,4- b ]pyridine-3-carboxamide derivatives have been prepared by introducing the 3-carboxamide moiety using palladium-catalyzed aminocarbonylation methodology and employing CO gas generated ex situ using a two-chamber reactor (COware®). The functional group tolerance of this optimized aminocarbonylation protocol is highlighted through the synthesis of a range of diversely substituted C-3 carbox-amide pyrazolo[3,4- b ]pyridines in excellent yields of up to 99%. [ABSTRACT FROM AUTHOR]

The metal-free oxidative alkene methylation/alkynylation of 1,4-enyn-3-ols with an organic peroxide as the methyl source has been developed, which provides straightforward and practical access to the challenging quaternary-carbon-containing but-3-yn-1-ones. The method is reasoned to go through methylation of functional alkenes utilizing dicumyl peroxide as the methylating reagent and subsequent intermolecular cyclization/1,2-alkynyl migration. This reaction has an excellent functional group tolerance, broad substrate scope, and exquisite selectivity. [ABSTRACT FROM AUTHOR]