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Over the past two decades, the development and application of ynamide chemistry have received more and more attention. Ynamides have proven to be versatile reagents for organic synthesis, and have been widely applied to the rapid assembly of a diverse range of structurally complex N-containing molecules, especially the valuable N-heterocycles. In comparison with the well-established transition metal-catalyzed reactions of ynamides, metal-free ynamide transformations have relatively seldom been exploited. Recently, Brønsted acid-mediated reactions of ynamides represent significant advances in ynamide chemistry. This review summarizes the latest trends and developments of Brønsted acid-mediated reactions of ynamides, including cycloaddition, cyclization, intramolecular alkoxylation-initiated rearrangement, oxygen atom transfer reactions and hydro-heteroatom addition reactions. [ABSTRACT FROM AUTHOR]

C31H42Br2N4Pd, monoclinic, P21/ c, a = 12.3093(14)Å, b = 15.2805(18) Å, c = 20.3205(17) Å, β = 112.213(5)°, V = 3538.5(7) Å3, Z = 4, Rgt( F) = 0.0540, wRref( F2) = 0.1528, T = 298(2)K. [ABSTRACT FROM AUTHOR]

A silver-mediated cascade trifluoromethylthiolation and cyclization has been developed for the synthesis of 2-(trifluoromethylthio)-indenones. A variety of arylpropynones underwent this radical oxidative cyclization with AgSCF 3 to afford trifluoromethylthiolated indenones in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

A new, metal-free method for the formation of C(sp3)-O bonds was established by PhI(OAc)2-mediated oxygenation of benzylic C(sp3)-H bonds with N-hydroxyamides at room temperature, in which the C(sp3)-H oxidation is activated by a polyflurophenylamide group. [ABSTRACT FROM AUTHOR]

• Rh-catalyzed annulation of 2-aryl quinazolin-4(3 H)-ones and sulfoxonium ylides. • Sequential ortho- C H functionalization/unprecedented carbonyl α-amination. • Application in facile accessing 13-aroyl luotonin A derivatives. A rhodium-catalyzed [4+1] annulation between 2-aryl quinazolin-4(3 H)-ones and sulfoxonium ylides was developed, leading to 12-aroyl isoindolo[1,2- b ]quinazolin-10(12 H)-ones in moderate to good yields. This reaction proceeds with sequential ortho- C H functionalization of 2-aryl quinazolin-4(3 H)-ones and an intramolecular rhodium-catalyzed α-amination of carbonyl to furnish the cyclization. This procedure was applied to access some 13-aroyl luotonin A derivatives whereby the direct construction of ring c. [ABSTRACT FROM AUTHOR]

Ynamides are electron‐rich heteroatom‐substituted alkynes with C−C triple bond directly tethered to the amide group. Over the past decades, ynamides have proven to be versatile reagents for organic synthesis and have received extensive attention. Compared with the well‐established ionic reactions of ynamides, radical‐based ynamide reactions have been exploited relatively seldom. Herein, radical reactions of ynamides, classified by radical attack at the α‐position and β‐position of ynamides, are reviewed by highlighting the reaction selectivity, scope, mechanism, and applicability. The aim of this review is to provide a comprehensive summarization of these advances, casting light on the further development of ynamide chemistry. [ABSTRACT FROM AUTHOR]

C17H23Cl2N3Pd, orthorhombic, P212121 (no. 19), a = 9.6460(18) Å, b = 13.883(3) Å, c = 14.520(3) Å, V = 1944.4(6) Å3, Z = 4, Rgt (F) = 0.0373, wRref (F2 ) = 0.0917, T = 298(2) K. [ABSTRACT FROM AUTHOR]

The enantioselective transformation of easily accessible 1,2-diketones represents a quick pathway towards enantioenriched molecules. Herein, we disclose a copper-catalyzed atroposelective formal [4+1] annulation of 1,2-diketones with vinyl cations, enabling the efficient and atom-economical construction of axially chiral arylpyrroles bearing 1,3-dioxole moieties with good to excellent enantioselectivities under mild reaction conditions. Importantly, this methodology constitutes the first enantioselective formal [4+1] annulation of 1,2-diketones. [ABSTRACT FROM AUTHOR]

One-carbon homologation reactions based on one-carbon insertion into the N−O bond of heterocycles have received tremendous interest over the past decades. However, these protocols have to rely on the use of hazardous and not easily accessible diazo compounds as precursors, and examples of the relevant asymmetric catalysis have not been reported. Here we show that a copper-catalyzed intermolecular formal (5 + 1) annulation of 1,5-diynes with 1,2,5-oxadiazoles involving one-carbon insertion into the heterocyclic N−O bond via non-diazo approach. This method enables practical and atom-economic synthesis of valuable pyrrole-substituted oxadiazines in generally moderate to good yields under mild reaction conditions. In addition, the possibility of such an asymmetric formal (5 + 1) annulation also emerges. One-carbon insertion into N–O bonds is widely exploited in organic synthesis, but synthetic protocols for this rely on hazardous diazo precursors that are difficult to access. Here, copper-catalyzed intermolecular formal (5 + 1) annulation of 1,5-diynes with 1,2,5-oxadiazoles is shown to facilitate one-carbon insertion into heterocyclic N–O bonds without the need for diazo precursors. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Synthesis of Malonates from 3-Halopropynoates, Alcohols, and Water Using DABCO" by Peng-Cheng Qian published in the "Synthesis" in 2015.

A facile, copper-catalyzed sequential oxidative C-S bond formation, ipso-cyclization, and dearomatization strategy assembles the title compounds (III),(V),(VII),(IX),(XI) using an inexpensive catalytic system and molecular oxygen as oxidant. [ABSTRACT FROM AUTHOR]

A new and general, catalyst-free strategy for the formation of C(sp3)-O bonds is established by iodosobenzene diacetate-mediated oxygenation of benzylic C(sp3)-H bonds with N-hydroxyamides. [ABSTRACT FROM AUTHOR]

Herein, an I2‐catalyzed unprecedented cycloisomerization of ynamides is developed, furnishing various functionalized bis(indole) derivatives in generally good to excellent yields with wide substrate scope and excellent atom‐economy. This protocol not only represents the first molecular‐iodine‐catalyzed tandem complex alkyne cycloisomerizations, but also constitutes the first chemoselective cycloisomerization of tryptamine‐ynamides involving distinctively different C(sp3)−C(sp3) bond cleavage and rearrangement. Moreover, chiral tetrahydropyridine frameworks containing two stereocenters are obtained with moderate to excellent diastereoselectivities and excellent enantioselectivities. Meanwhile, cycloisomerization and aromatization of ynamides produce pyrrolyl indoles with high efficiency enabled by I2. Additionally, control experiments and theoretical calculations reveal that this reaction probably undergoes a tandem 5‐exo‐dig cyclization/rearrangement process. [ABSTRACT FROM AUTHOR]

Herein, an I2‐catalyzed unprecedented cycloisomerization of ynamides is developed, furnishing various functionalized bis(indole) derivatives in generally good to excellent yields with wide substrate scope and excellent atom‐economy. This protocol not only represents the first molecular‐iodine‐catalyzed tandem complex alkyne cycloisomerizations, but also constitutes the first chemoselective cycloisomerization of tryptamine‐ynamides involving distinctively different C(sp3)−C(sp3) bond cleavage and rearrangement. Moreover, chiral tetrahydropyridine frameworks containing two stereocenters are obtained with moderate to excellent diastereoselectivities and excellent enantioselectivities. Meanwhile, cycloisomerization and aromatization of ynamides produce pyrrolyl indoles with high efficiency enabled by I2. Additionally, control experiments and theoretical calculations reveal that this reaction probably undergoes a tandem 5‐exo‐dig cyclization/rearrangement process. [ABSTRACT FROM AUTHOR]

We have developed a copper-mediated chelation-assisted direct aromatic ortho -C–H cyanation that uses AIBN as a safe cyanation reagent. The substrate scope included indoles, pyrroles, a carbazole, and a thiophene. [ABSTRACT FROM AUTHOR]

An Ir‐catalyzed remote dearomatizative amidation for the enantioselective construction of chiral spirolactams in 70–93% yield with 81–96% ee was developed. This protocol represented a more atom‐economical approach to chiral spirolactams via Ir‐catalyzed nitrenoid transfer without the introduction of a traceless O‐silyl achiral auxiliary. [ABSTRACT FROM AUTHOR]

[Display omitted] A silver-mediated annulation between arylcarbamic acids and nitrosoarenes was developed, leading to phenazines in moderate to good yields with complexity and diversity. This procedure proceeded with the sequential ortho C H functionalization of arylcarbamic acids, insertion to nitroso group and decarboxylative annulation. [ABSTRACT FROM AUTHOR]

An efficient regio- and diastereoselective method for the construction of valuable trans-3,4-diaryldihydrocoumarins via metal-free [4+2] annulation of ynamides with o-hydroxybenzyl alcohols has been developed. Ynamides are first treated as 2–π partners to react with o-hydroxybenzyl alcohols via traceless sulfonamide directing groups, affording trans-3,4-diaryldihydrocoumarins in good yields with high regio- and diastereoselectivities. This metal-free methodology is also characterized by a wide substrate scope, good functional group tolerance, and efficiency on a gram scale. [ABSTRACT FROM AUTHOR]

In this paper, we developed a rhodium-catalyzed annulation of vinylene carbonate with amidines, leading to 4-methylquinazolines with moderate to excellent yields. This procedure proceeded by sequential ortho-acylation and annulation, where vinylene carbonate served as the acetylation reagent rather than the ethyne surrogate. [ABSTRACT FROM AUTHOR]

A metal‐complex‐modified graphitic carbon nitride (g‐C3N4) bulk heterostructure is presented here as a promising alternative to high‐cost noble metals as artificial photocatalysts. Theoretical and experimental studies of the spectral and physicochemical properties of three structurally similar molecules Fo–D, Pt–D, and Pt–P confirm that the Pt(II) acetylide group effectively expands the electron delocalization and adjusts the molecular orbital levels to form a relatively narrow bandgap. Using these molecules, the donor–acceptor assemblies Fo–D@CN, Pt–D@CN, and Pt–P@CN are formed with g‐C3N4. Among these assemblies, the Pt(II) acetylide‐based composite materials Pt–D@CN and Pt–P@CN with bulk heterojunction morphologies and extremely low Pt weight ratios of 0.19% and 0.24%, respectively, exhibit the fastest charge transfer and best light‐harvesting efficiencies. Among the tested assemblies, 10 mg Pt–P@CN without any Pt metal additives exhibits a significantly improved photocatalytic H2 generation rate of 1.38 µmol h−1 under simulated sunlight irradiation (AM1.5G, filter), which is sixfold higher than that of the pristine g‐C3N4. [ABSTRACT FROM AUTHOR]

In the presence of TsNHNH2, a Brønsted acid-promoted intramolecular cyclization of o-(1-arylvinyl) acetophenone derivatives was developed, leading to polysubstituted indenes with complexity and diversity in moderate to excellent yields. In sharp contrast with either the radical or carbene involved cyclization of aldehydic N-tosylhydrazone with vinyl, a cationic cyclization pathway was involved, where N-tosylhydrazone served as an electrophile and alkylation reagent during this transformation. [ABSTRACT FROM AUTHOR]

Two soft salts (S1 and S2) based on platinum(II) complexes with a near-infrared emission have been designed and synthesized. It has been demonstrated that S2 has a high photostability and a low cytotoxicity, and it has been successfully applied to in vivo imaging for the first time. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: An efficient copper‐catalyzed carbocyclization of silyl enol ether tethered ynamides has been developed, allowing rapid and practical construction of diverse 2‐azabicyclo[3.2.0] compounds in generally good to excellent yields with broad substrate scope under mild reaction conditions. Importantly, this protocol not only constitutes a rare example of non‐noble metal‐catalyzed alkyne carbocyclization, but also represents a rare cyclization on the β‐position of π‐tethered ynamides. The possibility of asymmetric carbocyclization via kinetic resolution also emerges. [ABSTRACT FROM AUTHOR]

An efficient copper-catalyzed tandem regioselective cis-carbometallation/cyclization of imine-ynamides with arylboronic acids has been developed. This method leads to a facile and practical synthesis of valuable 2,3-disubstituted indolines in moderate to excellent yields and features a broad substrate scope and wide functional group tolerance. Other significant features of this protocol include the use of readily available starting materials, high flexibility, simple procedure and mild reaction conditions. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: An efficient zinc‐catalyzed oxidative cyclization of readily available indoly ynamides has been developed, enabling rapid and practical access to a diverse array of valuable medium‐sized lactams in mostly good to excellent yields with wide substrate scope. In addition, such an asymmetric synthesis has also been explored by employing the chiral substrate. [ABSTRACT FROM AUTHOR]

NHC-Pd(II)-Im complex showed efficient catalytic activity toward the direct C H bond arylation of (benzo)thiophenes with the challenging aryl chlorides. Under the suitable conditions, all reactions proceeded smoothly to give the desired C H bond arylated products in acceptable to high yields, giving an inexpensive and alternative methodology for the arylation of (benzo)thiophenes. [ABSTRACT FROM AUTHOR]

Here we describe the one-pot construction of the pyrrolo[4,3,2-de]quinolinone scaffold by a cascade nitration/cyclization sequence of 1,7-enynes with tBuONO and H2O. The cascade proceeds through alkene nitration, 1,7-enyne 6- exo-trig cyclization, CH nitrations, and redox cyclization, and exhibits excellent functional group tolerance. The mechanism was investigated using in situ high-resolution mass spectrometry (HR-MS). [ABSTRACT FROM AUTHOR]

Here we describe the one-pot construction of the pyrrolo[4,3,2-de]quinolinone scaffold by a cascade nitration/cyclization sequence of 1,7-enynes with tBuONO and H2O. The cascade proceeds through alkene nitration, 1,7-enyne 6- exo-trig cyclization, CH nitrations, and redox cyclization, and exhibits excellent functional group tolerance. The mechanism was investigated using in situ high-resolution mass spectrometry (HR-MS). [ABSTRACT FROM AUTHOR]

Synthese unter Blaulicht: 10a,11 ‐ Dihydro ‐ 10H ‐ benzo[b]fluorene sind durch die katalytische Titelreaktion unter Bestrahlung mit sichtbarem Licht zugänglich. Die Methode stellt eine neue Anwendung von Arylsulfonylchloriden in der Synthese dar und erweitert das Spektrum von Enincyclisierungen. [ABSTRACT FROM AUTHOR]

Ray of light: 10a,11‐Dihydro‐10H‐benzo[b]fluorenes were synthesized by a visible‐light‐catalyzed tandem cyclization of 1,6‐enynes with arylsulfonyl chlorides. This method extends the scope of enyne cyclizations and represents a new synthetic application of arylsulfonyl chlorides. [ABSTRACT FROM AUTHOR]

[Display omitted] In this paper, we reported a copper-catalyzed ring-opening reaction of arylcyclopropanes by N -fluorobenzenesulfonimide, leading to N -allylsulfonamides in moderate to good yields. This procedure tolerated bromo, fluoro, trifluoromethyl, phenyl and alkyl groups in the phenyl, proceeding with a sequential ring-opening of arylcyclopropanes, and copper-mediated β-H elimination of alkyl radical. [ABSTRACT FROM AUTHOR]

[Display omitted] • Conjugated polyelectrolyte was developed and used as a dopant in PSCs. • PPNNA doping improves the formation of the perovskite film. • PPNNA doping realizes efficient surface passivation and electron extraction. • PPNNA can significantly enhance device performance and stability. Perovskite solar cells (PSCs) have achieved great success in the past few years because of outstanding photovoltaic performance. However, the existence of electronic trap states in the perovskite film is an obstacle for the fabrication of high-performance and stable PSCs. Herein, a linear conjugated polyelectrolyte was developed and employed as a dopant to improve the performance and stability of the perovskite film. The PPNNA doping can passivate surface defects to reduce the electronic trap states in the perovskite film, while simultaneously enhancing the electron extraction and transport to achieve high-efficiency solar cells. Furthermore, the PPNNA-doped perovskite film shows better stability from efficient surface passivation. The optimal 0.4% PPNNA-doped device exhibits better photovoltaic efficiency (20.38%) with enhanced device stability as compared to the control device (18.51%). This novel method by doping with the conjugated polyelectrolyte provides a pathway to fabricate high-efficiency and stable inverted PSCs. [ABSTRACT FROM AUTHOR]

An abstract of the article "Cascade Nitration/Cyclization of 1,7-Enynes with tBuONO and H2O: One-Pot Self-Assembly of Pyrrolo[4,3,2-de]quinolinones" is presented.