Abstract Platinum‐catalyzed formal [5+2] and [4+2] annulations of isoxazoles with heterosubstituted alkynes enabled the atom‐economical synthesis valuable 1,3‐oxazepines 2,5‐dihydropyridines, respectively. Importantly, this Pt catalysis not only led to unique reactivity dramatically divergent from that observed under Au catalysis, but also proceeded via unprecedented α‐imino platinum carbene intermediates.

Abstract Gold-catalyzed intermolecular alkyne oxidation by an N–O bond oxidant has proven to be a powerful method in organic synthesis during the past decade, because this approach would enable readily available alkynes as precursors generating α-oxo gold carbenes. Among those, gold-catalyzed oxidative cyclization of dialkynes received particular attention chemistry offers great potential build structurally complex cyclic molecules. However, these oxidations have been mostly limited noble...

A novel near-infrared (NIR) fluorescent Probe 1 was successfully developed for the reversible detection of sulfur dioxide derivatives and formaldehyde. The purple solution faded to colorless in 1.8 s with addition HSO3-. Meanwhile, its fluorescence signal disappeared instantaneously a 39 nM limit. probe exhibited excellent selectivity toward HSO3- over other potential interfering agents. Then, absorption bands were able effectively recover response Remarkably, this reverse process accelerate...

Recent rapid development in homogeneous gold catalysis affords an alternative and particularly thriving strategy for the generation of carbenes through gold-catalyzed oxidation/amination/cycloaddition alkynes, while it avoids employment hazardous potentially explosive diazo compounds as starting materials carbene generation. In addition to facile secure operation, generated this display good chemoselectivity distinct from other metal produced related approach. N-heterocyclic (NHC) is a...

The difunctionalization of electron-enriched styrenes for the synthesis substituted tetrahydrofurans and tetrahydropyrans in presence photoredox catalysts is described. procedure highlighted by its operational simplicity, low catalyst loadings (1 mol%), excellent stereoselectivity mild reaction conditions.

Abstract Platinum‐catalyzed formal [5+2] and [4+2] annulations of isoxazoles with heterosubstituted alkynes enabled the atom‐economical synthesis valuable 1,3‐oxazepines 2,5‐dihydropyridines, respectively. Importantly, this Pt catalysis not only led to unique reactivity dramatically divergent from that observed under Au catalysis, but also proceeded via unprecedented α‐imino platinum carbene intermediates.

Comprehensive Summary A new class of near‐infrared (NIR) fluorescent organoboron AIEgens was successfully developed for latent fingerprints (LFPs) imaging. They exhibit real‐time and in situ high‐resolution imaging performance at 1—3 levels LFPs by spraying method. In addition, we systematically elucidate the fingerprint mechanism these AIEgens. Significantly, excellent level 3 structural capabilities enable application them analyzing incomplete identifying individuals different scenarios.

A new gold-catalyzed cascade cyclization of <italic>N</italic>-propargyl ynamides involving a presumable vinyl cation intermediate has been developed, allowing the efficient and practical synthesis various functionalized indeno[1,2-<italic>c</italic>]pyrroles.

A novel zinc-catalyzed reaction of isoxazoles with thioynol ethers involving an unprecedented 1,2-sulfur migration has been developed.

An efficient copper(I)-catalyzed enyne oxidation/cyclopropanation for the modular synthesis of cyclopropane derivatives is described, which represents first non-noble metal-catalyzed enynes by in situ generated α-oxo copper carbenes. This protocol allows assembly valuable cyclopropane-γ-lactams generally good to excellent yields with diastereoselectivity. More significantly, enantioselective version has been disclosed chiral catalysts.

Homogeneous transition‐metal‐catalyzed alkyne cascade cyclization reaction has attracted much attentions over the past decades. However, relevant homogeneous of allenynes seldom been explored probably due to noticeable chemo‐, regio‐, and stereoselectivity. Described herein is an efficient copper‐catalyzed cycloisomerization allenynes, thus leading a practical atom‐economic access array valuable functionalized pyrroles by formal [3 + 2] cycloaddition via Cu‐containing all‐carbon 1,4‐dipoles.

In recent years, gold-metal-catalyzed intermolecular alkyne oxidation by an <italic>N</italic>-oxide oxidant, which presumably involves a gold carbenoid intermediate, has attracted increasing attention because it circumvents the employment of hazardous and potentially explosive diazocarbonyl compounds as starting materials for carbene generation.

This review is to highlight the recent progresses in transition-metal-catalyzed Nazarov cyclization of alkynes <italic>via</italic> metal carbenes, such as α-oxo carbene, α-imino α-phenyl carbene and α-cyclopropyl carbene.

Described herein is a copper-catalyzed multifunctionalization of indolyl ynones, allowing the synthesis dihalogen-substituted spiroindoles. This Cu catalysis also applicable to cyclopenta[ c ]quinolin-3-ones via decarbonylation.

An efficient Cu(I)-catalyzed oxidative cyclization of alkynyl-tethered enynamides for the construction fused bicyclic cyclopentadiene derivatives is disclosed. The cascade proceeds through alkyne oxidation, carbene/alkyne metathesis, and formal (3 + 2) cycloaddition. Employing aryl-tethered as starting materials, substituted 2-aminofurans can be exclusively formed.

Abstract General access to highly valuable seven-membered rings via Büchner-type reaction remains a formidable challenge. Here we report Cu-catalyzed intermolecular oxidation of alkynes using N-oxides as oxidants, which enables expedient preparation benzo[6,7]azepino[2,3-b]quinolines and pyridine-based diones. Importantly, in contrast the well-established gold-catalyzed alkyne oxidation, dissociated pyridine or quinoline partner could be further utilized construct N-heterocycles this system...

The efficient and divergent construction of two types valuable N-heterocycle is achieved easily, with the first example generation α-oxo copper carbenes via copper-catalyzed oxidation non-polarized alkynes.

A highly convenient copper(I)-catalyzed oxidation-initiated cyclopropanation of indolyl ynamide for the rapid construction indole-fused cyclopropane-lactams is described, which represents, to best our knowledge, first non-noble-metal-catalyzed oxidation/dearomatization by in situ generated α-oxo copper carbenes. Compared hydrazone and diazo, use alkynes as carbene precursors allows occur under a safe pathway. Moreover, this transformation can lead divergent synthesis pentacyclic...

Polycyclic N-heterocycles are important structural motifs commonly found in bioactive compounds, however, their selective construction via the cyclization of allenynes remains challenging yet highly desirable. Here we show a homogeneous copper-catalyzed hetero Diels-Alder (HDA) reaction with cis-diazenes (PTAD, 4-phenyl-1,2,4-triazoline-3,5-dione), allowing practical and efficient synthesis diverse array valuable polycyclic N-heterocycles. A temperature-controlled stereocontrolled...

An efficient gold-catalyzed oxidative cyclization of amide-alkynes is developed. A series functionalized γ-lactams are easily accessed by employing this strategy. The tandem reaction proceeds through alkyne oxidation, carbene/alkyne metathesis, and donor/donor carbene oxidation.

Described herein is an efficient copper-catalyzed tandem alkyne indolylcupration-initiated 1,2-indole migration/6π-electrocyclic reaction of allene-ynamides with indoles by the in situ-generated metal carbenes. This method allows synthesis valuable indole-fused spirobenzo[f]indole-cyclohexanes high regio- and stereoselectivity. In addition, this affords rapid access to functionalized absence a presumable 5-exo-dig cyclization/Friedel–Crafts alkylation via copper-containing all-carbon 1,4-dipoles.

Abstract Dearomatizing spirocyclization reactions are very appealing synthetic strategies to generate functionalized three-dimensional scaffolds from simple two-dimensional precursors. Recently, the field of transition-metal-catalyzed dearomatizing indolyl ynones has burgeoned, as construction synthetically challenging quaternary spirocyclic carbons is easily achieved. In this review, we introduce an overview advances in ynones, with being categorized according type catalyst.

Abstract An efficient copper-catalyzed oxidative cyclization of diynes is described. A range functionalized γ-lactams can be readily constructed by using this protocol. This process proceeds through an alkyne oxidation, carbene/alkyne metathesis, and donor–donor carbene oxidation sequence. The use available substrates, high flexibility, a simple procedure, mild reaction conditions render the procedure viable alternative for preparation γ-lactams.