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We report chemo- and regioselective direct reductive deoxygenation of 1-en-4-yn-3-ols into 1,4-enynes through FeF3 and TfOH cooperative catalysis under NBSH-mediated conditions. Further, we show the efficient synthesis of a pharmaceutically significant 1,4-enyne. The present methodology can also be used for chemo- and regioselective direct deoxygenation of other alcohols. [ABSTRACT FROM AUTHOR]

The majority reactions of alkynes in the literature are reported to proceed via either structural σ-activation or catalytic π-activation of C≡C bonds. We skillfully designed novel methods for the catalytic σ-activation of C≡C bonds of alkynyl compounds. For terminal alkynyl compounds, σ-activation was achieved by silver(i)-catalyzed C–H functionalization. Whereas σ-activation of internal alkynes was accomplished by the generation of propargylic cations from propargylic alcohols under Lewis-acid catalysis. These σ-activated species have been successfully used for new C–C and C–heteroatom bond formation reactions. Plausible reaction pathways were proposed based on typical control experiments to help the readers to gain insights into reactions and for further discovery of new reactions based on this concept of catalytic σ-activation of C≡C bonds. [ABSTRACT FROM AUTHOR]

Keywords: catalysis; ligands; organic synthesis; silver; valorization EN catalysis ligands organic synthesis silver valorization 3200 3201 2 07/30/21 20210721 NES 210721 B Silver for the winner b ! GLO:BDBK/21jul21:cctc202100419-toc-0001.jpg PHOTO (COLOR): . gl Although they have long been considered inert in organic synthesis, silver catalysts started to emerge in the literature since the early 2000s and have now become a powerful tool for synthetic chemistry.[1,2] This lagging in silver-catalysis could be attributed mainly to the distinct reactivity profiles arising from the unique electronic and geometrical features of silver catalysts as compared to other transition metal catalysts. Complete switches of reaction products have been achieved by resulting to silver catalysts over other transition-metal catalysts or by fine-tuning the silver-ligand ratio, ligand libraries, counterions or the coordination geometry of the silver catalyst itself. [Extracted from the article]

The article presents a study which examines a novel silver-catalyzed isocyanide-alkyne cycloaddition. It states that the scope of internal alkynes that have been used in base-or copper-catalyzed procedures was further investigates to examine the generality of silver-catalyzed isocyanide-alkyne cycloaddition. It concludes that Ag2CO3 was discovered as a unique catalyst for isocyanides cycloaddition.

The catalytic intramolecular aromatic C–H alkenylation of arenes with non-activated ketone carbonyls has been realized for the first time, leading to the synthesis of antiviral 4-alkylene quinolin-2-ones, where the quaternary carbon adjacent to the ketone carbonyl plays an essential role in this catalytic reaction. [ABSTRACT FROM AUTHOR]

N‐Nosylhydrazones were discovered as the first generation of room‐temperature decomposable diazo surrogates, which led to the development of silver‐catalyzed [2+1] cyclopropenation of alkynes with unstable diazoalkanes. More information can be found in the Communication by X. Bi et al. on page 4756 ff. [ABSTRACT FROM AUTHOR]

Review: [348 refs. [ABSTRACT FROM AUTHOR]

A wide range of aromatic methyl ketones as well as aliphatic methyl ketones are subjected to the copper-catalyzed oxidative cleavage of the C(CO)-C(CH3) bond to yield the corresponding aldehydes.The oxidation terminates at the aldehyde stage and can be considered as an unprecedented dehydrogenation of saturated aliphatics. [ABSTRACT FROM AUTHOR]

A novel methodology for the reductive deoxyallenylation of sterically hindered propargylic alcohols such as (I), (III), and (V) is described. [ABSTRACT FROM AUTHOR]

An anti-markovnikov hydroazidation of terminal alkynes is described. This method is employed to a variety of functionalized substrates. The formed vinyl azides can be further converted to amides. [ABSTRACT FROM AUTHOR]

A broad variety of methylene compounds, including carbonyl, carboxyl, nitro, cyano, and sulfonyl group containing ones react with aryl isocyanides to form β-aminoenones, which are most often formed exclusively as E-isomers. [ABSTRACT FROM AUTHOR]

The first examples where TosMIC (II) acts as both an allenylative reagent and sulfonyl source in a cascade reaction are presented. [ABSTRACT FROM AUTHOR]

Review: 118 refs- + subrefs. [ABSTRACT FROM AUTHOR]

The article presents a chemical reaction for the alkyne-azide cycloaddition of diynes.

The article reports on modular synthesis of Sulfonyl Benzoheteroles by silver-Catalyzed Heteroaromatization of Propargylic Alcohols.

An environmentally friendly route towards fully substituted 4,5-dihydropyrroles is provided. [ABSTRACT FROM AUTHOR]

An abstract of the article "Silver-Catalyzed Cyclization of 2-Pyridyl Alkynyl Carbinols with Isocyanides: Divergent Synthesis of Indolizines and Pyrroles" by Xianyu Meng and colleagues is presented.

A chemo- and regioselective hydroazidation of differently substituted ethynylcarbinols is achieved by Ag(I)-catalyzed reaction with TmsN3 to yield 2-azidoallyl alcohols. [ABSTRACT FROM AUTHOR]

Application of this method is demonstrated by the trifluoromethylation of several bioactive drugs. [ABSTRACT FROM AUTHOR]

An unprecedented silver-catalyzed cross-coupling reaction between propargylic alcohols and isocyanides is described. [ABSTRACT FROM AUTHOR]

Ag2CO3 is described as robust catalyst for the [3 + 2] cycloaddition of isocyanide and terminal or internal alkynes to provide 2,3-disubstituted and 2,3,4-trisubstituted pyrroles. [ABSTRACT FROM AUTHOR]