Base-Promoted One-Pot Four-Component Domino Strategy Involving Aldehydes and Ketones to Access Multifunctionalized Dihydropyridinones.

The synthesis of multifunctionalized dihydropyridinones from aldehydes and ketones involves at least a three-step process, making route shortening a challenging task, especially in achieving a one-pot four-component synthesis via aldehydes and ketones precondensation. Herein, we discovered a [1 + 2 + 1 + 2] four-component domino cyclization reaction, a novel concept in 4CRs with commercially available ketones and aldehydes, which by initially combining aldehydes and ketones with Meldrum's acid and ammonium acetate (NHOAc), respectively, they give dihydropyridones (>110 examples). This transformation features inexpensive additives and readily available starting materials, making it appropriate for rapid access to relevant pharmaceutical molecules containing dihydropyridinone-derived heterocycles.

Cu(II)/Base Synergistic Promoted [2 + 1 + 3] Cyclization of Cyclic Ketones with α,β-Unsaturated Aldehydes/Ketones and NHI to Access Fused Pyridines.

Herein, a practical three-component [2 + 1 + 3] cyclization of various cyclic ketones with α,β-unsaturated aldehydes/ketones and ammonium iodide (NHI) to access highly functional fused pyridines has been developed. The features of this transformation include mild reaction conditions, readily available starting materials, and excellent chemoselectivity. This protocol is compatible with various functional groups, and the preliminary studies on the mechanism of the reaction are also provided.

Base-Promoted Annulated Aromatization of Aryl Acetylenes with Dimethyl Sulfoxide to Access Symmetrical/Unsymmetric -Terphenyl.

A protocol for selective and efficient synthesis of symmetrical and unsymmetrical -terphenyls is presented among aryl acetylene and DMSO in the presence of KOH and methanol. In this reaction, two molecules of aryl acetylene contribute four carbons, and DMSO, as a dual carbon donor, provides two carbons to a new aromatic ring. This protocol can be tolerated for the electron-donating or disubstituted phenylacetylenes as well as the heterocyclic acetylene derivatives.

Catalyst-Free, Zn-Mediated Decarboxylative Coupling of Chlorostibines to Access Alkylstibines with Stable C(sp)-Sb Bonds.

Herein, decarboxylative C(sp)-Sb coupling of aliphatic carboxylic acid derivatives with chlorostibines to access alkylstibines has been achieved. This catalyst-, ligand-, and base-free approach using zinc as a reductant affords various kinds of benzyldiarylstibines and other monoalkyldiarylstibines and tolerates various functional groups, including chlorine, bromine, hydroxyl, amide, sulfone, and cyano groups. The late-stage modification and the gram-scale experiments illustrate its potential application.

Nickel-Catalyzed C(sp)-Sb Coupling of Chlorostibines with Unactivated Alkyl Chlorides and In Vitro Anticancer Activity of Products.

In this study, we present a nickel-catalyzed reductive C(sp)-Sb coupling of unactivated alkyl chlorides with chlorostibines. This approach is highly versatile, tolerating various functional groups such as acetal, alkene, nitrile, amine, ester, silyl ether, thioether, and various heterocyclic compounds. Notably, the late-stage modification of bioactive molecules and the satisfactory anticancer activity against cancerous MDA-MB-231 also demonstrate the potential application.

Trivalent Organostibines: Sb,N Ligands in Double N-Arylation of Primary Amines toward Functionalized Carbazoles.

A Sb,N ligand () for Pd-catalyzed double N-arylation of primary amines was developed. This trivalent ligand , containing a 5,6,7,12-tetrahydrodibenzo[,][1,5]azastibocine skeleton and stable under air and moisture, could be synthesized facilely on a gram scale from chlorostibine () and cyclopentylmagnesium bromide. showed excellent catalytic performance in Pd(dba)-catalyzed double N-arylation of 2,2'-dibromo-1,1'-biphenyl () with primary amines (), affording functionalized carbazoles in good yields.

Recent Progress on Nitrogen-Rich Energetic Materials Based on Tetrazole Skeleton.

Development of nitrogen-rich energetic materials has gained much attention because of their remarkable properties including large nitrogen content and energy density, good thermal stability, low sensitivity, good energetic performance, environmental friendliness and so on. Tetrazole has the highest nitrogen and highest energy contents among the stable azoles. The incorporation of diverse explosophoric groups or substituents into the tetrazole skeleton is beneficial to obtain high-nitrogen energetic materials having excellent energetic performance and suitable sensitivity.

Process-Divergent Syntheses of 4- and 5-Sulfur-Functionalized 1,2,3-Triazoles via Copper-Catalyzed Azide-Alkyne Cycloadditions of 1-Phosphinyl-2-sulfanylethynes.

4-Sulfanyl-substituted 1,2,3-triazoles were provided regioselectively with good yields and broad scope via consecutive -BuOK-promoted dephosphinylation of 1-phosphinyl-2-sulfanylethynes and copper-catalyzed azide-alkyne cycloadditions (CuAAC) with alkyl azides. Unsymmetrically substituted ditriazoles were successfully obtained using a tandem dephosphinylative CuAAC protocol with diazides. Direct CuAAC of the 1-phosphinyl-2-sulfanylethynes with azides afforded regioisomeric mixtures of 4-phosphinyl-5-sulfanyl- and 5-phosphinyl-4-sulfanyl-1,2,3-triazoles that were easily separable from one another.

Copper-Catalyzed Cyclization of 2-Alkynylanilines to Give 2-Haloalkoxy-3-alkyl(aryl)quinolines.

Herein we describe a method to produce 2-haloalkoxy-3-substituted quinolines via the cyclization of 2-alkynylanilines with TMSCF and THF. This synthetic method uses inexpensive and easy-to-handle TMSCF and employs a commercially available CuI catalyst to transform a broad range of 2-alkynylanilines into versatile 2-difluoromethoxy-3-substituted quinolines and 2-iodoalkoxy-3-substituted quinolines with excellent chemoselectivity.

Selectfluor-Promoted Reactions of Aryl Methyl Ketones with Dimethyl Sulfoxide to Give 2,5-Diacylthiophenes and β-Acyl Allylic Methylsulfones.

In this paper, a convenient synthesis of 2,5-diacylthiophenes and β-acyl allylic methylsulfones from aryl methyl ketones with dimethyl sulfoxide (DMSO) through Selectfluor-promoted cascade cyclization and cross-coupling reactions by simple solvent modification is described. This method enables the formation of new C-C and C-S bonds via the selection of different solvent ratios, in which DMSO molecules as synthons can be selectively introduced into methyl ketones. The features of this transformation include readily available starting materials, excellent chemoselectivity, and good functional group tolerance.

DTBP-mediated cross-dehydrogenative coupling of 3-aryl benzofuran-2(3)-ones with toluenes/phenols for all-carbon quaternary centers.

We have developed a transition-metal free protocol for efficient cross-dehydrogenative coupling of 3-aryl benzofuran-2(3)-ones and toluenes/phenols using DTBP as an oxidant. A diverse range of 3-aryl benzofuran-2(3)-ones, toluenes, and phenols undergo C-H bond cleavage to generate all-carbon quaternary centers in good yields, making this protocol useful for the synthesis of complex molecules. A gram scale experiment was performed in good yield.

Recent Advances in the Use of Dimethyl Sulfoxide as a Synthon in Organic Chemistry.

Dimethyl sulfoxide (DMSO), as extremely important aprotic polar solvent and reaction medium, has attracted widespread attention from chemists in recent years due to its wide range of uses and the multiple functions it displays in various chemical processes. Especially in the past decade, dimethyl sulfoxide has become increasingly favored as a synthon in organic chemistry, resulting in great progress in this research field. In this context, this review provides a comprehensive summary of the literature on the recent progress in organic synthesis using dimethyl sulfoxide as a synthon, covering all the reports from 1 January 2016 to 11 May 2022.

Co-Catalyzed Dual C5/C8-H Bond Functionalization of Imidazo[1,2]pyrazines with Disulfides and Grignard Reagents.

An efficient difunctionalization at C5/C8 of imidazo[1,2]pyrazines has been developed using disulfides and Grignard reagents under cheap cobalt catalysis. This one-pot, two-step, three-component transformation is performed under mild conditions; various Grignard reagents (aryl and alkyl) and disulfides are tolerated. Mechanistic studies and control experiments demonstrate this reaction proceeded via an anionic intermediate.

Copper-Catalyzed Regioselective Iodoformylation of Terminal Alkynes to Access Versatile Electrophiles ()-β-Iodo-α,β-Unsaturated Aldehydes.

Herein, we describe a method for synthesizing ()-β-iodo-α,β-unsaturated aldehydes via the iodoformylation of terminal alkynes with TMSCF and NaI. This synthetic method uses inexpensive and easy-to-handle chemical feedstocks and employs a commercially available CuI catalyst. It can transform a broad range of terminal alkynes into bis-electrophile ()-β-iodo-α,β-unsaturated aldehydes with excellent chemoselectivity, regioselectivity, and stereoselectivity.

Base-Promoted Reactions of Organostibines with Alkynes and Organic Halides to Give Chalcogenated ()-Olefins and Ethers.

Herein, with air-stable chalcogenated stibines (-ER) as organometallic chalcogenating reagents, we developed base-promoted ()-hydrochalcogenation of alkynes with DMSO/DMSO- as hydrogen/deuterium sources, giving chalcogenated ()-olefins in good yields and with excellent regioselectivity. These reagents, easily synthesized from halostibines with generated [Zn(ER)] at room temperature within a few minutes, could be also used in the base-promoted C()-S(Se) cross-coupling with C()-X and copper-catalyzed C()-S(Se) cross-coupling with C()-X (X = F, CI, Br, I) under mild conditions. This protocol could also be simply extended to organobismuth complexes (-ER) with good functional tolerance.

Zirconium-Based Catalysts in Organic Synthesis.

Zirconium is a silvery-white malleable and ductile metal at room temperature with a crustal abundance of 162 ppm. Its compounds, showing Lewis acidic behavior and high catalytic performance, have been recognized as a relatively cheap, low-toxicity, stable, green, and efficient catalysts for various important organic transformations. Commercially available inorganic zirconium chloride was widely applied as a catalyst to accelerate amination, Michael addition, and oxidation reactions.

Copper-Catalyzed Regioselective Olefination and Trifluoromethylation of Carboxylic Acids To Give ()-Trifluoromethyl Enol Esters.

Herein, we describe a method to produce ()-trifluoromethyl enol esters via the olefination and trifluoromethylation of carboxylic acids with TMSCF. This synthetic method uses inexpensive and easy-to-handle TMSCF. It employs a commercially available CuCl catalyst to transform a broad range of carboxylic acids into versatile ()-trifluoromethyl enol esters with good regio- and stereoselectivity.

CFSONa-Mediated Five-Component Carbonylation of Triarylboroxines with TMSCF and THF/LiOH/NaI to Give Aroyloxyalkyl Iodides.

Herein, we developed an efficient and transition-metal-free multicomponent coupling reaction for the synthesis of aroyloxyl alkyl iodides. In the reaction among 2,4,6-triarylboroxines, THF, TMSCF, LiOH, and NaI, five-component reactions could be precisely controlled by modulating CFSONa, supplying one type of aroyloxyl alkyl iodides in moderate to high yields. The reaction exhibits good functional group tolerance and a wide substrate scope and can be easily transformed into other useful compounds.

Synthesis of (Deoxy)difluoromethylated Phosphines by Reaction of RP(O)H with TMSCF and Their Application in Cu(I) Clusters in Sonogashira Coupling.

RPCFH ligands and their RP(O)CFH precursors were synthesized from RP(O)H with TMSCF by simply modulating the HO concentration via deoxydifluoromethylation and difluoromethylation. The air sensitive RPCFH phosphines can be stabilized in Cu(I) clusters as ligands. Within these Cu(I) clusters, the Sonogashira cross-coupling reaction can proceed fast and efficiently using terminal alkynes and aryl iodides within 15 min at room temperature under air to give a variety of diaryl(alkyl)acetylenes in good yields (49 examples, yields of ≤99%).

FeO(OH)@C-Catalyzed Selective Hydrazine Substitution of p-Nitro-Aryl Fluorides and their Application for the Synthesis of Phthalazinones.

An efficient hydrazine substitution of p-nitro-aryl fluorides with hydrazine hydrates catalyzed by FeO(OH)@C nanoparticles is described. This hydrazine substitutions of p-nitro-aryl fluorides bearing electron-withdrawing groups proceeded efficiently with high yield and selectivity. Similarly, hydrogenations of p-nitro-aryl fluorides containing electron-donating groups also smoothly proceeded under mild conditions.

One-pot synthesis of phosphorylnaphth[2,1-]oxazoles and products as P,N-ligands in C-N and C-C formation.

Phosphanylnaphtho[2,1-]oxazoles were synthesized successfully through one-pot phosphonation of naphthoquinone with diaryl(alkyl)phosphine oxides and Cu-catalyzed oxidative condensation with imines, followed by methylation and reduction. Upon applying 4-phosphanylnaphtho[2,1-]oxazole as a P,N-chelating ligand, Pd-catalyzed C-N formation of amines or nitrobenzene as well as Ni-catalyzed C-C formation and the synthesis of quinoline proceeded successfully. The reaction was facilely scaled up to give -benzylaniline 15a in a gram scale synthesis.

Pd-Catalyzed Cross-Coupling of -Aryl Stibines with Halogenomethyl Arenes to Give Unsymmetirc Diarylmethanes.

Herein, we describe a general method for the synthesis of unsymmetric diarylmethanes from (hetero)aryl methyl halides and -aryl stibines. This protocol shows a broad substrate scope and a good functional group tolerance. Drug molecules, including beclobrate and bifemelane , and drug derivatives, including celecoxib , ibuprofen , and probenecid , were efficiently synthesized on a gram scale.

Cu-Catalyzed Dual C-O Bonds Cleavage of Cyclic Ethers with Carboxylic Acids, NaI, and TMSCF to Give Iodoalkyl Ester.

Herein, by dual C-O bond cleavage of cyclic ethers with Cu catalysis, we eventually led to the development of a selective three-component coupling of commercially available chemicals, carboxylic acids, ethers, and halogens to synthesize more than 70 iodoalkyl esters in the presence of TMSCF. This allows for the concise synthesis of highly functionalized iodoalkyl esters directly. And the synthetic insect pheromones were also disclosed.

A pH-Dependent rhodamine fluorophore with antiproliferative activity of bladder cancer in Vitro/Vivo and apoptosis mechanism.

Herein, 26 rhodamine fluorophores were synthesized from readily available Rh-6G and relative amines at room temperature with good selectivity, functional groups compatibility and high yields. We found that one of them 3f showed pH-dependent anticancer bioactivity, with cell viability of 68.4% under pH 6.