Dual Role of Alkynyl Bromides in One-Step Synthesis of Bromo-Substituted Alkynyl Sulfides

An atom-economical and environmentally friendly method for synthesis of bromo-substituted alkynyl sulfides has been developed. In the absence of any additive, alkynyl bromides could react with tetrahydrothiophene to give bromo-substituted alkynyl sulfides in moderate to perfect yields.     

The first broad application of alkynyl sulfides as dienophiles in cobalt(I)-catalyzed Diels-Alder reactions

The cobalt(I)-catalyzed Diels-Alder reaction of nonactivated aryl alkynyl sulfides with acyclic 1,3-dienes generates dihydroaromatic vinyl sulfides under very mild reaction conditions, and these products can be oxidized with mild oxidants to the corresponding diaryl sulfides in good overall yields. The steric and electronic effects of substituents on the aryl, as well as on the alkynyl, moieties of the aryl alkynyl sulfide are discussed. While the cobalt catalyst system is quite efficient in converting alkynyl sulfides to the Diels-Alder adducts, the transformation of the corresponding aryl alkynyl sulfoxides and sulfones under similar mild reaction conditions gave only moderate yields of the desired adducts.     

Photochemical Dual‐Catalytic Synthesis of Alkynyl Sulfides

A photochemical dual‐catalytic cross‐coupling to form alkynyl sulfides via C(sp)−S bond formation is described. The cross‐coupling of thiols and bromoalkynes is promoted by a soluble organic carbazole‐based photocatalyst using continuous flow techniques. Synthesis of alkynyl sulfides bearing a wide range of electronically and sterically diverse aromatic alkynes and thiols can be achieved in good to excellent yields (50–96 %). The simple continuous flow setup also allows for short reaction times (30 min) and high reproducibility on gram scale. In addition, we report the first application of photoredox/nickel dual catalysis towards macrocyclization, as well as the first example of the incorporation of an alkynyl sulfide functional group into a macrocyclic scaffold.     

Ruthenium-catalyzed [2+2] cycloadditions of alkynyl sulfides and alkynyl sulfones

Ruthenium-catalyzed [2+2] cycloadditions of bicyclic alkenes with alkynyl sulfides and alkynyl sulfones were investigated. The sulfide and sulfone moieties were found to be compatible with the Ru-catalyzed cycloadditions, giving the corresponding cyclobutene cycloadducts in good yields. The sulfonyl-containing cycloadducts can be transformed into a variety of products that are difficult to obtain via direct cycloaddition.     

Synthesis and properties of 1-methylthiopropargylammonium salts and their use as key precursors to sulfur-containing enediynes

1-methylthiopropargylammonium salts were synthesized in a highly efficient manner by reaction of alkynyl S,N-acetals with methyl triflate. Reactions of the 1-methylthiopropargylammonium salts with Grignard reagents gave propargyl sulfides or allenyl sulfides, whereas the reaction with organocopper reagents led to exclusive formation of allenyl sulfides regardless of the nature of substituents on the acetylenic carbon. The salts undergo self-dimerization reactions when treated with organolithium and lithium amide bases.     

Alkynyl derivatives of selenophene II. Addition of thiols to selenienyl alkynyl ketones

The reaction of selenienyl alkynyl ketones with thiophenol and butyl mercaptan gave good yields of selenienylketovinyl sulfides. The corresponding sulfones were obtained from some of the sulfides by oxidation with hydrogen peroxide. The IR spectra of the synthesized compounds are discussed.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1637–1639, December, 1971.     

Metal-Free Oxidative Trifluoromethylthiolation of Terminal Alkynes with CF(3)SiMe(3) and Elemental Sulfur

A metal-free oxidative trifluoromethyl-thiolation of terminal alkynes using readily available CF(3)SiMe(3) and elemental sulfur at room temperature has been developed. This reaction provides an efficient and convenient method for the preparation of alkynyl trifluoromethyl sulfides bearing a wide range of functional groups. Preliminary investigation revealed that elemental sulfur instead of air acted as the oxidant.     

Highly Stereoselective Synthesis of 1,2‐Diorganothio‐1‐alkenes via Hydrothiolation of Alkynyl Sulfides Catalyzed by Cesium Hydroxide

In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive (Z)‐1,2‐diorganothio‐1‐alkene in excellent yields. It could provide a new and expedient way for the preparation of symmetrical and unsymmetrical (Z)‐1,2‐diorganolthio1‐1‐alkenes.     

Copper‐Catalyzed Extended Pummerer Reactions of Ketene Dithioacetal Monoxides with Alkynyl Sulfides and Ynamides with an Accompanying Oxygen Rearrangement

The first examples of metal‐catalyzed extended Pummerer reactions through the activation of sulfoxides are described. The copper‐catalyzed reactions of ketene dithioacetal monoxides with alkynyl sulfides and ynamides provided a wide variety of γ,γ‐disulfanyl‐β,γ‐unsaturated carbonyl compounds with an accompanying oxygen rearrangement. The products can be easily converted into 1,4‐dicarbonyl compounds and substituted heteroaromatics. DFT calculations and mechanistic experiments revealed a new interesting stepwise addition/oxygen rearrangement mechanism.     

New Method of Synthesis of β-Haloalkyl Alkynyl Sulfides: Reaction of Alkynesulfenamides with Olefins in the Presence of Phosphoryl Halides

Reactions of alkynelsufenamides with olefins (such as cyclohexene, norbornene, 1-hexene, 1-octene, allylbenzene, and styrene) in the presence of phosphoryl halides (POCl₃, POBr₃) afforded 70–95% of β-halo-substituted alkyl alkynyl sulfides. The reactions with cyclohexene and norbornene are characterized by trans stereoselectivity. Alkynylsulfenylation of terminal alkyl- and benzylacetylenes occurs in a regioselective fashion with predominant formation of the corresponding anti-Markownikoff adducts, while the addition to styrene yields halogen-containing sulfides according to the Markownikoff rule.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 977–982.Original Russian Text Copyright © 2005 by Beloglazkina, Belova, Dubinina, Garkusha, Buryak, Zyk.     

A convenient synthetic route for alkynylselenides from alkynyl bromides and diaryl diselenides employing copper(I)/imidazole as novel catalyst system

A mild, convenient, and effective strategy is developed for the synthesis of alkynyl selenides from alkynyl bromides and respective diselenides using CuI/imidazole as a novel catalyst system with Mg as additive. The procedure affords the title compounds in moderate to good yield (51-89%). The main advantages of the protocol include the use of inexpensive copper catalyst, a novel Cu(I)/imidazole combination, and good yield of the products.     

金催化的炔烃羟基化反应: 合成2取代苯并呋喃化合物

本文报道了一种以邻炔基苯酚为原料,通过金催化的炔烃羟基化反应合成2取代苯并呋喃的方法. 该方法可以在温和的条件下快速以高产率得到各种2取代苯并呋喃. 关键前体邻炔基苯酚可以很容易由Sonogashira 反应制备.     

An Arylation Strategy to Propargylamines: Catalytic Asymmetric Friedel–Crafts‐type Arylation Reactions of C‐Alkynyl Imines

The first arylation strategy for the synthesis of enantioenriched propargylamines is disclosed. This approach, which is complementary to previous alkynylation and alkylation strategies, involves a C(sp²)?C(sp³) bond formation, and is based on the first asymmetric Friedel–Crafts‐type arylation reaction of C‐alkynyl imines. Asymmetric Friedel–Crafts reactions with electron‐deficient phenols, a longstanding unsolved challenge, have thus been realized for the first time, enabled by the combination of our recently introduced C‐alkynyl N‐Boc‐protected N,O‐acetals as electrophiles and chiral phosphoric acids as catalysts. The synthetic utility of the resulting structurally diverse and polyfunctional chiral propargylamines was demonstrated by a series of selective transformations, including controlled reduction of the alkynyl group and iterative cross‐couplings.     

Synthesis, characterization, and structures of oxovanadium(V) complexes of Schiff bases of beta-amino alcohols as tunable catalysts for the asymmetric oxidation of organic sulfides and asymmetric alkynylation of aldehydes

Oxovanadium(V) complexes and with general formula VO(L3*)(OR5) were prepared in quantitative yields in alcohol (R5OH) from reactions of VO(O-i-Pr)3 and tridentate Schiff bases of beta-amino alcohols having one or two stereogenic centers, (HO)C*(R1)(R2)C*H(R3)N[double bond, length as m-dash]CH(2-OH-3,5-R4(2)-C6H2) (H2L3*). The alkoxy OR5 ligand exchanges readily with the alcoholic molecule in the solvent. Crystal structures of and were determined to be five-coordinate square pyramidal monomers. However, 1H NMR spectra of the complexes reveal two sets of signals, indicating the presence of two isomers in solution. The two isomers are suggested to be the endo/exo pair or the monomer/dimer pair. Asymmetric oxidations of methyl phenyl sulfide catalyzed by catalyst precursors were demonstrated to afford the chiral sulfoxide in yields and ee values similar to those obtained from the in situ-formed catalytic systems of VO(acac)2 and corresponding Schiff base ligands. Complexes and are also good catalysts for asymmetric alkynyl additions to aldehydes. Structural differences between the oxovanadium complexes, for inducing high stereoselectivities in the asymmetric oxidation of organic sulfides and the asymmetric alkynyl addition to aldehydes, are rationalized.     

The application of nanostructured transition metal sulfides as anodes for lithium ion batteries

With wide application of electric vehicles and large-scale in energy storage systems, the requirement of secondary batteries with higher power density and better safety gets urgent. Owing to the merits of high theoretical capacity, relatively low cost and suitable discharge voltage, much attention has been paid to the transition metal sulfides. Recently, a large amount of research papers have reported about the application of transition metal sulfides in lithium ion batteries. However, the practical application of transition metal sulfides is still impeded by their fast capacity fading and poor rate performance. More well-focused researches should be operated towards the commercialization of transition metal sulfides in lithium ion batteries. In this review, recent development of using transition metal sulfides such as copper sulfides,molybdenum sulfides, cobalt sulfides, and iron sulfides as electrode materials for lithium ion batteries is presented. In addition, the electrochemical reaction mechanisms and synthetic strategy of transition metal sulfides are briefly summarized. The critical issues, challenges, and perspectives providing a further understanding of the associated electrochemical processes are also discussed.     

Copper-mediated N-alkynylation of carbamates, ureas, and sulfonamides. A general method for the synthesis of ynamides

[reaction: see text] A general amination strategy for the N-alkynylation of carbamates, sulfonamides, and chiral oxazolidinones and imidazolidinones is described. A variety of substituted ynamides are available by deprotonation of amides with KHMDS followed by reaction with CuI and an alkynyl bromide.     

Synthesis and structure of 1‐phospholyl‐ and di(1‐phospholyl)acetylenes and the corresponding sulfides

The acetylenes possessing one and two 1‐phospholyl groups were synthesized by reaction of the alkynyl Grignard reagents with the 1‐chlorophosphole and converted to the corresponding phosphole sulfides. Reaction of the 1‐phenylethynylphosphole sulfide with CpCo(CO)₂ resulted in η⁴‐complexation on the phosphole moiety. The structures of the di(1‐phospholyl)acetylene disulfide and the [η⁴‐(1‐phenylethynylphosphole sulfide)]cobalt(I) complex were characterized by X‐ray crystallography. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:344–349, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20230     

Functionalised butanediacetal-protected 1,2-diols as suitable partners for Pd-catalysed cross-coupling reactions

A new method for the synthesis of dienes and enynes containing chiral 1,2-diols is described. The strategy is based on the Pd-catalysed cross-coupling reactions of a series of vinyl and alkynyl asymmetric butanediacetal-protected building blocks. After the coupling, removal of the protecting group leads to the desired functionalised dienes and enynes.     

Green and combinational method towards clickable alkynylated cellulose fibers (ACFs)

This paper presents an environmentally friendly strategy to obtain alkynylated cellulose fibers (ACFs), a versatile platform for tailoring cellulose by robust click reaction. This strategy is based on the integration of two efficient reactions: selective oxidation of cellulose fibers by sodium periodate (NaIO₄) generating dialdehyde cellulose fibers and subsequent Schiff base reaction with 3-ethynylaniline yielding alkynylated cellulose fibers (ACFs). The alkynyl moieties introduced into ACFs were simply transferred with azido compounds under Cu(I) catalysis and mild conditions. The content of alkynyl groups of ACFs was found to be as high as 3.0 mmol/g. Fourier transform infrared spectroscopy (FTIR) showed that the selective oxidation of cellulose fibers generated aldehyde groups and the Schiff base reaction resulted in the incorporation of ethynyl groups and benzene rings into cellulose fibers. FTIR and X-ray photoelectron spectroscopy results confirmed the successful click reaction between ACFs and 4-azidobenzoic acid. This clickable platform would serve as a versatile starting precursor for finely tuning cellulose fibers for advanced applications.     

Ga(III)-catalyzed cycloisomerization strategy for the synthesis of icetexane diterpenoids: total synthesis of (+/-)-salviasperanol

[reaction: see text] A general approach to the tricyclic core of the icetexane natural products via the cycloisomerization of alkynyl indenes using GaCl(3) is presented. This strategy provides an efficient synthesis of the natural product salviasperanol and sets the stage for access to other members of this family of diterpenoids.