Higher Order Cuprate Species( Ⅱ )——Stereospecific Carbocupration of Terminal Alkynes and Its Synthetic Utility for ( ± )-Ipsenol and (E)-β-Farnesene

The stereospecific carbocupration of terminal alkynes via higher order cuprates to give 1,1'-disubstituted olefins with 99% configuration purity is described. Its synthetic utility as a general method for the preparation of substituted olefins is further illustrated by the direct synthesis of (±)-ipsenol and (E)-β-farnesene with highly geometric purity of the carbon-carbon double bond.

Hydroarylation of terminal alkynes with arylboronic acids catalyzed by low loadings of palladium

The hydroarylation reaction of terminal alkynes with arylboronic acids catalyzed by low(400 ppm) loadings of palladium has been developed. The reaction is broad in scope and high-yielding, even on multigram scale. It is suitable for the synthesis of alkenes labeled with deuterium, and for the late-stage modification of bioactive molecules.

Mercurous Chloride Catalyzed Mannich Condensation of Terminal Alkynes with Secondary Amines and Aldehydes

Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.

Platinum-Catalyzed Asymmetric Ring-opening Reaction of Oxabenzonorbornadiene with Terminal Alkynes

A novel platinum-catalyzed asymmetric ring-opening reaction of oxabenzonorbornadiene with terminal alkynes is described.The reaction affords optically active cis-2-alkynyl-1,2-dihydronaphthalen-1-ols in moderate yields with good enantioselectivity in the presence of catalytic amounts of Pt(COD)Cl_(2)/(S)-BINAP and an excess of zinc powder.The products were obtained exclusively with the relative cis-configuration of the ring substituents and the prevalent(1R,2S)-configuration of the stereocenters,as determined by single crystal X-ray diffraction analysis.

Specific cross-dimerization of terminal alkynes via Pd/TMEDA catalysis

The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,and organic functional materials,etc.However,due to the inherent issues of the stereo-,regio-,and chemoselectivity,the strategy is less explored and remains problematic in substrate scope,selectivity,and screening of catalytic system,etc.Herein,a specific cross-dimerization of terminal alkynes is developed under Pd/TMEDA catalysis,which produces a series of gem-1,3-enynes(58 examples)in totally moderate to high yields with outstanding functional group tolerance.A cyclopalladium compound might be the key imtermediate,which performs anti-addition-carbometallation,and leads to the exclusive cross-selectivity.The unprecedented features of the reaction,such as anti-addition-carbometallation,easy control of selectivity,wide range of the donor alkynes,and very simple catalytic conditions,allow it not only a facile and functionally diverse synthesis of 1,3-enynes,but also a substantial progress for the textbook reaction.

Microwave-enhanced Mannich Condensation of Terminal Alkynes, Primary Amines with Paraformaldehyde on Cuprous Iodide Doped Alumina under Solvent Free Conditions

A microwave enhanced, solventless Mannich condensation of terminal alkynes, primary amines with paraformaldehyde on cuprous iodide doped alumina has been investigated. The structures of products depend on the ratio of alkyne to amine and paraformaldehyde.

FeCl3- and GaCl3-Catalyzed Dehydrative Coupling Reaction of Chromone-Derived Morita-Baylis-Hillman Alcohols with Terminal Alkynes

FeCl3- and GaCl3-catalyzed dehydrative coupling reactions of chromone-derived Morita-Baylis-Hillman （MBH） alcohols with terminal alkynes were developed. The reactions provided exclusively a-regioselective and acetylene-substituted products in good yields.

On-surface construction of low-dimensional nanostructures with terminal alkynes: Linking strategies and controlling methodologies

Bottom-up approach to constructing low-dimensional nanostructures on surfaces with terminal alkynes has drawn great interest because of its potential applications in fabricating advanced functional nanomaterials. The diversity of the achieved products manifests rich chemistry of terminal alkynes and hence careful linking strategies and proper controlling methodologies are required for selective preparations of high-quality target nanoarchitectures. This review summarizes various on-surface linking strategies for terminal alkynes, including non-bonding interactions as well as organometallic and covalent bonds, and presents examples to show effective control of surface assemblies and reactions of terminal alkynes by variations of the precursor structures, substrates and activation modes. Systematic studies of the on-surface linkage of terminal alkynes may help efficient and predictable preparations of surface nanomaterials and further understanding of surface chemistry.

Studies on sulfinatodehalogenation XVI.Sodium dithionite-initiated addition of perfluoroalkyl iodides to terminal alkynes

Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new method for the addition of perfluoroalkyl iodides to alkynes. Under the same con- dition, in the presence of 1-hexyne perfluoroalkyl bromide and 1,1,1-trichlorotrifluoroethane reacted only to give sulfinates as the major products. A radical mechanism was proposed for the addition reaction.

A Facile Stereospecific Synthesis of 1, 3-Enynylsulfides via Sonogashira Coupling of （E）-a-Iodovinyl Sulfides with 1-Alkynes

（E）-α-Iodovinyl sulfides 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol % of Pd（PPh3）4 and 10 mol % of CuI to afford the corresponding 1, 3-enynylsulfides 3 stereospecifically in high yields.

A facile stereospecific synthesis of (Z)-2-sulfonyl-substituted 1,3-enynes via Sonogashira coupling of (E)-α-iodovinyl sulfones with 1-alkynes

（E）-α-Iodovinyl sulfones 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol% of Pd（PPh3）4 and 10 mol% of CuI to stereospecifically afford the corresponding （Z）-2-sulfonyl-substituted 1,3-enynes 3 in high yields.

Organic Polyvalent Iodinc Reagents-Promoted Coupling Reaction of 1-Alkynes

Teminal alkynes couple smoothly in the presence of PhI(OAc)2 or PhI(OH)OTs.catalytie Cul and base. affording conjugated diynes.

A new synthesis of alkynyl tellurides promoted by CsOH and 4 MS

The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4 A molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reaction mixture was stirred for 2.0 h. Alkynyl tellurides were obtained in about 90% yields by flash chromatography.

Recent advances in catalytic conversion of carbon dioxide to propiolic acids over coinage-metal-based catalysts

The conversion of inexpensive,available C1 feedstock of carbon dioxide(CO_(2))into value-added fine chemicals via homogeneous or heterogeneous catalysis has attracted great recent interest.Coinagemetal-based(Cu,Ag,and Au)catalysis has emerged as a synthetic strategy for a wide range of organic chemical reactions in past decades.In coinage-metal-catalyzed carboxylation,CO_(2)is adopted as a carboxylation reagent,while coinage-metal salts,complexes,and nanoparticles(NPs)serve as a Lewis acid catalyst to activate unsaturated chemicals,particularly alkynes.This mini-review focuses on the recent advances of coinage-metal-catalyzed carboxylation of terminal alkynes with CO_(2).Other respects,such as the role of bases,the influence of trace water,and solvent effects are also highlighted.

Facile synthesis of N-doped graphene encapsulated Ni@N/C catalyst and its catalysis for highly selective semi-hydrogenation of alkynes

Although precious transition metals such as palladium,platinum,and iridium are widely used in hydrogenation reactions,the earth-abundant transition metal-catalyzed highly selective semi-hydrogenation of terminal alkynes to terminal alkenes remains poorly developed and a challenge.Herein we demonstrate the excellent selective,cost-effective semi-hydrogenation of terminal alkynes via a novel graphene encapsulated Ni@N/C catalyst.The graphene layer encapsulated nano-catalyst Ni@N/C could significantly avoid metal leaching and improve the stability of the catalyst.The strong interaction of nitrogen with the Ni nanoparticles regulates the activity of Ni towards selective semi-hydrogenation of terminal alkynes.Substrates having un-functionalized as well as functionalized substituents,and substrates having sensitive functional groups(olefins,ketones)which pose a challenge to hydrogenate,were semi-hydrogenated with excellent conversion(up to 99%)and selectivity(up to 99%)under optimized reaction conditions.

A Facile Synthetic Route to New Fluorinated Building-Blocks of 1-Fluoroalkynes and 1-Fluorodiynest

A facile and direct fluorination process of alkynes and diynes was developed, in the presence of n-butyllithium, the reaction of a series of terminal alkynes and diynes with the electrophilic fluorinating reagent （NFSI） proceeded to afford various 1-fluoroalkynes and 1-fluoro-l,3-diynes in moderate to high yields.

Sonogashira Coupling Reaction with Palladium Powder and Potassium Fluoride in Methanol

A Sonogashira coupling reaction of aromatic halides with terminal alkynes in the presence of palladium powder, potassium fluoride, cuprous iodide and triphenylphosphine in methanol, giving the corresponding coupling products aryl alkynes in good to excellent yields, was investigated.

Glaser Coupling Reaction without Organic Solvents and Bases under Near-critical Water Conditions

A Glaser coupling reaction of terminal alkynes in the presence of cupric chloride without organic solvents and bases under near-critical water has been developed.