474661-34-2

Upstream product

• 590-93-2 2-Butynoic acid 
• 619-42-1 4-methoxycarbonylphenyl bromide 
• 3609-53-8 methyl 4-acetylbenzoate 
• 614-45-9 tert-Butyl peroxybenzoate 
• 3034-86-4 4-ethynylbenzoic acid methyl ester 
• 619-44-3 methyl 4-iodobenzoate 
• 74-99-7 prop-1-yne 

Downstream Products

• 16882-08-9 bis(4-(methoxycarbonyl)phenyl)acetylene 
• 3645-00-9 terephthalic acid-(2-hydroxyethyl ester)-methyl ester 

Relevant academic research and scientific papers

Enantioselective Addition of α-Nitroesters to Alkynes

By using Rh–H catalysis, we couple α-nitroesters and alkynes to prepare α-amino-acid precursors. This atom-economical strategy generates two contiguous stereocenters, with high enantio- and diastereocontrol. In this transformation, the alkyne undergoes isomerization to generate a RhIII–π-allyl electrophile, which is trapped by an α-nitroester nucleophile. A subsequent reduction with In powder transforms the allylic α-nitroesters to the corresponding α,α-disubstituted α-amino esters.

A Pd-catalyzed domino Larock annulation/dearomative Heck reaction

A palladium-catalyzed domino Larock annulation/dearomative Heck reaction is developed, which delivers a range of tetracyclic indoline derivatives in moderate to excellent yields through a Larock annulation of N-bromobenzoyl o-iodoanilines with alkynes and a subsequent intramolecular dearomative Heck reaction. This protocol provides a straightforward route to structurally diverse indolines from readily available starting materials by forming two new rings and three chemical bonds in a single step.

Multi-Metal-Catalyzed Oxidative Radical Alkynylation with Terminal Alkynes: A New Strategy for C(sp3)-C(sp) Bond Formation

A new way for C(sp3)-C(sp) cross-coupling with terminal alkynes has been developed by using a multi-metal-catalyzed reaction strategy. Alkyl radicals generated from different approaches are able to couple with terminal alkynes by judicious selection of the catalyst combination. This reaction protocol offers an efficient alternative approach for the synthesis of substituted alkynes from terminal alkynes besides traditional Sonogashira coupling. Mechanistic studies have also been carried out to clarify the role of each metal catalyst in the radical alkynylation processes. The reactions were found to go through radical reaction pathways. Synergistic cooperation of the metal catalysts is the key for controlling the reaction selectivity of alkyl radicals toward C(sp3)-C(sp) bond formation.

Visible-Light-Mediated Photoredox-Catalyzed Regio- and Stereoselective Chlorosulfonylation of Alkynes

Herein, a one-step chlorosulfonylation of alkynes via a photocatalytic redox process is described. A variety of commercially available sulfonyl chlorides can be applied for the generation of sulfonyl radical species under visible-light irradiation. Regio- and stereoselective addition of the sulfonyl radical and chloride leads to the efficient formation of (E)-selective β-chlorovinyl sulfones from a broad range of terminal and internal alkynes. The reported method represents an operationally simple and mild way to furnish vinyl sulfones.

Direct Enantioselective α-Allylation of Unfunctionalized Cyclic Ketones with Alkynes through Pd-Amine Cooperative Catalysis

The first direct enantioselective α-allylation of unfunctionalized cyclic ketones using alkynes as an economical choice of reagent is reported. This transformation uses a simple procedure with commercially available palladium, chiral bisphosphine ligand and chiral amine catalysts, and affords valuable ketones with a α-tertiary stereocenter in good to high enantiopurity. In this transformation, a chiral palladium complex containing the (S)-DIFLUORPHOS ligand catalyzes the isomerization of alkynes into an electrophilic allylpalladium species, which is attacked by the enamine generated in situ from the condensation of (R)-prolinol with the ketone substrate.

Transformation of Carbonyl Compounds into Homologous Alkynes under Neutral Conditions: Fragmentation of Tetrazoles Derived from Cyanophosphates

Cyanophosphates (CPs) can be easily prepared from either ketones or aldehydes, and their reaction with NaN3-Et3N·HCl results in the formation of azidotetrazoles. Under microwave irradiation, successive fragmentation of the azidotetrazoles generates alkylidene carbenes that undergo [1,2]-rearrangement and are transformed into homologous alkynes. Treatment of ketone-derived CPs with TMSN3 and Bu2SnO as catalyst in toluene at reflux directly yields the corresponding internal alkynes, whereas the reaction of aldehyde-derived CPs with NaN3-Et3N·HCl in THF at reflux or TMSN3-Bu2SnO (cat.) in toluene at reflux provides homologous terminal alkynes in good yields. These reactions take place under neutral conditions and can be successfully extended to obtain alkynes that are not usually accessible from the corresponding carbonyl compounds by the Ohira-Bestmann or Shioiri procedures, which require basic conditions.

Stereoselective Photoredox-Catalyzed Chlorotrifluoromethylation of Alkynes: Synthesis of Tetrasubstituted Alkenes

A new photoredox-catalyzed chlorotrifluoromethylation reaction of internal arylalkynes under mild conditions using visible light has been developed. The reactions proceed with high levels of regio- and stereoselectivity and utilize commercially available CF3SO2Cl as both the CF3 and Cl source. In the mechanistic pathway for this process, generation of the CF3 radical and chloride ion occurs by Ir(ppy)3-photocatalyzed reductive decomposition of CF3SO2Cl. The synthetically important trifluoromethyl-substituted vinyl chlorides produced in this process can be readily transformed to 1,1-bis-arylalkenes by using Suzuki coupling.

Palladium-catalyzed allylic alkylation with internal alkynes to construct C-C and C-N bonds in water

A palladium-catalyzed system enabled efficient allylic alkylation with alkynes in water has been developed. This reaction presents an environmentally friendly strategy for constructing lots of allylic compounds with indolinones, ketones, amines as well as electron-rich aromatic compounds as nucleophiles. Moreover, the in situ formed arylallene intermediate adopting alkynes as starting materials omits the need for leaving groups and extra oxidants, showing high atom economy. The versatility of the developed reaction also lends itself to the incorporation of deuteriums by simply replacing H2O with D2O.

Stereodivergent coupling of aldehydes and alkynes via synergistic catalysis using Rh and Jacobsen's amine

We report an enantioselective coupling between α-branched aldehydes and alkynes to generate vicinal quaternary and tertiary carbon stereocenters. The choice of Rh and organocatalyst combination allows for access to all possible stereoisomers with high enantio-, diastereo-, and regioselectivity. Our study highlights the power of catalysis to activate two common functional groups and provide access to divergent stereoisomers and constitutional structures.

Stereodivergent Coupling of Aldehydes and Alkynes via Synergistic Catalysis Using Rh and Jacobsen's Amine

We report an enantioselective coupling between α-branched aldehydes and alkynes to generate vicinal quaternary and tertiary carbon stereocenters. The choice of Rh and organocatalyst combination allows for access to all possible stereoisomers with high ena