1007597-67-2

Upstream product

• 1907-65-9 N-butyl-4-toluenesulfonamide 
• 536-74-3 phenylacetylene 
• 932-87-6 1-Bromo-2-phenylacetylene 
• 98-59-9 p-toluenesulfonyl chloride 
• 58723-96-9 (Z)-1,2-dichloro-2-phenylethylene 
• 1483-82-5 phenylethynyl chloride 
• 591-50-4 iodobenzene 
• 100-52-7 benzaldehyde 
• 698-88-4 (2,2-dichlorovinyl)benzene 

Relevant academic research and scientific papers

Synthesis of Sulfonamide-Based Ynamides and Ynamines in Water

Ynamides, though relatively more stable than ynamines, are still moisture-sensitive and prone to hydration especially under acidic and heating conditions. Here we report an environmentally benign, robust protocol to synthesize sulfonamide-based ynamides and arylynamines via Sonogashira coupling reactions in water, using a readily available quaternary ammonium salt as the surfactant.

Direct oxidation ofN-ynylsulfonamides intoN-sulfonyloxoacetamides with DMSO as a nucleophilic oxidant

N-Arylethynylsulfonamides are oxidized intoN-sulfonyl-2-aryloxoacetamides directly and efficiently with dimethyl sulfoxide (DMSO) as both an oxidant and solvent with microwave assistance. DFT calculations indicate that DMSO nucleophilically attacks the ethylic triple bond and transfers its oxygen atom to the triple bond to form zwitterionic anionicN-sulfonyliminiums to trigger the reaction. Then it nucleophilically attacks the generated iminium intermediates to accomplish the oxidationviathe second oxygen atom transfer. The current method provides a straightforward and efficient strategy to transform variousN-arylethynylsulfonamides intoN-sulfonyl-2-aryloxoacetamides, sulfonyl oxoacetimides, without any other electrophilic activators or oxidants.

TMSOTf-mediated approach to 1,3-oxazin-2-one skeleton through one-pot successive reduction-[4 + 2] cyclization process of imides with ynamides

A one-pot approach to access functionalized 1,3-oxazin-2-one skeleton has been developed through successive reduction and subsequent [4 + 2] cyclization process of N-Boc lactams with ynamides by TMSOTf. As a result, a number of five to seven membered ring fused bicyclic [1,2-c][1,3]oxazin-1-ones 12a-m and tricyclic derivatives 13a-f were obtained in moderate to excellent yields with excellent regioselectivities. Moreover, linear N-Boc amides 9a-e were also amenable to this transformation, and the desired 3,4-dihydro-1,3-oxazin-2-ones 14a-m were readily achieved in moderate yields with excellent regioselectivities.

Synthesis of dihydro-[1,3]oxazino[4,3-a] isoindole and tetrahydroisoquinoline through Cu(OTf)2-catalyzed reactions of N-acyliminium ions with ynamides

An efficient approach to access functionalized dihydro-[1,3]oxazino[4,3-a] isoindole and tetrahydroisoquinoline skeletons has been developed through the addition-cyclization process of ynamides 8 with N-acyliminium ions generated from N,O-acetals 6,7. The reactions were conducted under the catalysis of Cu(OTf)2, and a number of functionalized dihydro-[1,3]oxazino[4,3-a] isoindoles 9a-9y and tetrahydroisoquinolines 10a-10g, 11a-11p were generated in 48–98% yields. When chiral ynamides 8n-8u were used, optically pure products 11a-11p could be obtained with good to excellent yields and diastereoselectivities.

Chemo- And regioselective click reactions through nickel-catalyzed azide-alkyne cycloaddition

Metal-catalyzed cycloaddition is an expeditious synthetic route to functionalized heterocyclic frameworks. However, achieving reactivity-controlled metal-catalyzed azide-alkyne cycloadditions from competing internal alkynes has been challenging. Herein, we report a nickel-catalyzed [3 + 2] cycloaddition of unsymmetrical alkynes with organic azides to afford functionalized 1,2,3-triazoles with excellent regio- and chemoselectivity control. Terminal alkynes and cyanoalkynes afford 1,5-disubstituted triazoles and 1,4,5-trisubstituted triazoles bearing a 4-cyano substituent, respectively. Thioalkynes and ynamides exhibit inverse regioselectivity compared with terminal alkynes and cyanoalkynes, affording 1,4,5-trisubstituted triazoles with 5-thiol and 5-amide substituents, respectively. Density functional theory calculations are performed for the elucidation of the reaction mechanism. The computed mechanism suggests that a nickellacyclopropene intermediate is generated by the oxidative addition of the alkyne substrate to the Ni(0)-Xantphos catalyst, and the subsequent C-N coupling of this intermediate with an azide is responsible for the chemo- and regioselectivity.

Synthesis of Amide Enol Carbamates and Carbonates through Cu(OTf)2-Catalyzed Reactions of Ynamides with t-Butyl Carbamates/Carbonates

A highly regioselective approach to access amide enol carbamates and carbonates 5a-5c′, 7a-7h, and 9 was developed through Cu(OTf)2-catalyzed reactions of ynamides 4 with t-butyl carbamates 2 and 8 and t-butyl carbonates 6. Moreover, this strategy was successfully applied to generate amide enol carbamates 11a-11s and 14a-14f from imides 10 and 13 with ynamides through an N-Boc cleavage-addition ring-opening process. A range of substituents was amenable to this transformation, and the desired amide enol carbamates and carbonates were obtained in moderate to good yields.

Synthesis of a 3,4-Dihydro-1,3-oxazin-2-ones Skeleton via an Intermolecular [4 + 2] Process of N-Acyliminium Ions with Ynamides/Terminal Alkynes

An approach to access functionalized 3,4-dihydro-1,3-oxazin-2-ones has been developed by reacting semicyclic N,O-acetals 5 and 6 with ynamides 7 or terminal alkynes 8 in a one-pot fashion. The reaction went through a formal [4 + 2] cycloaddition process to generate a number of functionalized 3,4-dihydro-1,3-oxazin-2-ones 9a-9ak and 10a-10bc in yields of 34-97%. In addition, the utility of this transformation was demonstrated by the synthesis of (±)-sedamine 13.

Transition-Metal-Free One-Step Synthesis of Ynamides

A robust transition-metal-free one-step strategy for the synthesis of ynamides from sulfonamides and (Z)-1,2-dichloroalkenes or alkynyl chlorides is presented. This method is not only effective for internal ynamides but also amenable for terminal ynamides. Various functional groups, even the vinyl moiety, are compatible, and thus, this strategy offers the opportunity for further functionalization.

A Micellar Catalysis Strategy for Amidation of Alkynyl Bromides: Synthesis of Ynamides in Water

Copper-catalyzed amidation of alkynyl bromides can be carried out in water for the first time, which is made possible by a micellar catalysis strategy using rosin-based surfactant APGS-550-M. The surfactant can be easily prepared from natural abundant biomass, resin acids. Studies as to substrate scope and reaction aqueous medium recycling showcase the ease and sustainability of this technology.

Sulfilimines as Versatile Nitrene Transfer Reagents: Facile Access to Diverse Aza-Heterocycles

We herein report the unprecedented synthesis of diverse biologically important aza-heterocycles by employing sulfilimines as nitrene transfer reagents. This class of sulfur-based aza-ylides had not been successfully used for gold nitrene transfer before. This work contains an efficient generation of α-imino gold carbenes by N?S cleavage of sulfilimines. These gold carbenes undergo C?H insertion, cyclopropanation, and nucleophilic attack to form indoles (44 examples), 3-azabicyclo[3.1.0]hexan-2-imines (24 examples), and imidazoles (3 examples). Our study represents a unique gold-catalyzed reaction between alkynes and sulfur ylides, and also includes the first aza-heterocycle synthesis that proceeds by intermolecular nitrene transfer followed by cyclopropanation of the α-imino gold carbenes. Moreover, an unexpected synthesis of 4-acylquinolines (3 examples) from 2-acylphenyl sulfilimines and propargylic silyl ether derivatives by a 1,2-hydride shift onto the α-imino gold carbene and a subsequent Mukaiyama aldol cyclization was discovered.