65032-46-4Relevant academic research and scientific papers
Diamine Synthesis via the Nitrogen-Directed Azidation of σ- And π-C-C Bonds
Nguyen, Tin V. T.,Wang, Ming-Ming,Waser, Jerome
supporting information, p. 11969 - 11975 (2021/08/24)
Diamines are essential building blocks for the synthesis of agrochemicals, drugs, and organic materials, yet their synthesis remains challenging, as both nitrogens need to be differentiated and diverse substitution patterns (1,2, 1,3, or 1,4) are required. We report herein a new strategy giving access to 1,2, 1,3, and 1,4 amido azides as orthogonally protected diamines based on the nitrogen-directed diazidation of alkenes, cyclopropanes, and cyclobutanes. Commercially available copper thiophene-2-carboxylate (CuTc, 2 mol %) as catalyst promoted the diazidation of both πand σ C-C bonds within 10 min in the presence of readily available oxidants and trimethylsilyl azide. Selective substitution of the formed α-amino azide by carbon nucleophiles (electron-rich aromatic, malonate, organosilicon, organoboron, organozinc, and organomagnesium compounds) was then achieved in a one-pot fashion, leading to the formation of 1,2-, 1,3-, and 1,4-diamines with the amino groups protected orthogonally as an amide/carbamate and an azide.
Diastereoselective Photoredox-Catalyzed [3 + 2] Cycloadditions of N-Sulfonyl Cyclopropylamines with Electron-Deficient Olefins
White, Dawn H.,Noble, Adam,Booker-Milburn, Kevin I.,Aggarwal, Varinder K.
supporting information, p. 3038 - 3042 (2021/05/04)
A highly diastereoselective, visible-light-induced [3 + 2] cycloaddition between N-sulfonyl cyclopropylamines and electron-deficient olefins is reported. The reactions proceed via the oxidation of a sulfonamide aza-anion by an organic photocatalyst to generate a nitrogen-centered radical. Strain-induced ring opening and intermolecular addition to the olefin generate an intermediate carbon-centered radical that is reduced to an anion prior to 5-exo cyclization. This enables a highly diastereoselective construction of trans-cyclopentanes possessing synthetically useful functional groups.
Cobalt-Catalyzed 1,4-Aryl Migration/Desulfonylation Cascade: Synthesis of α-Aryl Amides
Gillaizeau-Simonian, Nicolas,Barde, Etienne,Guérinot, Amandine,Cossy, Janine
supporting information, p. 4004 - 4008 (2021/02/11)
A cobalt-catalyzed 1,4-aryl migration/disulfonylation cascade applied to α-bromo N-sulfonyl amides was developed. The reaction was highly chemoselective, allowing the preparation of α-aryl amides possessing a variety of functional groups. The method was used as the key step to synthesize an alkaloid, (±)-deoxyeseroline. Mechanistic investigations suggest a radical process.
Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron-Rich Substrates
Doobary, Sayad,Sedikides, Alexi T.,Caldora, Henry P.,Poole, Darren L.,Lennox, Alastair J. J.
supporting information, p. 1155 - 1160 (2019/12/11)
Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and conformation. The oxidative difluorination of alkenes represents an important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their safety and scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products that are otherwise unattainable. Key to success is the electrochemical generation of a hypervalent iodine mediator using an “ex-cell” approach, which avoids oxidative substrate decomposition. The more sustainable conditions give good to excellent yields in up to decagram scales.
Oxidative Fluorination of Cyclopropylamides through Organic Photoredox Catalysis
Wang, Ming-Ming,Waser, Jér?me
supporting information, p. 16420 - 16424 (2020/07/30)
We report an oxidative ring-opening strategy to transform cyclopropylamides and cyclobutylamides into fluorinated imines. The imines can be isolated in their more stable hemiaminal form, with the fluorine atom installed selectively at the γ or δ position. Both inexpensive benzophenone with UVA light or organic and inorganic dyes with blue light could be used as photoredox catalysts to promote this process. Various fluorinated amines were then obtained by nucleophilic attack on the hemiaminals in one pot, giving access to a broad range of useful building blocks for medicinal chemistry.
1,3-Difunctionalization of Aminocyclopropanes via Dielectrophilic Intermediates
Wang, Ming-Ming,Waser, Jér?me
supporting information, p. 13880 - 13884 (2019/08/30)
We report an oxidative ring-opening strategy to transform acyl, sulfonyl or carbamate protected aminocyclopropanes into 1,3-dielectrophilic carbon intermediates bearing a halide atom (Br, I) and a N,O-acetal. Replacing the alkoxy group of the N,O-acetal can be achieved under acidic conditions through an elimination–addition pathway, while substitution of the halides by nucleophiles can be done under basic conditions through a SN2 pathway, generating a wide range of 1,3-difunctionalized propylamines. A proof of concept for asymmetric induction was realized using a chiral phosphoric acid (CPA) as catalyst, highlighting the potential of the method in enantioselective synthesis of important building blocks.
Gold-Catalyzed Cyclisation by 1,4-Dioxidation
Claus, Vanessa,Molinari, Lise,Büllmann, Simon,Thusek, Jean,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
supporting information, p. 9385 - 9389 (2019/04/30)
Amide-substituted diynes were cyclized in the presence of a cationic gold catalyst and an external nucleophile leading to 1-indenones and 1-iminoindenones. The electron-donating features of the nitrogen atom enable the formation of a reactive ketene iminium ion, which can be trapped by either diphenyl sulfoxide or anthranil as nucleophiles in a subsequent oxidation step, providing substituted inden-1-on-3-carboxamides.
Transition-Metal-Free One-Step Synthesis of Ynamides
Zeng, Xianzhu,Tu, Yongliang,Zhang, Zhenming,You, Changming,Wu, Jiao,Ye, Zhiying,Zhao, Junfeng
, p. 4458 - 4466 (2019/03/26)
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
Yang, Yunqin,Meng, Xiangtai,Zhu, Baolong,Jia, Ying,Cao, Xiaoji,Huang, Shenlin
supporting information, p. 1166 - 1169 (2019/01/04)
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.
Dehydrogenation of N-Heterocycles by Superoxide Ion Generated through Single-Electron Transfer
Huang, Yuan-Qiong,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
supporting information, p. 2065 - 2069 (2018/01/27)
Nitrogen-containing heteroarene motifs are found in numerous pharmaceuticals, natural products, and synthetic materials. Although several elegant methods for synthesis of these compounds through dehydrogenation of the corresponding saturated heterocycles have been reported, some of the methods are hampered by long reaction times, harsh conditions, and the need for catalysts that are not readily available. This work reports a novel method for dehydrogenation of N-heterocycles. Specifically, O2.? generated in situ acts as the oxidant for N-heterocycle substrates that are susceptible to oxidation through a hydrogen atom transfer mechanism. This method provides a general, green route to N-heteroarenes.
