37614-57-6Relevant academic research and scientific papers
One-pot synthesis of 3-substituted-4H-[1,2,3] triazolo[5,1-c][1,4]oxazin-6(7H)-ones from propargyl alcohols, chloroacetyl chloride, and sodium azide
Chen, Jun-Min,Liu, Xiao-Ling,Sheng, Shou-Ri,Wei, Mei-Hong,Zhang, Xiao-Lan
, p. 482 - 485 (2020/11/30)
An efficient, one-pot synthesis of 3-substituted-4H-[1,2,3]triazolo[5,1-c][1,4]oxazin-6(7H)-ones is developed via sequential esterification, substitution, and 1,3-dipolar cycloaddition processes of various propargyl alcohols, chloroacetyl chloride, and so
Copper-Free Solid-Phase Synthesis of Triazolo[1,5-a][1,4]diazepin-6-ones
Kriegelsteinová, Patricia,Lemrová, Barbora,Ru?ilová, Veronika,Soural, Miroslav
, p. 1112 - 1119 (2021/01/04)
Synthesis of triazolo[1,5-a][1,4]diazepin-6-ones on solid support is reported in this article. Amino acids immobilized on Wang resin were nosylated and alkylated with propargyl alcohol, but-2-yn-1-ol or different 3-phenylprop-2-yn-1-ols using Mitsunobu alkylation conditions. After denosylation, acylation with Fmoc-azidoalanine yielded linear precursors that were thermally cyclized on resin to give immobilized triazolodiazepinones. After cleavage from the polymer support, the target compounds were obtained in high crude purities and good overall yields. Furthermore, the synthetic approach was applied to convenient solid-phase synthesis of oligopeptide containing the triazolodiazepinone moiety as the peptidomimetic heterocyclic constraint. (Figure presented.).
Copper-Catalyzed Cross-Nucleophile Coupling of β-Allenyl Silanes with Tertiary C-H Bonds: A Radical Approach to Branched 1,3-Dienes
Shan, Qi-Chao,Hu, Lu-Min,Qin, Wei,Hu, Xu-Hong
supporting information, p. 6041 - 6045 (2021/08/03)
Described herein is a distinctive approach to branched 1,3-dienes through oxidative coupling of two nucleophilic substrates, β-allenyl silanes, and hydrocarbons appending latent functionality by copper catalysis. Notably, C(sp3)-H dienylation proceeded in a regiospecific manner, even in the presence of competitive C-H bonds that are capable of occurring hydrogen atom transfer process, such as those located at benzylic and other tertiary sites, or adjacent to an oxygen atom. Control experiments support the intermediacy of functionalized alkyl radicals.
Copper(I)-Catalyzed Intramolecular Cyclization of o-Propargyloxy Diketopiperazines to Access Diverse Diazabicyclic and Spiro-Diketopiperazinochromanes
Armaghan, Mahsa,Balalaie, Saeed,Bijanzadeh, Hamid Reza,Frank, Walter,Manavi, Bita,Rominger, Frank,Tejeneki, Hossein Zahedian
supporting information, p. 4190 - 4196 (2021/08/06)
In this report, two distinctive intramolecular cyclizations of o-propargyloxy diketopiperazines (achieved from a one-pot Ugi post-transformation) is achieved via a copper(I)-catalyzed intramolecular reaction of azomethine ylide and alkyne moiety. The presence of internal alkyne in the starting materials directed the reaction towards through [3+2]-cycloaddition, while terminal alkyne led to a spirocyclization reaction between azomethine ylide and terminal unsaturated C?C bond. This method offering an opportunity for the synthesis of challenging Diazabicyclics and Spiro-Diketopiperazinochromanes in high yields with exclusive diastereoselectivity. (Figure presented.).
Transition-metal-free and facile synthesis of 3-alkynylpyrrole-2,4-dicarboxylates from methylene isocyanides and propiolaldehyde
Chen, Xiaojuan,Fu, Liping,Huo, Xiaoli,Shao, Jiaan,Yu, Liya,Zeng, Linghui,Zhang, Chong,Zhang, Jiankang,Zhu, Huajian
supporting information, p. 16430 - 16433 (2021/10/01)
A transition-metal-free, facile and efficient method for the synthesis of 3-alkynylpyrrole-2,4-dicarboxylates from methylene isocyanides and propiolaldehyde with moderate to good yields has been developed. The direct transformation process and good tolerance of various substituents make it an alternative approach to previous protocols, and potential applications of these investigated compounds are expected with or without post-modifications.
Organocatalytic Regio- and Enantioselective N-Alkylation of Isoxazol-5-ones
Li, Pengfei,Liu, Meiwen,Qian, Chenxiao
supporting information, p. 6777 - 6780 (2021/12/31)
A chiral phosphoric acid catalyzed regio- and enantioselective reaction between 1-acylamino-3-arylprop-2-yn-1-ols and isoxazol-5-ones has been developed for the first time. With the established protocol, N-alkylation of isoxazol-5-ones was achieved, affording enantioenriched N,N-acetals in 74–99 % yield with 72–88 % ee.
Bi(OTf)3-catalyed One-pot Synthesis of α-Halo-β-amino Ketones and Acyl Aziridines from 3-Aryl Propargyl Alcohols
Zhang, Qinglin,Duan, Yongbin,Guo, Huifeng,Yang, Hong,Zhai, Jiulong,Li, Tiantian,Wang, Zhihai,Lu, Xiaolei,Wang, Yan,Yin, Yan
supporting information, p. 1832 - 1838 (2021/06/09)
A Bi(OTf)3-catalyed reaction of 3-aryl propargyl alcohols with sulfonamide and halogen source was firstly investigated, which provided a facile route for the synthesis of a large variety of α-halo-β-amino ketones. The key intermediates, β-amino
Chemoselective Hydroboration of Propargylic Alcohols and Amines Using a Manganese(II) Catalyst
Brzozowska, Aleksandra,Zubar, Viktoriia,Ganardi, Ruth-Christine,Rueping, Magnus
supporting information, p. 3765 - 3769 (2020/04/15)
The first manganese-catalyzed hydroboration of propargylic alcohols and amines as well as internal alkynes is reported. High regio- and stereoselectivity is achieved by applying 2 mol % of a manganese precatalyst based on the readily accessible bis(imino)pyridine ligand and MnCl2 as metal source. Propargylic alcohols and amines, as well as symmetric internal alkynes, were efficiently converted into the corresponding functionalized alkenes, which can serve as important and valuable intermediates for further synthetic applications such as cross-coupling reactions.
Photocatalyzed Diastereoselective Isomerization of Cinnamyl Chlorides to Cyclopropanes
Dykstra, Ryan,Gutierrez, Osvaldo,Martin, Robert T.,Tambar, Uttam K.,Troian-Gautier, Ludovic,Xu, Bin
supporting information, p. 6206 - 6215 (2020/04/27)
Endergonic isomerizations are thermodynamically unfavored processes that are difficult to realize under thermal conditions. We report a photocatalytic and diastereoselective isomerization of acyclic cinnamyl chlorides to strained cyclopropanes. Quantum mechanical calculations (uM06-2X and DLPNO), including TD-DFT calculations, and experimental studies provide evidence for the energy transfer from an iridium photocatalyst to the allylic chloride substrate followed by C-Cl homolytic cleavage. Subsequent Cla￠ radical migration forms a localized triplet 1,3-diradical intermediate that, after intersystem crossing, undergoes ring-closing to form the desired product. The mild reaction conditions are compatible with a broad range of functional groups to generate chlorocyclopropanes in high yields and diastereoselectivities. A more efficient process is developed by addition of a catalytic amount of a nickel complex, and we propose a novel role for this cocatalyst to recycle an allyl chloride byproduct generated in the course of the reaction. The reaction is also shown to be stereoconvergent, as an E/Z mixture of cinnamyl chlorides furnish the anti-chlorocyclopropane product in high diastereoselectivity. We anticipate that the use of a visible light activated photocatalyst to transform substrates in combination with a transition metal catalyst to recycle byproducts back into the catalytic cycle will provide unique opportunities for the discovery of new reactivity.
Atom-Economical Ni-Catalyzed Diborylative Cyclization of Enynes: Preparation of Unsymmetrical Diboronates
Cabrera-Lobera, Natalia,Quirós, M. Teresa,Brennessel, William W.,Neidig, Michael L.,Bu?uel, Elena,Cárdenas, Diego J.
supporting information, p. 6552 - 6556 (2019/08/20)
We report a Ni-catalyzed diborylative cyclization of enynes that affords carbo- and heterocycles containing both alkyl- and alkenylboronates. The reaction is fully atom-economical, shows a broad scope, and employs a powerful and inexpensive catalytic Ni-b
