78168-74-8Relevant articles and documents
An Enzymatic Platform for Primary Amination of 1-Aryl-2-alkyl Alkynes
Liu, Zhen,Qin, Zi-Yang,Zhu, Ledong,Athavale, Soumitra V.,Sengupta, Arkajyoti,Jia, Zhi-Jun,Garcia-Borràs, Marc,Houk,Arnold, Frances H.
supporting information, p. 80 - 85 (2022/01/08)
Propargyl amines are versatile synthetic intermediates with numerous applications in the pharmaceutical industry. An attractive strategy for efficient preparation of these compounds is nitrene propargylic C(sp3)-H insertion. However, achieving this reacti
Atom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes
Liu, Mingyu,Tang, Tianhua,Apolinar, Omar,Matsuura, Rei,Busacca, Carl A.,Qu, Bo,Fandrick, Daniel R.,Zatolochnaya, Olga V.,Senanayake, Chris H.,Song, Jinhua J.,Engle, Keary M.
supporting information, p. 3881 - 3888 (2021/04/06)
Selective carbon-carbon (C-C) bond formation in chemical synthesis generally requires prefunctionalized building blocks. However, the requisite prefunctionalization steps undermine the overall efficiency of synthetic sequences that rely on such reactions, which is particularly problematic in large-scale applications, such as in the commercial production of pharmaceuticals. Herein, we describe a selective and catalytic method for synthesizing 1,3-enynes without prefunctionalized building blocks. In this transformation several classes of unactivated internal acceptor alkynes can be coupled with terminal donor alkynes to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcohols, (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. This method is facilitated by a tailored P,N-ligand that enables regioselective addition and suppresses secondary E/Z-isomerization of the product. The reaction is scalable and can operate effectively with as low as 0.5 mol % catalyst loading. The products are versatile intermediates that can participate in various downstream transformations. We also present preliminary mechanistic experiments that are consistent with a redox-neutral Pd(II) catalytic cycle.
Synthesis of 3-Keto Pyridines from the Conjugated Allenone – Alkynylamine Oxidative Cyclization Catalyzed by Supported Au Nanoparticles
Fragkiadakis, Michael,Kidonakis, Marios,Stratakis, Manolis,Zorba, Leandros
supporting information, p. 964 - 968 (2020/01/28)
Recyclable supported Au nanoparticles on TiO2 catalyze the cyclization of N-propargyl or N-homopropargyl β-enaminones followed by dehydrogenation (aromatization) leading to substituted 3-keto pyridines or 4-picolines in very good yields. This pathway is in contrast to their known cyclization in the presence of Au(I) or Au(III) catalysts which provides 1,4-oxazepines, instead. The enaminones are formed in situ upon mixing a conjugated allenone or allenyl ester with the alkynylamine, thus the pyridine-forming transformation is typically a one pot process. (Figure presented.).
