1160112-01-5Relevant academic research and scientific papers
Dual ligand-promoted palladium-catalyzed nondirected C-H alkenylation of aryl ethers
Fu, Manlin,Liu, Jiang,Wang, Lei,Yin, Biao,Zhu, Qing
, p. 3293 - 3296 (2020)
Direct C-H functionalization of aryl ethers remains challenging owing to their low reactivity and selectivity. Herein, a novel strategy for nondirected C-H alkenylation of aryl ethers promoted by a dual ligand catalyst was demonstrated. This catalytic system readily achieved the highly efficient alkenylation of alkyl aryl ethers (anisole, phenetole, n-propyl phenyl ether, n-butyl phenyl ether and benzyl phenyl ether), cyclic aryl ethers (1,4-benzodioxan, 2,3-dihydrobenzofuran, dibenzofuran), and diphenyl oxides. Moreover, the proposed methodology was successfully employed for the late-stage modification of complex drugs containing the aryl ether motif. Interestingly, the compounds developed herein displayed fluorescent properties, which would facilitate their biological applications.
Olefin functionalization/isomerization enables stereoselective alkene synthesis
Gutierrez, Osvaldo,Koh, Ming Joo,Liu, Chen-Fei,Martin, Robert T.,Wang, Hongyu,Zhao, Haonan
, p. 674 - 683 (2021/08/06)
Despite tremendous efforts aimed at devising methods for stereoselective alkene synthesis, critical challenges are yet to be addressed. Direct access to a diverse range of 1-aryl(boryl)-1-methyl-functionalized tri- and tetrasubstituted trans alkenes, entities that are prevalent in many important molecules, through a catalytic manifold from readily available α-olefin substrates remains elusive. Here, we demonstrate that catalytic amounts of a non-precious N-heterocyclic carbene–Ni(I) complex in conjunction with a sterically bulky base promote site- and trans-selective union of monosubstituted olefins with a wide array of electrophilic reagents to deliver tri- and tetrasubstituted alkenes in up to 92% yield and >98% regio- and stereoselectivity. The protocol is amenable to the preparation of carbon- and heteroatom-substituted C=C bonds, providing distinct advantages over existing transformations. Utility is highlighted through concise stereoselective synthesis of biologically active compounds. [Figure not available: see fulltext.].
Carbonyl–Olefin Cross-Metathesis Through a Visible-Light-Induced 1,3-Diol Formation and Fragmentation Sequence
Pitzer, Lena,Sandfort, Frederik,Strieth-Kalthoff, Felix,Glorius, Frank
, p. 16219 - 16223 (2018/11/23)
A visible-light-mediated approach to carbonyl–olefin cross-metathesis is described. Photoinduced hole catalysis was used to promote the formation of 1,3-diols from aldehydes and styrenes, which were then readily fragmented under acidic conditions to form the cross-metathesis products. The use of 1,3-diols as intermediates, rather than the energetically more demanding oxetanes, provides a new, orthogonal mechanistic strategy for carbonyl–olefin cross-metathesis. Furthermore, this approach does not require any metals, ligands, or additives, and provides the products with high levels of E selectivity. A mechanistic rationale is provided and supported by both theoretical calculations and experiments. Additionally, a practical synthesis of a new acridinium-based photocatalyst, including full characterization, is presented.
Cobalt-catalyzed arylzincation of alkynes
Murakami, Kei,Yorimitsu, Hideki,Oshima, Koichiro
experimental part, p. 2373 - 2375 (2009/12/01)
Cobalt(II) bromide catalyzes arylzincation of alkynes with arylzinc iodide·lithium chloride complexes in acetonitrile. The scope of the arylzincation is wide enough to use unfunctionalized alkynes, such as 6-dodecyne, as well as arylacetylenes. The inherent functional group compatibility of arylzinc reagents allows preparation of various functionalized styrene derivatives. The reaction is applicable to the efficient and stereoselective synthesis of a synthetic estrogen and its derivative.
