28272-96-0Relevant articles and documents
Construction of 4-Isochromanones through Cu(OTf)2-Catalysed Sequential C=O and C–O Bond Formation
Xing, Siyang,Gu, Nan,Qin, Jiajing,Cui, Hong,Li, Yan,Wang, Kui,Tian, Dawei,Chen, Bo,Yu, Guo
, p. 926 - 931 (2018)
A new strategy for the facile and efficient synthesis of 4-isochromanones has been developed. The reaction involves a Cu(OTf)2-catalysed sequential reaction of epoxides carrying electron-deficient alkenes using the solvent DMSO as the oxidant.
Diastereoselective Synthesis of the ABCD Ring System of Rubriflordilactone B
Roth, Hudson G.,Nicewicz, David A.
supporting information, p. 48 - 51 (2021/11/09)
A novel nine-step diastereoselective route to the ABCD ring system of the natural product rubriflordilactone B is reported. Use of an α-substituted butenolide derived from maleic anhydride facilitated a 1,4-conjugate addition to provide a diene. The order in which a ringclosing metathesis and enolate oxidation were performed on this compound dictated the relative stereochemistry of the target. The final product exhibited anisotropic effects during roomerature NMR studies, requiring elevatederature experiments to confirm its identity.
Palladium-Catalyzed Tandem Hydrocarbonylative Lactamization and Cycloaddition Reaction for the Construction of Bridged Polycyclic Lactams
Xu, Pengcheng,Qian, Bo,Hu, Bin,Huang, Hanmin
supporting information, p. 147 - 151 (2022/01/04)
The intramolecular hydroaminocarbonylation of alkenes is a compelling tool to rapidly access lactam, a privileged motif ubiquitous in natural products, pharmaceuticals, and agrochemicals. However, selective carbonylation to bridged polycyclic lactams with a lactam nitrogen at a bridgehead position is less explored. We herein report a modular palladium-catalyzed approach to perform a tandem hydrocarbonylative lactamization/Diels-Alder cycloaddition reaction with 2-vinyl aryl aldimines, alkenes, and CO, which offers convenient access to furnish the bridged polycyclic lactams in high yields with high selectivities.
Liquid-phase oxidation of olefins with rare hydronium ion salt of dinuclear dioxido-vanadium(V) complexes and comparative catalytic studies with analogous copper complexes
Maurya, Abhishek,Haldar, Chanchal
, (2021/02/26)
Homogeneous liquid-phase oxidation of a number of aromatic and aliphatic olefins was examined using dinuclear anionic vanadium dioxido complexes [(VO2)2(salLH)]? (1) and [(VO2)2(NsalLH)]? (2) and dinuclear copper complexes [(CuCl)2(salLH)]? (3) and [(CuCl)2(NsalLH)]? (4) (reaction of carbohydrazide with salicylaldehyde and 4-diethylamino salicylaldehyde afforded Schiff-base ligands [salLH4] and [NsalLH4], respectively). Anionic vanadium and copper complexes 1, 2, 3, and 4 were isolated in the form of their hydronium ion salt, which is rare. The molecular structure of the hydronium ion salt of anionic dinuclear vanadium dioxido complex [(VO2)2(salLH)]? (1) was established through single-crystal X-ray analysis. The chemical and structural properties were studied using Fourier transform infrared (FT-IR), ultraviolet–visible (UV–Vis), 1H and 13C nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS), electron paramagnetic resonance (EPR) spectroscopy, and thermogravimetric analysis (TGA). In the presence of hydrogen peroxide, both dinuclear vanadium dioxido complexes were applied for the oxidation of a series of aromatic and aliphatic alkenes. High catalytic activity and efficiency were achieved using catalysts 1 and 2 in the oxidation of olefins. Alkenes with electron-donating groups make the oxidation processes easy. Thus, in general, aromatic olefins show better substrate conversion in comparison to the aliphatic olefins. Under optimized reaction conditions, both copper catalysts 3 and 4 fail to compete with the activity shown by their vanadium counterparts. Irrespective of olefins, metal (vanadium or copper) complexes of the ligand [salLH4] (I) show better substrate conversion(%) compared with the metal complexes of the ligand [NsalLH4] (II).
A Transient Directing Group Strategy Enables Enantioselective Multicomponent Organofluorine Synthesis
Liu, Zhonglin,Oxtoby, Lucas J.,Liu, Mingyu,Li, Zi-Qi,Tran, Van T.,Gao, Yang,Engle, Keary M.
, p. 8962 - 8969 (2021/07/01)
The vicinal fluorofunctionalization of alkenes represents an expedient strategy for converting feedstock olefins into valuable fluorinated molecules and as such has garnered significant attention from the synthetic community; however, current methods remain limited in terms of scope and selectivity. Here we report the site-selective palladium-catalyzed three-component coupling of alkenylbenzaldehydes, arylboronic acids, and N-fluoro-2,4,6-trimethylpyridinium hexafluorophosphate facilitated by a transient directing group. The synthetically enabling methodology constructs vicinal stereocenters with excellent regio-, diastereo-, and enantioselectivities, forging products that map onto bioactive compounds.
Enantioselective synthesis of 1-aminoindene derivativesviaasymmetric Br?nsted acid catalysis
Wu, Xiang,Ding, Du,Zhang, Ying,Jiang, Hua-Jie,Wang, Tao,Zhao, Li-Ping
, p. 9680 - 9683 (2021/09/30)
We describe a catalytic asymmetric iminium ion cyclization reaction of simple 2-alkenylbenzaldimines using a BINOL-derived chiralN-triflyl phosphoramide. The corresponding 1-aminoindenes and tetracyclic 1-aminoindanes are formed in good yields and high enantioselectivities. Further, the chemical utility of the obtained enantiopure 1-aminoindene is demonstrated for the asymmetric synthesis of (S)-rasagiline.
Copper(I)-Catalyzed Enyne Oxidation/Cyclopropanation: Divergent and Enantioselective Synthesis of Cyclopropanes
Shen, Wen-Bo,Tang, Xiang-Ting,Zhang, Ting-Ting,Lv, Dong-Can,Zhao, Dan,Su, Tong-Fu,Meng, Lei
supporting information, p. 1285 - 1290 (2021/02/20)
An efficient copper(I)-catalyzed enyne oxidation/cyclopropanation for the modular synthesis of cyclopropane derivatives is described, which represents the first non-noble metal-catalyzed enynes oxidation/cyclopropanation by the in situ generated α-oxo copper carbenes. This protocol allows the assembly of valuable cyclopropane-γ-lactams in generally good to excellent yields with excellent diastereoselectivity. More significantly, the enantioselective version of enyne oxidation/cyclopropanation has been disclosed with chiral copper catalysts.
Construction of Partially Protected Nonsymmetrical Biaryldiols via Semipinacol Rearrangement of o-NQM Derived from Enynones
Wu, Feng,Cheng, Tairan,Zhu, Shifa
supporting information, p. 71 - 75 (2021/01/09)
The construction of partially protected nonsymmetrical biaryldiols catalyzed by AgBF4 has been achieved. The approach facilitates the formation of two new aryl rings and the introduction of two hydroxyl groups (one free and one TBS-protected) via the o-NQM generation/semipinacol rearrangement cascade, featuring high atom- and step-economy to afford a diverse array of partially protected nonsymmetrical biaryldiols under mild conditions.
Tandem Reaction Approaches to Isoquinolones from 2-Vinylbenzaldehydes and Anilines via Imine Formation-6π-Electrocyclization-Aerobic Oxidation Sequence
Lee, Jiyeon,Kim, Hun Young,Oh, Kyungsoo
, p. 474 - 478 (2020/01/21)
Two distinctive transition-metal-promoted aerobic oxidation protocols have been developed for the synthesis of isoquinolones from 2-vinylbenzaldehydes and aniline derivatives. Thus, the one-pot tandem reaction sequence of imine formation, thermal 6π-electrocyclization, followed by either Cu(OAc)2-mediated or Pd(OAc)2-catalyzed aerobic oxidation protocol allowed the ready access to isoquinolone derivatives. The control experiments revealed that the 1,2-dihydroisoquinoline intermediates from the 6π-electrocyclization of 1-azatrienes were aerobically oxidized to isoquinolones in the presence of either Cu(OAc)2 or Pd(OAc)2 catalyst.
Carbonylative cycloaddition between two different alkenes enabled by reactive directing groups: Expedited construction of bridged polycyclic skeletons
Gao, Bingjian,Zou, Suchen,Yang, Guoqing,Ding, Yongzheng,Huang, Hanmin
supporting information, p. 12198 - 12201 (2020/10/26)
A novel palladium-catalyzed highly selective hydrocarbonylative cycloaddition reaction with two different alkenes in the presence of CO enabled by a reactive directing-group is developed, which offers efficient and convenient access to lactone-containing bridged polycyclic compounds in high yield with high chemo- and stereoselectivities.
