2170-09-4Relevant articles and documents
Synthesis and structures of complexes with axially chiral isoquinolinyl-naphtholate ligands
Howard, Ruth H.,Alonso-Moreno, Carlos,Broomfield, Lewis M.,Hughes, David L.,Wright, Joseph A.,Bochmann, Manfred
, p. 8667 - 8682 (2009)
The synthesis of axially chiral ligands 1-(3′,6′-di-t-butyl- 2′-hydroxy-1′-naphthyl)-3-R-isoquinoline (R = H, Pri, But) (LR-H) is described. Ligands with unsubstituted isoquinolinyl rings tend to give 1:2 metal complexes. The syntheses and crystal structures of Li2(LH)2(THF)2 (9), (LH)2Ti(OPri)2 (12), Zn(L H)2 (13) and [Mg(LH)2]2 (14) are reported. Complex formation is highly stereoselective; the ligands in 1:2 complexes have the same stereochemistry (i.e. R,R and S,S but not R,S), whereas in the binuclear magnesium compound 14 the bridging and non-bridging ligands LH have opposite stereochemistry. The reaction of L H-H with Pd(acac)2 afforded the N,O chelate Pd(acac)(LH) (10), whereas towards K2PtCl4 the same ligand acts as an N-donor only, to give trans-PtCl2(L H-H)2 (11) in which the OH groups are hydrogen-bonded to one of the two chloride ligands. The more bulky ligand with a t-butyl substituent in the 3-position of the isoquinolinyl ring reacts with zinc and magnesium bis(amides) to give the mixed-ligand species (LBu) ZnN(SiMe3)2 and (LBu)MgN(SiMe3) 2, respectively, which catalyse the ring-opening polymerisation of ε-caprolactone (CL) and rac-lactide (LA).
Trifluoroacetic Acid Hydroxylamine System as Organocatalyst Reagent in a One-Pot Salt Free Process for the Synthesis of Caprolactam and Amides of Industrial Interest
Manente,Pietrobon,Ronchin,Vavasori
, p. 3543 - 3549 (2021/03/30)
In this work we studied the reactivity of the Trifluoroacetic acid hydroxylamine system in the one step salt free synthesis of amides from ketones. A particular regards was paid to the caprolactam synthesis because of its industrial relevance. Synthesis, reactivity and characterization of the hydroxylamine trifluoroacetate is given. Fast oximation reaction of several ketones was gained at room temperature (1?h of reaction quantitative conversion for several ketones). In the same reactor, by raising the temperature at 383?K, the Beckmann rearrangement of the so obtained oximes is easily accomplished in the presence of three equivalent of TFA. The possibility of obtaining the trifluoroacetate of the hydroxylamine with a modified nitric acid hydrogenation reactions was verified, too. Reuse of solvent and trifluoroacetic acid is easily achieved by distillation. Graphical abstract: Salt free one-pot caprolactam and amides process catalyzed by CF3COOH, in the presence of NH2OH TFA as the oximation agent.[Figure not available: see fulltext.].
Assemblies of 1,4-Bis(diarylamino)naphthalenes and Aromatic Amphiphiles: Highly Reducing Photoredox Catalysis in Water
Abe, Manabu,Akita, Munetaka,Chitose, Youhei,Hyodo, Yuki,Koike, Takashi,Takahashi, Keigo,Yoshizawa, Michito
supporting information, (2021/10/21)
Host-guest assemblies of a designed 1,4-bis(diarylamino)naphthalene and V-shaped aromatic amphiphiles consisting of two pentamethylbenzene moieties bridged by an m -phenylene unit bearing two hydrophilic side chains emerged as highly reducing photoredox catalysis systems in water. An efficient demethoxylative hydrogen transfer of Weinreb amides has been developed. The present supramolecular strategy permits facile tuning of visible-light photoredox catalysis in water.
OPTIONALLY NITROGENATED ISOQUINOLIN-1(2H)-ONES AND 1H-ISOCHROMEN- 1-ONES FOR TREATING PAIN AND PAIN RELATED CONDITIONS
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Page/Page column 62, (2020/05/29)
The present invention relates to new compounds that show pharmacological activity towards the subunit α28 of voltage-gated calcium channels (VGCC), especially the α28 1 subunit of voltage-gated calcium channels or dual activity towards the subunit α28 of voltage-gated calcium channels (VGCC), especially the α28-1 subunit of voltage-gated calcium channels, and the μ-opiod receptor (MOR or mu-opioid). The invention is also related to the process for the preparation of said compounds as well as to compositions comprising them, and to their use as medicaments.
Dealkoxylation ofN-alkoxyamides without an external reductant driven by Pd/Al cooperative catalysis
Suzuki, Hirotsugu,Shiomi, Takahiro,Yoneoka, Kenji,Matsuda, Takanori
supporting information, p. 7545 - 7548 (2020/10/15)
Lewis acid-assisted palladium-catalysed dealkoxylation ofN-alkoxyamides has been developed. This reaction proceeded smoothly with a range ofN-alkoxyamides in the absence of an external reductant, thereby establishing a convenient and reductant-free protocol. In addition, a gram-scale reaction could be achieved. Preliminary mechanistic investigations indicated that β-hydrogen elimination from a palladium alkoxide intermediate generated an intramolecular hydride source.
Cobalt-catalysed C–H methylation for late-stage drug diversification
Ackermann, Lutz,Friis, Stig D.,Johansson, Magnus J.
, p. 511 - 519 (2020/06/05)
The magic methyl effect is well acknowledged in medicinal chemistry, but despite its significance, accessing such analogues via derivatization at a late stage remains a pivotal challenge. In an effort to mitigate this major limitation, we here present a strategy for the cobalt-catalysed late-stage C–H methylation of structurally complex drug molecules. Enabling broad applicability, the transformation relies on a boron-based methyl source and takes advantage of inherently present functional groups to guide the C–H activation. The relative reactivity observed for distinct classes of functionalities were determined and the sensitivity of the transformation towards a panel of common functional motifs was tested under various reaction conditions. Without the need for prefunctionalization or postdeprotection, a diverse array of marketed drug molecules and natural products could be methylated in a predictable manner. Subsequent physicochemical and biological testing confirmed the magnitude with which this seemingly minor structural change can affect important drug properties. [Figure not available: see fulltext.]
Iridium-catalyzed, ligand-controlled directed alkynylation and alkenylation of arenes with terminal alkynes
Sun, Xin,Zhao, Wei,Li, Bi-Jie
supporting information, p. 1298 - 1301 (2020/02/04)
We report iridium-catalyzed C-C formation between benzamides and terminal alkynes. With the choice of a suitable ligand, a C-H alkynylation or alkenylation product could be obtained selectively. The directed C-H alkynylation proceeded without the need for an external oxidant, while the directed C-H alkenylation likely involves an unusual vinylidene mechanism. This divergent reactivity provides access to both alkynylation and alkenylation products from the same set of starting materials.
Rhodium-Catalyzed Electrooxidative C?H Olefination of Benzamides
Ackermann, Lutz,Struwe, Julia,Zhang, Yan
supporting information, p. 15076 - 15080 (2020/06/20)
Metal-catalyzed chelation-assisted C?H olefinations have emerged as powerful tools for the construction of functionalized alkenes. Herein, we describe the rhoda-electrocatalyzed C?H activation/alkenylation of arenes. The olefinations of challenging electron-poor benzamides were thus accomplished in a fully dehydrogenative fashion under electrochemical conditions, avoiding stoichiometric chemical oxidants, and with H2 as the only byproduct. This versatile alkenylation reaction also features broad substrate scope and used electricity as a green oxidant.
Rhenium-Catalyzed Phthalide Synthesis from Benzamides and Aldehydes via C-H Bond Activation
Jia, Bing,Yang, Yunhui,Jin, Xiqing,Mao, Guoliang,Wang, Congyang
supporting information, p. 6259 - 6263 (2019/09/06)
The [4 + 1] annulation of benzamides and aldehydes for phthalide synthesis was achieved via rhenium-catalyzed C-H activation, which demonstrates an unprecedented reaction pattern distinct from those of other transition-metal catalyses. The reaction also features readily available starting materials, a wide scope for both electro-rich and electro-deficient substrates, and the elimination of homoannulation byproducts.
Hydrogen Bond Directed ortho-Selective C?H Borylation of Secondary Aromatic Amides
Bai, Shao-Tao,Bheeter, Charles B.,Reek, Joost N. H.
supporting information, p. 13039 - 13043 (2019/07/31)
Reported is an iridium catalyst for ortho-selective C?H borylation of challenging secondary aromatic amide substrates, and the regioselectivity is controlled by hydrogen-bond interactions. The BAIPy-Ir catalyst forms three hydrogen bonds with the substrate during the crucial activation step, and allows ortho-C?H borylation with high selectivity. The catalyst displays unprecedented ortho selectivities for a wide variety of substrates that differ in electronic and steric properties, and the catalyst tolerates various functional groups. The regioselective C?H borylation catalyst is readily accessible and converts substrates on gram scale with high selectivity and conversion.
