51089-62-4Relevant academic research and scientific papers
Highly Regioselective Isoquinoline Synthesis via Nickel-Catalyzed Iminoannulation of Alkynes at Room Temperature
Sun, Jian-Guo,Zhang, Xiao-Yu,Yang, Hua,Li, Ping,Zhang, Bo
, p. 4965 - 4969 (2018/09/25)
A simple and cost-efficient nickel catalytic system for the annulation of 2-haloaldimines with alkynes to synthesize 3,4-disubstituted and 3-substituted isoquinolines at room temperature has been developed. The air-stable and inexpensive Ni(dppe)Cl2 was employed as a precatalyst, and Et3N was found to be an essential additive for obtaining high yields. By using this nickel catalytic system one-pot three-component direct synthesis of isoquinolines starting with simple 2-halobenzaldehydes, tert-butylamine, and alkynes were also achieved. These reactions occur in moderate to excellent yields with complete regioselectivity. Moreover, these reactions feature a broad substrate scope, easy scalability, operational simplicity, and excellent practicality.
Cobalt-Catalyzed ortho-C?H Functionalization/Alkyne Annulation of Benzylamine Derivatives: Access to Dihydroisoquinolines
Martínez, ángel Manu,Rodríguez, Nuria,Gómez-Arrayás, Ramón,Carretero, Juan C.
, p. 11669 - 11676 (2017/08/30)
A practical picolinamide-directed C?H functionalization/alkyne annulation of benzylamine derivatives enabling access to the previously elusive 1,4-dihydroisoquinoline skeleton was developed using molecular O2 as the sole oxidant and Co(OAc)2 as precatalyst. The method is compatible with both internal and terminal alkynes and shows high versatility and functional-group tolerance. Furthermore, full preservation of enantiopurity is observed when using non-racemic α-substituted benzylamine derivatives. Kinetic analysis of the reagents and catalyst, labeling experiments, and the isolation and identification of catalytically competent Co-complexes revealed important insights about the mechanism.
Palladium-catalyzed enolate arylation as a key C-C bond-forming reaction for the synthesis of isoquinolines
Pilgrim, Ben S.,Gatland, Alice E.,Esteves, Carlos H. A.,McTernan, Charlie T.,Jones, Geraint R.,Tatton, Matthew R.,Procopiou, Panayiotis A.,Donohoe, Timothy J.
, p. 1065 - 1090 (2016/01/15)
The palladium-catalyzed coupling of an enolate with an ortho-functionalized aryl halide (an α-arylation) furnishes a protected 1,5-dicarbonyl moiety that can be cyclized to an isoquinoline with a source of ammonia. This fully regioselective synthetic route tolerates a wide range of substituents, including those that give rise to the traditionally difficult to access electron-deficient isoquinoline skeletons. These two synthetic operations can be combined to give a three-component, one-pot isoquinoline synthesis. Alternatively, cyclization of the intermediates with hydroxylamine hydrochloride engenders direct access to isoquinoline N-oxides; and cyclization with methylamine, gives isoquinolinium salts. Significant diversity is available in the substituents at the C4 position in four-component, one-pot couplings, by either trapping the in situ intermediate after α-arylation with carbon or heteroatom-based electrophiles, or by performing an α,α-heterodiarylation to install aryl groups at this position. The α-arylation of nitrile and ester enolates gives access to 3-amino and 3-hydroxyisoquinolines and the α-arylation of tert-butyl cyanoacetate followed by electrophile trapping, decarboxylation and cyclization, C4-functionalized 3-aminoisoquinolines. An oxime directing group can be used to direct a C-H functionalization/bromination, which allows monofunctionalized rather than difunctionalized aryl precursors to be brought through this synthetic route.
Palladium-catalyzed annulation of internal alkynes in aqueous medium
Ang, Wei Jie,Tai, Chih-Hsuan,Lo, Lee-Chiang,Lam, Yulin
, p. 4921 - 4929 (2014/01/23)
To facilitate precatalyst recovery and reuse, we have developed a fluorous, oxime-based palladacycle 1 and demonstrated that it is a very efficient and versatile precatalyst for carbo- and heteroannulation of internal alkynes with functionalized aryl halides in aqueous medium. A uniform reaction condition for these annulation reactions was also developed.
METHODS FOR PREPARING ISOQUINOLINES
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, (2013/03/26)
Provided herein are novel synthetic methods of making isoquinolines comprising coupling a metalated N-(2-methylbenzylidene)amine with a nitrile, followed by cyclization, to provide a substituted isoquinoline compound. This new methodology for preparing is
Synthesis of substituted isoquinolines utilizing palladium-catalyzed α-arylation of ketones
Donohoe, Timothy J.,Pilgrim, Ben S.,Jones, Geraint R.,Bassuto, Jose A.
, p. 11605 - 11608 (2012/09/07)
The utilization of sequential palladium-catalyzed α-arylation and cyclization reactions provides a general approach to an array of isoquinolines and their corresponding N-oxides. This methodology allows the convergent combination of readily available precursors in a regioselective manner and in excellent overall yields. This powerful route to polysubstituted isoquinolines, which is not limited to electron rich moieties, also allows rapid access to analogues of biologically active compounds.
A versatile synthesis of substituted isoquinolines
Si, Chong,Myers, Andrew G.
, p. 10409 - 10413 (2011/12/03)
Lithiated o-tolualdehyde tert-butylimines were shown to condense with nitriles to form eneamido anion intermediates that were trapped in situ with various electrophiles, thus affording a diverse array of highly substituted isoquinolines, many of which are
Facile synthesis of isoquinolines by imination and subsequent palladacycle-catalyzed iminoannulation of internal alkynes
Yang, Fan,Zhang, Junli,Wu, Yangjie
experimental part, p. 2969 - 2973 (2011/05/02)
An efficient and facile synthesis of isoquinolines has been described via a tandem reaction of imination of o-halobenzaldehydes with tert-butyl amine and subsequent palladacycle-catalyzed iminoannulation of internal alkynes. This tandem reaction could be carried out successively in one pot without any special operation, and the annulation step could afford isoquinolines derivatives in moderate to good yields with high regioselectivity. In addition, the simple synthesis of indoles was realized by palladacycle-catalyzed annulation of o-iodoaniline or o-bromoanilines with internal alkynes.
Synthesis of isoquinolines and pyridines by the palladium-catalyzed iminoannulation of internal alkynes
Roesch, Kevin R.,Zhang, Haiming,Larock, Richard C.
, p. 8042 - 8051 (2007/10/03)
A wide variety of substituted isoquinoline, tetrahydroisoquinoline, 5,6-dihydrobenz[f]isoquinoline, pyrindine, and pyridine heterocycles have been prepared in good to excellent yields via annulation of internal acetylenes with the tert-butylimines of o-iodobenzaldehydes and 3-halo-2-alkenals in the presence of a palladium catalyst. The best results are obtained by employing 5 mol % of Pd(OAc)2, an excess of the alkyne, 1 equiv of Na2CO3 as a base, and 10 mol % of PPh3 in DMF as the solvent. This annulation methodology is particularly effective for aryl- or alkenyl-substituted alkynes. When electron-rich imines are employed, this chemistry can be extended to alkyl-substituted alkynes. Trimethylsilyl-substituted alkynes also undergo this annulation process to afford monosubstituted heterocyclic products absent the silyl group.
Pyridine ring formation through the photoreaction of arenecarbothioamides with diene-conjugated carbonyl compounds
Oda, Kazuaki,Nakagami, Rikiji,Nishizono, Naozumi,Machida, Minoru
, p. 2371 - 2372 (2007/10/03)
Irradiation of arenecarbothioamides with hexa-2,4-dienal in benzene solution gives 2-arylpyridines in moderate yields.
