49710-70-5Relevant academic research and scientific papers
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.
Modular isoquinoline synthesis using catalytic enolate arylation and in situ functionalization
Pilgrim, Ben S.,Gatland, Alice E.,McTernan, Charlie T.,Procopiou, Panayiotis A.,Donohoe, Timothy J.
supporting information, p. 6190 - 6193 (2014/01/17)
A methyl ketone, an aryl bromide, an electrophile, and ammonium chloride were combined in a four-component, three-step, and one-pot coupling procedure to furnish substituted isoquinolines in overall yields of up to 80%. This protocol utilizes the palladiu
New fluorescent isoquinoline derivatives
Balog, József,Riedl, Zsuzsanna,Hajós, Gy?rgy,Miskolczy, Zsombor,Biczók, László
body text, p. 5264 - 5266 (2011/10/19)
Various structural modifications of 3-amino and 3-hydroxyisoquinolines have been carried out to provide new fluorescent derivatives. The transformations involved nucleophilic substitution of a bromine atom or a triflate moiety at positions 1 and 3, respectively, as well as the condensation reaction of a 3-amino group with triethyl orthoformate and subsequent transformation with amines to give amidines. The new compounds have been studied by fluorescence spectroscopy.
A new synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring. Observation of an unexpected Dimroth rearrangement
Filák, László,Riedl, Zsuzsanna,Egyed, Orsolya,Czugler, Mátyás,Hoang, Cuong N.,Schantl, Joachim G.,Hajós, Gy?rgy
, p. 1101 - 1113 (2008/09/17)
A new and general synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring system starting from 2,3-diaminoisoquinolinium salts has been elaborated. Starting compounds bearing an alkyl group in position 4 easily reacted with aldehydes to yield the cyclized products. In the case of a lack of electron donating group in position 4 (e.g., unsubstituted or 4-cyano substituted diamino derivatives) a Dimroth rearrangement took place under the same reaction conditions to yield 3-isoquinolylhydrazones. The mechanism of this unexpected transformation has been verified by isotope labelling experiments. Clarification of the reaction mechanism allowed finding proper reaction conditions to eliminate the rearrangement route, and thus, to perfect successful ring closure to the fused triazoles.
