3947-78-2Relevant academic research and scientific papers
Visible-Light-Induced Controlled Oxidation of N-Substituted 1,2,3,4-Tetrahydroisoquinolines for the Synthesis of 3,4-Dihydroisoquinolin-1(2H)-ones and Isoquinolin-1(2H)-ones
Bansode, Ajay H.,Suryavanshi, Gurunath
supporting information, p. 1390 - 1400 (2021/01/26)
A visible light-rose bengal-TBHP mediated, controlled oxidation of N-substituted 1,2,3,4-tetrahydroisoquinolines is developed for the synthesis of 3,4-dihydroisoquinolin-1(2H)-ones and isoquinolin-1(2H)-ones. The present method feature's a broad substrate scope, good functional group tolerances, and the products were prepared in good to excellent yields. The developed methodology further demonstrated in the synthesis of isoindolo[2,1-b] isoquinolin-5(7H)-one (topoisomerase-I inhibitor). (Figure presented.).
Metal-Free Activation of C(sp3)–H Bond, and a Practical and Rapid Synthesis of Privileged 1-Substituted 1,2,3,4-Tetrahydroisoquinolines
Choudhury, Santosh Kumar,Rout, Pragati,Parida, Bibhuti Bhusan,Florent, Jean-Claude,Johannes, Ludger,Phaomei, Ganngam,Bertounesque, Emmanuel,Rout, Laxmidhar
, p. 5275 - 5292 (2017/09/29)
The reaction of cotarnine and acyl/aryl ketones in “green” solvents provides an efficient approach to an array of privileged 1,2,3,4-tetrahydroisoquinolines in excellent yields by metal-free activation of C(sp3)–H bonds. This one-pot procedure takes place under base-free conditions at room temperature, and tolerates a wide range of functionalities. The reaction is highly chemoselective, can be performed on a multi-gram scale, and pure products are isolated by simple filtration without workup. Interestingly, the complementary two-step procedure from cotarnine halide salts gives the Mannich products in good yields. The scope was elaborated to 9-bromocotarnine salts to access a range of 9-bromonoscapine-derived analogues. The methodology has been developed considering the structural similarity of cotarnine derivatives to noscapinoids, which represent an emerging class of microtubule-modulating anticancer agents.
Catalytic bio-chemo and bio-bio tandem oxidation reactions for amide and carboxylic acid synthesis
Bechi, Beatrice,Herter, Susanne,McKenna, Shane,Riley, Christopher,Leimkühler, Silke,Turner, Nicholas J.,Carnell, Andrew J.
supporting information, p. 4524 - 4529 (2014/12/11)
A catalytic toolbox for three different water-based one-pot cascades to convert aryl alcohols to amides and acids and cyclic amines to lactams, involving combination of oxidative enzymes (monoamine oxidase, xanthine dehydrogenase, galactose oxidase and laccase) and chemical oxidants (TBHP or CuI(cat)/H2O2) at mild temperatures, is presented. Mutually compatible conditions were found to afford products in good to excellent yields. This journal is
Alkali metal-mediated synthesis of 1- and 4-substituted N-alkyl-1,2,3,4-tetrahydroisoquinolines
Azzena, Ugo,Pisano, Luisa,Pittalis, Mario
, p. 401 - 409 (2007/10/03)
Reductive cleavage by electron transfer from Li or K metal of 1-alkoxy-substituted N-alkyltetrahydroisoquinolines led to the formation of organometallic derivatives. Quenching of these intermediates with electrophilic reagents afforded 1- or 4-substituted
Kinetics of the Reduction of 3,4-Dihydroisoquinolinium Cations by 1,4-Dihydronicotinamides
Bunting, John W.,Chew, Vivian S. F.,Chu, Gary
, p. 2308 - 2312 (2007/10/02)
Pseudo-first-order rate constants for the reduction of 2-methyl-3,4-dihydroisoquinolinium cation (1) by 1-(X-benzyl)-1,4-dihydronicotinamides (3) display kinetic saturation at high concentrations of 1 (20percent CH3CN-80percent H2O, 25 deg C, ionic strength 1.0).Association constants for 1:1 complex formation are independent of X (1.4 +/- 0.2 M-1) and are most simply interpreted in terms of nonproductive complex formation.Pseudo-first-order rate constants for the reduction of 2-(Z-benzyl)-3,4-dihydroisoquinolinium cations (2) by 3 are linear for up to approximately 60 mM.Hammett correlations for the second-order rate constants for these reactions give ρx = -0.77 for the reduction of 2 (Z = 4-CN) by 3 and ρz = 0.83 for the reduction of 2 by 3 (X = H).Comparisons of ρx and ρz with equilibrium ρ values for closely related reactions indicate that the migrating hydrogen atom bears a charge of -0.33 and thus is clearly hydridic in character.These results are closely analogous to the conclusions of our earlier study of the 1,4-dihydronicotinamide reduction of 5-nitroisoquinolinium cations which have similar pKR+ values to those for 2.Thus similar reduction mechanisms apply to the reduction of aromatic and nonaromatic cations by 3. pKR+ values for pseudobase formation from 2 are correlated with a Hammett ρ = 1.72.The second-order rate constant for hydroxide ion attack on 2 (X = H) is fivefold larger than for the 2-benzyl-5-nitroisoquinolinium cation, although the second-order rate constant for reduction by 3 (X = H) is 23-fold greater for the latter cation than for 2 (X = H).This is interpreted in terms of a poorer "fit" between 2 and 3 in the transition state for the reduction, relative to the better "fit" between the planar 5-nitroisoquinolinium cations and 3.
