New Advances in Chemical Research in 2021. In homogeneous catalysis, the catalyst is in the same phase as the reactant. The number of collisions between reactants and catalyst is at a maximum.In a patent, 1612-65-3, name is 2-Methyl-1,2,3,4-tetrahydroisoquinoline, introducing its new discovery. Electric Literature of 1612-65-3
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 <2> up to approximately 60 mM.Hammett correlations for the second-order rate constants for these reactions give rhox = -0.77 for the reduction of 2 (Z = 4-CN) by 3 and rhoz = 0.83 for the reduction of 2 by 3 (X = H).Comparisons of rhox and rhoz with equilibrium rho 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 rho = 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.
The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 1612-65-3 is helpful to your research. Electric Literature of 1612-65-3
Reference：
Tetrahydroisoquinoline – Wikipedia,
1,2,3,4-Tetrahydroisoquinoline | C9H11N – PubChem