21167-85-1Relevant articles and documents
The reactions of O-(4-nitrophenyl) S-aryl dithiocarbonates with anilines: Effects on the relative nucleofugality
Santos, José G.,Gazitúa, Marcela
supporting information, (2019/01/03)
Kinetic and high-performance liquid chromatography studies were investigated for the reactions of S-phenyl, S-(4-chlorophenyl), and S-(4-nitrophenyl) O-(4-nitrophenyl) dithiocarbonates with anilines. These were performed in the presence of 0.1M borate buffer in 44?wt% aqueous ethanol. For reactions of the 3 substrates, the mechanism is stepwise with 2 tetrahedral intermediates, one zwitterionic (T±), and the other anionic (T?), where the intermediate T? is formed by proton transfer from T± to the borate buffer. The nonleaving group is not passive, playing an important role in the relative nucleofugality of the groups, which depend largely on its electron withdrawing capability. The nucleofugacity of 4-nitrophenolate ion and of 4-nitrophenylthiolate from the same tetrahedral intermediate is similar, despite the differences in their basicities (3 pKa units). In the reactions of S-(4-nitrophenyl) O-(4-nitrophenyl) dithiocarbonate, the change of nucleophile from pyridines (only 4-nitrophenolate ion is nucleofuge) to anilines (2 nucleofuges) shows that the nature of the amine impacts on the relative nucleofugality of groups.
Highly Active Dinuclear Titanium(IV) Complexes for the Catalytic Formation of a Carbon-Heteroatom Bond
Bhattacharjee, Jayeeta,Harinath, Adimulam,Banerjee, Indrani,Nayek, Hari Pada,Panda, Tarun K.
supporting information, p. 12610 - 12623 (2018/10/09)
A series of mononuclear titanium(IV) complexes with the general composition κ3-[R{NHPh2P(X)}2Ti(NMe2)2] [R = C6H4, X = Se (3b); R = trans-C6H10, X = S (4a), Se (4b)] and [{κ2-N(PPh2Se)2}2Ti(NMe2)2] (6b) and two dinuclear titanium(IV) complexes, [C6H4{(NPh2PS)(N)}Ti(NMe2)]2 (3c) and [{κ2-N(PPh2Se)}Ti(NMe2)2]2 (6c), are reported. Dinuclear titanium(IV) complex 6c acts as an efficient catalyst for the chemoselective addition of an E-H bond (E = N, O, S, P, C) to heterocumulenes under mild conditions. The catalytic addition of aliphatic and aromatic amines, alcohol, thiol, phosphine oxide, and acetylene to the carbodiimides afforded the corresponding hydroelemented products in high yield at mild conditions with a broader substrate scope. The catalytic efficiency of the dinuclear complex depends on the cooperative effect of the TiIV ions, the systematic variation of the intermetallic distance, and the ligand's steric properties of the complex, which enhances the reaction rate. Most interestingly, this is the first example of catalytic insertion of various E-H bonds into the carbodiimides using a single-site catalyst because only the titanium-mediated insertion of E-H into a C-N unsaturated bond is reported to date. The amine and alcohol insertion reaction with the carbodiimides showed first-order kinetics with respect to the titanium(IV) catalyst as well as substrates. A most plausible mechanism for hydroelementation reaction is also proposed, based on the spectroscopic data of the controlled reaction, a time-course study, and the Hammett plot.
HYDROLYSIS KINETICS AND MECHANISM OF DIARYLDITHIOCARBAMATES IN 20percent AQUEOUS DIOXANE
Mindl, Jaromir,Sulzer, Jiri,Vecera, Miroslav
, p. 1970 - 1975 (2007/10/02)
Nine diaryldithiocarbamates have been prepared.Kinetic study of their hydrolysis has revealed that this hydrolysis proceeds by ElcB mechanism in the pH range 2 to 12.Values of activation entropies, reaction constants, Broented coefficient, and comparison
