One of the major reasons for studying chemical kinetics is to use measurements of the macroscopic properties of a system, Recommanded Product: 497-25-6, such as the rate of change in the concentration of reactants or products with time.In a article, mentioned the application of 497-25-6, Name is Oxazolidin-2-one, molecular formula is C3H5NO2
Understanding the mechanism of procedure-controlled enantioselectivity switch in cinchona alkaloid thiourea catalyzed [3+2] cycloaddition: H-bonds controlled enantioselectivity
Density functional theory has been applied to the novel procedure-controlled enantioselectivity switch in the synthesis of chiral 2-oxazolidinone (3) through [3+2] cycloaddition between gamma-hydroxy-alpha,beta-unsaturated carbonyl compound (1) and isocyanate (2) catalyzed by a cinchona-alkaloid based aminothiourea catalyst. The study shows that three stages are involved in the whole process. In stage one, for Procedure A, 1 reacts with 2 to give carbamate intermediate. Then catalyst 4 is added. For Procedure B, catalyst 4 first activates 2 via quinuclidine N attacking isocyanate C. Then 1 is involved. In stage two, hydrogen is transferred from carbamate N to Ts O atom which is different from the quinuclidine N protonation mechanism. The last step is ring closure in which carbamate N attacks C atom of CC bond. From free energy profiles, the enantioselectivities of the reaction are determined by stage two. Further analysis shows that H-bond is the key in the procedure-controlled enantioselectivity switch. Different H-bonds (NAHA?OAC and NBHB?OAC in Procedure A vs NAHA?OAC and NBHB?OBS in Procedure B) lead to different relationships between thiourea and carbamate planes (vertical or parallel). In Procedure A, CC listing above carbamate plane is the favorable pathway to give R-3. However, in Procedure B, CC listing behind carbamate plane is more favorable to generate S-3.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. Recommanded Product: 497-25-6, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 497-25-6, in my other articles.
Reference£º
Oxazolidine – Wikipedia,
Oxazolidine | C3H603NO – PubChem