Computational studies on the asymmetric induction in intramolecular 1,3-dipolar cycloaddition of (S)-5-phenyl-morpholin-2-one

Intramolecular Dipolar Cycloaddition Reactions of Azomethine Ylides

“…The results indicate that cycloaddition with the alkenyl substrate occurs via the S-shaped ylide 72 , whereas with the alkynyl substrate the W-shaped ylide 74 is favored. These conclusions were supported by computational studies, in which the lowest energy transition states arise from these ylide geometries . Interestingly, cycloaddition with the substrate 6-heptynal, in which there is one extra methylene unit in the linking chain, resulted in a single product derived from the usual S-shaped ylide.…”

Construction of Enantiopure Pyrrolidine Ring System via Asymmetric [3+2]-Cycloaddition of Azomethine Ylides

“…Harwood et al . − also showed excellent diastereoselectivity in an intramolecular cycloaddition of in-situ-generated azomethine ylide 317 , produced by reaction of 315 and an aldehyde 316 (Scheme ), producing 318 as the only product. On the basis of semiempirical and ab initio quantum mechanical calculations it was suggested that the most favorable transition state involved an anti addition of the dipolarophile to the E -ylide ( E act ≈ 12 kcal/mol).…”

Semi-Empirical Computation on Mechanism of Imidazolines and Benzimidazoles Synthesis and Their QSAR Studies

“…Accordingly, we reported Bronsted acid catalyzed oxidation of alcohols to aldehydes and ketones in the presence of DMSO, where the catalyst HI was generated in a redox process of N2H4 and I2 2 . We also reported the use of I2 for the deprotection of keto and aldoximes/imines and oxidation of alcohols to aldehydes and ketones in water 3,4 .Recently, a practical, inexpensive and green method for the synthesis of imidazolines and benzimidazoles in water using I2/ KI/K2CO3/H2O system under anaerobic conditions is also reported in the literature 1 . In this communication, we report a validation of this proposal by quantum mechanical calculations.…”

“…Accordingly, we reported Bronsted acid catalyzed oxidation of alcohols to aldehydes and ketones in the presence of DMSO, where the catalyst HI was generated in a redox process of N2H4 and I2 2 . We also reported the use of I2 for the deprotection of keto and aldoximes/imines and oxidation of alcohols to aldehydes and ketones in water 3,4 .…”