Acid catalyzed coupling of aromatic aldehydes and methyldiazoacetatea theoretical mechanistic studyElectronic supplementary information (ESI) available: Cartesian coordinates and electronic energies, enthalpies, and free energies for all calculated compounds and transition states at the B3LYP/6-31G level. See DOI: 10.1039/c2nj20824e

• Main Authors: Dazinger, Georg, Kirchner, Karl A
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c2nj20824e

The proton catalyzed reaction of methyldiazoacetate and benzaldehyde resulting in the formation of -ketoesters and 3-hydroxyacrylates has been investigated by means of DFT/B3LYP calculations. Experimentally this reaction is performed using HBF 4 Et 2 O as the catalyst and CH 2 Cl 2 as the solvent. Several mechanistic pathways involving 1,2-migration of phenyl-, H-, and OH-substituents have been considered. In agreement with the experiment, phenyl migration is slightly favored over H- and OH-migrations and thus the formation of 3-hydroxyacrylates over -ketoesters takes place. Epoxide formation is not feasible in the presence of acid with non-nucleophilic counterions. Moreover, a counterion-assisted pathway has been also taken into account. The overall reaction is similar and competitive to the BF 4 -free pathway. The proton catalyzed reaction of methyldiazoacetate and benzaldehyde resulting in the formation of -ketoesters and 3-hydroxyacrylates has been investigated by means of DFT/B3LYP calculations. Several mechanistic pathways involving 1,2-migration of phenyl-, H-, and OH-substituents have been considered.