Photolysis of Regioisomeric α,α-Diphenyl-Substituted Diazotetrahydrofuranones: Primary and Secondary Photochemical Processes
作者:L. L. Rodina、O. S. Galkina、M. B. Supurgibekov、Ya. M. Grigor’ev、V. A. Utsal’
DOI:10.1134/s1070428010100179
日期:2010.10
The formation of C–H insertion products in the course of direct photolysis of α,α-diphenylsubstituted diazo ketones of the tetrahydrofuran series was rationalized by secondary photochemical processes which give rise to benzophenone acting as a sensitizer. Triplet excited states of diazo ketones generated by the action of benzophenone are capable of undergoing bimolecular transformations.
Surprising secondary photochemical reactions observed on conventional photolysis of diazotetrahydrofuranones
作者:Valerij A. Nikolaev、Olesja S. Galkina、Jochim Sieler、Ludmila L. Rodina
DOI:10.1016/j.tetlet.2010.03.050
日期:2010.5
during direct photolysis of regioisomeric 2,2-dimethyl-5,5-diphenyl and 5,5-dimethyl-2,2-diphenyl-substituted 3-diazotetrahydrofuran-4-ones in THF is dictated by photochemical cycloelimination of the originally formed (1,1-dimethyl-2-oxa-3,3-diphenyl-propano)ketene and oxetanecarboxylic acid derivatives to yield benzophenone. The latter, under subsequent UV irradiation of the reaction mixture, initiates
Thermolysis of 4-Diazotetrahydrofuran-3-ones: Total Change of Reaction Course Compared to Photolysis
作者:Ludmila L. Rodina、Jury J. Medvedev、Olesia S. Galkina、Valerij A. Nikolaev
DOI:10.1002/ejoc.201400161
日期:2014.5
Thermolysis of 2,2,5,5-tetrasubstituted 4-diazodihydrofuran-3-ones in protic (BnOH) and aprotic (DMSO) media, in contrast to photolysis, gives rise to the formation of 2,2,4,5-substituted 3(2H)-furanones as a result of 1,2-alkyl (aryl) shift. The thermal stability of diazodihydrofuranones in these processes is determined by the nature of the substituents at the C-5 atom of the heterocyclic structure:
Photochemical Reactions of Regioisomeric 2,2-Dimethyl-5,5-diphenyl- and 5,5-Dimethyl-2,2-diphenyl-Substituted Diazo Ketones of a Tetrahydrofuran Series
作者:Ludmila L. Rodina、Sergey A. Malashikhin、Olesya S. Galkina、Valerij A. Nikolaev
DOI:10.1002/hlca.200900079
日期:2009.10
2‐dimethyl‐5,5‐diphenyl‐ and 5,5‐dimethyl‐2,2‐diphenyl‐substituted 4‐diazodihydrofuran‐3(2H)‐ones 1a and 1b, respectively, is the Wolff rearrangement, while other photochemical processes, which are giving rise to the formation of CH‐insertion, 1,2‐alkyl‐ or ‐aryl‐shifts, as well as H‐atom‐abstraction products occur to a much lower degree (Schemes 2 and 3). The ratio of similar reaction products from