Carbethoxynitrene. Control of Chemical Reactivity

Study of photochemical transformations of organic azides by matrix isolation techniques and quantum chemistry

“…98 Scheme 1 In the photolysis of azide 15, the yield of the products generated in the reaction of nitrenes was *70%. 104,105 The analysis of aziridines showed that singlet 1 (16) and triplet 3 (16) nitrenes are simultaneously formed in the primary process in a ratio of 2 : 1. 98, 105 Singlet nitrene 1 (16) is also inserted into the C7H bonds of alkanes and O7H bonds of alcohols and is captured by alkynes and benzene to form azepine.…”

Photolysis of 3,5‐diphenylisoxazole in argon matrices

“…For example, triplet carboalkoxynitrenes are short-lived, as they abstract H atoms from the solvent. [5][6][7] In comparison, triplet alkylnitrenes and arylnitrenes are less reactive and longer-lived, as they do not react with the solvent, but mainly decay by dimerization (Scheme 1). [8][9][10][11][12][13] Because triplet alkylnitrenes and arylnitrenes have high spin properties and are long-lived, they have a potential as building blocks for high spin assemblies.…”

Photochemistry of Azides: The Azide/Nitrene Interface

“…Formation of products characteristic of reactions of carbethoxynitrene 1 43 have been observed by thermolysis and photolysis of azide 42 143,146 and by α -elimination of arysulfonate ion from N -( pnitrobenzenesulfonyloxy) urethane. 143,145 The reaction of 1 43 with cis and trans -4 -methyl -2 -pentene was studied as a function of alkene concentration. At large alkene concentrations, aziridination is stereospecifi c, but upon dilution of the alkene, the stereospecifi city is lost.…”

“…At large alkene concentrations, aziridination is stereospecifi c, but upon dilution of the alkene, the stereospecifi city is lost. 143 The triplet nitrene 3 43 also reacts with the olefi ns, but non -stereospecifi cally, presumably through intermediate biradical formation (Scheme 11.21 ). 107, 143 These results are completely analogous to studies of carbenes in which a stereospecifi c singlet intermediate is produced initially, and subsequently relaxes to a less selective, lower energy triplet intermediate.…”

“…143 The triplet nitrene 3 43 also reacts with the olefi ns, but non -stereospecifi cally, presumably through intermediate biradical formation (Scheme 11.21 ). 107, 143 These results are completely analogous to studies of carbenes in which a stereospecifi c singlet intermediate is produced initially, and subsequently relaxes to a less selective, lower energy triplet intermediate. 147 Insertion of 1 43 into the CH bond of alkanes and the OH bond of alcohols, addition of 1 43 to acetylenes, and its reaction with benzene, followed by azepine formation, are all well documented.…”