- Smooth isoindolinone formation from isopropyl carbamates via bischler-napieralski-type cyclization
-
Isopropyl carbamates derived from benzylamines provide isoindolinones by treatment with phosphorus pentoxide at room temperature. Utility of this Bischler-Napieralski-type cyclization and a new mechanism involving a carbamoyl cation for rationalization of this smooth conversion are discussed.
- Adachi, Satoshi,Onozuka, Masao,Yoshida, Yuko,Ide, Mitsuaki,Saikawa, Yoko,Nakata, Masaya
-
p. 358 - 361
(2014/04/03)
-
- The photodecarboxylative addition of carboxylates to phthalimides: Scope and limitations
-
Intermolecular photoinduced decarboxylative additions of a series of alkylcarboxylates to N-substituted phthalimides gave the corresponding hydroxyphthalimidines in moderate to high yields of 39-89%. The potassium salt of 1-adamantanecarboxylic acid predominately underwent simple decarboxylation when irradiated in the presence of N-methylphthalimide. In case of phthalimides carrying suitable leaving groups within the N-side chain, decarboxylation, retro-Aldol cleavage or decarbonylation preceded the intermolecular addition step.
- Oelgemoeller, Michael,Cygon, Peter,Lex, Johann,Griesbeck, Axel G.
-
p. 669 - 684
(2007/10/03)
-
- Reactivity of Carbamoyl Radicals. A New, General, Convenient Free-Radical Synthesis of Isocyanates from Monoamides of Oxalic Acid
-
A new, general, simple synthesis of isocyanates was developed by oxidation of monoamides of oxalix acid with peroxydisulfate catalyzed by Ag and Cu salts.The reaction was carried out in a two-phase system (water and an organic solvent), and it is suitable also for practical applications, due to the simple experimental conditions and the inexpensive as well as nontoxic reagents.The first example of homolytic intramolecular aromatic carbamoylation is also reported.
- Minisci, Francesco,Fontana, Francesca,Coppa, Fausta,Yan, Yong Ming
-
p. 5430 - 5433
(2007/10/02)
-
- The mechanism of electrochemical reduction of N-haloamides in acetonitrile: trapping of intermediate amide anions and father-son protonation
-
The electrochemical reduction of N-haloamides (ZCONRX) in acetonitrile involves two consecutive one-electron transfers and generates the amide anions.Attempts to trap the intermediate amidyl radical resulting from first electron transfer were unssuccesful.In the case of the N-halo-N-hydroamides (R=H), the amide anion formed at the electrode abstracts a proton from an incoming N-halo-N-hydroamide molecule to give the parent amide and the conjugate base of the N-haloamide (father-son protonation).Thus, half of the N-halo-N-hydroamide reaching the electrode is reduced, the other half being converted to its conjugate base.In acetonitrile-LiClO4 (0.2 M) containing 0.2percent water, the conjugate base is reducible and polarograms therefore show two waves (irreversible and diffusion controlled) of equivalent intensities due respectively to the reduction of the N-halo-N-hydroamide and to the reduction of its conjugate base.In the case of the N-chloro-N-alkyl(aryl)amides (X=Cl, R=alkyl or aryl), the amide anion abstracts a proton from the medium to give the parent amide and anionic species that react with the starting N-chloroamide regenerating the amide anion.Hence, the coulometric results are low (0.5 F/mol).However, in the presence of acetic acid, the reduction consumes 2 F/mol as expected.The N-alkylamide anion has been trapped by N-alkylation and N-acylation.The voltammograms of N-chloro-N-alkyl(aryl)amides show multiple waves on mercury and platinum due to passivation-adsorption phenomena but a single wave on vitreous carbon.
- Berube, Denis,Lessard, Jean
-
p. 1127 - 1142
(2007/10/02)
-