- Sulfate Radical Anion (SO4?-) Mediated C(sp3)-H Nitrogenation/Oxygenation in N-Aryl Benzylic Amines Expanded the Scope for the Synthesis of Benzamidine/Oxazine Heterocycles
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A transition-metal-free, K2S2O8-mediated intramolecular oxidative nitrogenation/oxygenation of C(sp3)-H in N-aryl benzylic amines followed by oxidation at the benzylic center has been developed for the synthesis of benzamidine/benzoxazine heterocycles, providing an expedient access to quinazolin-4(3H)-ones, N-aryl-2-arylbenzimidazoles, and 4H-3,1-benzoxazin-4-ones. A considerable amount of work dealing with the mechanistic study to understand the crucial intramolecular cyclization step largely favors an iminium ion as the key intermediate.
- Laha, Joydev K.,Tummalapalli, K. S. Satyanarayana,Nair, Akshay,Patel, Nidhi
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p. 11351 - 11359
(2015/12/01)
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- N-benzylation/benzylic C-H amidation cascade by the (ζ3- Benzyl)palladium system in aqueous media: An effective pathway for the direct construction of 3-phenyl-3,4-dihydro-(2H)-1,2,4-benzothiadiazine 1,1-dioxides
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We demonstrate a unique strategy for a benzylation/benzylic C-H amidation cascade reaction by the (ζ3-benzyl)palladium system derived from a palladium catalyst and benzyl alcohol. This tandem process is devised as a new synthetic route for 3-phenyl-3,4-dihydro-(2H)-1,2,4-benzothiadiazine-1,1- dioxide. Water plays an important role for the smooth generation of the (ζ3-benzyl)palladium species, and a bis-benzylated Pd(II) intermediate would be formed in our catalytic system. Atom economical processes such as benzylic C-H activation, cascade reactions and chemoselective reactions in aqueous media have been developed.
- Hikawa, Hidemasa,Matsuda, Naoya,Suzuki, Hideharu,Yokoyama, Yuusaku,Azumaya, Isao
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p. 2308 - 2320
(2013/10/01)
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