Synthesis of dihydroindazolo[2,3-f]phenanthridin-5(6H)-onesviaRh(iii)-catalyzed C–H activation of 2-aryl indazoles and annulation with iodonium ylides

Abstract

An efficient synthesis route of indazole fused dihydrophenanthridinones with excellent to almost quantitative yields under mild reaction conditions was developed by acid-controlled Rh(III)-catalyzed C-H activation of 3-arylindazoles and annulation with...

Rh(iii)-catalyzed C–H/C–C bond annulation of enaminones with iodonium ylides to form isocoumarins

“…Regrettably, the aliphatic iodonium ylides (2i-2m) did not proceed under standard conditions, which demonstrated that the transformation is sensitive to the size and nature of the dione compounds. 21 In order to gain deeper insight into the reaction mechanism, various control experiments were performed (Scheme 4). The hydrogen-deuterium exchange experiment of 1a with CH 3 COOD was conducted under standard conditions and the ortho-C(sp 2 )-H of the directing group was deuterated by 5% (Scheme 4a).…”

“…Regrettably, the aliphatic iodonium ylides ( 2i–2m ) did not proceed under standard conditions, which demonstrated that the transformation is sensitive to the size and nature of the dione compounds. 21…”

Rhodium(III)‐Catalyzed Divergent C−H Functionalization of N‐Aryl Amidines with Iodonium Ylides: Access to Carbazolones and Zwitterionic Salts

“…However, the silver salt was not obviously influent on the proton transfer product (entry 15). Further investigation of the additive effect revealed that K 3 [Fe-(CN) 6 ] was the optimal choice, providing the annulated product 4 aa in 62% yield with excellent chemoselectivity (entries [16][17][18]. When the loading of K 3 [Fe-(CN) 6 ] was increased to 1.5 equiv., 4 aa could be afforded in 75% yield (entry 19).…”

“…[11] In 2020, Li and co-workers firstly reported a Rh(III)-catalyzed CÀ H activation/annulations of various arenes with HVIs for the synthesis of diverse cyclic skeletons. [12] Since then, various [4 + 2], [3 + 3] and [3 + 2] cyclization reactions of HVIs with different synthons in CÀ H functionalization have been established to access privileged skeletons by Maheswari, [13] Ji, [14] Kanchupalli, [15] Peng, [16] Hu [17] and other groups. [18] In these transformations, HVIs were employed as two-atom or three-atom synthons.…”