Transition-Metal-Controlled Synthesis of 11H-Benzo[a]carbazoles and 6-Alkylidene-6H-isoindo[2,1-a]indoles via Sequential Intermolecular/Intramolecular Cross-Dehydrogenative Coupling from 2-Phenylindoles

Scalable Rhodaelectro-Catalyzed Expedient Access to Seven-Membered Azepino[3,2,1- hi ]indoles via [5 + 2] C–H/N–H Annulation

“…Replacing Li 2 CO 3 with other additives, such as NaOPiv, K 3 PO 4 , n Bu 4 NPF 6 , K 2 CO 3 and Na 2 CO 3 , resulted in a sharp decrease in yield (entries 6-10). Increasing or decreasing the amount of Li 2 CO 3 also reduced the yield (entries [11][12]. Control experiments verified the crucial role of Li 2 CO 3 , rhodium catalysts and electricity (entries [13][14][15].…”

Rh(iii)-catalyzed regioselective C–H activation dialkenylation/annulation cascade for rapid access to 6H-isoindolo[2,1-a]indole

“…First, possible active rhodium catalytic species A was synthesized according to previous reports ( Scheme 4a ). 13 Next, catalytic reaction of rhodium complex A with ethyl acrylate 2a under standard reaction conditions gave rise to desired product 3a in 53% yield ( Scheme 4b ), which indicate complex A possibly involves in this reaction. Thirdly, only mono- and di- alkenylation products were obtained in the absence of base while the cyclization product 3a produced by further extra addition of CsOAc ( Scheme 4b ).…”

“…Recently, Huang et al reported a N–H indole directed sequential cascade olefination/cyclization reaction ( Scheme 1c ). 13 However, the substrate scope of this transformation is limited, stepwise operation procedure is required, thus make this process tedious. Herein, we reported a Rh-catalyzed N–H free indole directed dialkenylation followed by an intramolecular cascade cyclization reaction leading to the efficient synthesis of 6 H -isoindolo[2,1- a ]indole.…”

Rhodium-Catalyzed Oxidative Annulation of 2- or 7-Arylindoles with Alkenes/Alkynes Using Molecular Oxygen as the Sole Oxidant Enabled by Quaternary Ammonium Salt

“…Since then, rhodium-catalyzed oxidative C-H coupling has drawn increasing attention, and many important organic building blocks have been produced [23][24][25][26][27][28][29][30]. However, despite indisputable advances, all rhodium-catalyzed C-H oxidative coupling reactions are extremely limited to hazardous and stoichiometric oxidants such as AgOAc [31][32][33][34][35][36][37] and Cu(OAc) 2 [38][39][40][41][42][43][44][45][46][47]. The use of molecular oxygen is advantageous over other oxidants because only water is generated as a by-product [48][49][50][51][52][53][54].…”