One-pot cascade synthesis of N-methoxyisoquinolinediones via Rh(iii)-catalyzed carbenoid insertion C–H activation/cyclization

Abstract

Here a new, mild and versatile method for one-pot cascade synthesis of diverse N-methoxyisoquinolinediones via Rh(III)-catalyzed regioselective carbenoid insertion C-H activation/cyclization of N-methoxybenzamides with α-diazotized Meldrum's acid has been achieved. Extension of the developed Rh(III) catalysis for building new analogs of the marketed drug Edaravone has also been demonstrated.

Rh(III)- and Ir(III)-Catalyzed C–C Bond Cross Couplings from C–H Bonds

“…Asymmetric version was subsequently reported by Cramer [105]. Besides, carbonyl-containing diazo precursors (Scheme 8b, c) or diazotized Meldrum's acid (Scheme 8d), used as "two-carbon components," enables tandem C-H activation/cyclization/condensation reaction sequence delivering valuable heterocyclic skeletons like isoquinolines and pyridine N-oxides [106], isocoumarins and α-pyrones [107], cinnolin-3(2H )-one derivatives [108], or Nmethoxyisoquinolinediones [109]. Finally, C-H activation/[4+3] cycloaddition cascade transformations could be envisioned in the presence of vinylcarbenoids, hence enabling the expedient construction of generally difficult-to-prepare sevenmembered azepinone scaffolds (Scheme 8e) [110].…”

One‐Pot Synthesis of 3‐Iminoisoindolinones by a Rhodium(III)‐Catalyzed and Methanol‐Assisted C−H Cyanation–Cyclization Cascade with N‐Alkoxyl Transfer

“…Since it was introduced by the Fagnou group, [3] and to date, al arge number of important mono-N-heterocycles have been efficiently constructed by using aN -OR group as both DG and nitrogen atom source through transition-metalcatalyzed CÀHa ctivation/cyclization with various coupling partners. [4][5] However,t ot he besto fo ur knowledge,s of ar only aPd-catalyzed protocolf or direct synthesis of di-N-heterocycle 3-iminoisoindolinones hasb een reported by the Yu group.[6] Clearly,m ore efforts are neededt oe xplore and develop new transition-metal-catalyzed CÀHa ctivation reactions for building this privileged structural motif.Inspired by these studies and with our continued interest in Rh III -catalyzedc yclization towards N-heterocycles synthesis, [7] we herein report an ew and mild Rh III -catalyzed and MeOH-assisted direct CÀHf unctionalization of simple N-alkoxybenzamides by using N-cyano-N-phenyl-p-toluenesulfonamide (NCTS) as an environmentally friendly and highly efficient coupling partner [8] for the one-pot synthesis of 3-iminoisoindolinones with excellent regioselectivity and substrate/functional group tolerance. Notably,t he versatile reaction comprises ar egioselectiveC ÀHc yanation and subsequent intramolecular cyclization along with N-alkoxyl transfer (Scheme 1).…”

Security Analysis of MAC Protocol for Mobile Device Identification Based on PARADIS

“…1). 5 Even more recent examples of Rh(III)-catalyzed cyclization using diazo compounds as coupling/cyclization partners have come from the groups of Glorius, 6 Cui,7 Cramer, 8 Wang, 9 Yu 10 and Yi,11 but all these elegant transformations are restricted to C-C/C-N bonds formation to generate N-heterocycles such as isoindolinones, isoquinoline Noxides, azepinones and 1-aminoindoles (Scheme 1, eq. 2).…”

“…2). [6][7][8][9][10][11] To the best of our knowledge, C-C/C-O bonds formation via Rh(III)catalyzed C-H activation/cyclization of aromatics with diazo compounds has not been reported yet.…”

“…The pyrrolidinyl group performed much better than any other groups we tested. The catalysts [Cp*Rh(CH 3 CN) 3 ](SbF 6 ) 2 and [Cp*RhCl 2 ] 2 showed similar activity, whereas Cp*Rh(OAc) 2 , Pd(OAc) 2 or [RuCl 2 (p-cymene)] 2 showed little or even no activity in this transformation (entries [8][9][10][11]. Therefore we selected [Cp*RhCl 2 ] 2 as the catalyst and investigated various additives (entries 12-18).…”