Rh(II)-Catalyzed Synthesis of N-Aryl 2-pyridone Using 2-Oxypyridine and Diazonaphthoquinone Via 1,6-Benzoyl Migratory Rearrangement

Abstract

A Rh(II)-catalyzed simple and efficient synthesis of N-arylated 2-pyridone derivatives is described using 2-oxypyridine and diazonaphthoquinone as coupling partners. The reaction proceeds through the insertion of the nitrogen atom of the 2-oxypyridine derivative into quinoid carbene and subsequent 1,6-benzoyl migratory rearrangement. The reaction is broadened with sufficient scope and has the potential to offer axially chiral N-arylated 2-pyridone derivatives under suitable asymmetric conditions.

Regioselective ortho C–H insertion of N-nitrosoanilines with naphthoquinone carbenes

“…On the basis of the above control experiments and preceding literature reports, 6,11 c ,14 a plausible mechanistic pathway was proposed (Scheme 8). The active catalyst I was formed through the reaction of [Cp*RhCl 2 ] 2 with AgSbF 6 and NaOAc.…”

P(NMe2)3-Mediated Regioselective N-Alkylation of 2-Pyridones via Direct Deoxygenation of α-Keto Esters

“…Although direct N-alkylation could also be realized under certain conditions, reaction partners were strictly restricted to active allenes or allylic alcohol derivatives (Scheme b) . Given that diazo compounds, as important carbine precursors, can readily undergo X–H insertion reactions, the direct N-alkylation of 2-pyridones with diazo compounds investigated by Sun and co-workers and Samanta and co-workers usually employed prefunctionalized 2-oxypyridines as reaction partners (Scheme c). Considering the issues of stability and storage for diazo compounds, alternative protocols with more stable and safer hydrazones, sulfoxonium ylides, and other carbene surrogates have also been well explored.…”

Rh(ii)-catalysed N2-selective arylation of benzotriazoles and indazoles using quinoid carbenes via 1,5-H shift

“…9,10 However, the N–H arylations using the quinoid carbene species are scarce. 11 Driven by our early interests in the insertion of quinoid carbenes, especially for the directed CH-arylations 12 and NH-arylations, 13 we hypothesized that the control of N 2 -arylation over N 1 -arylation might be possible with quinoid carbene species as the catalyst can differentiate the energy difference between N 2 and N 1 intermediate. Herein we describe the Rh( ii )-catalyzed highly selective N 2 -arylation using diazonaphthoquinone as a coupling partner (Scheme 1d).…”