Rh(III)‐Catalyzed C−H Functionalization of N‐Nitrosoanilines with α‐Sulfonylcarbenes

Abstract

A Rh(III)-catalyzed ortho CÀ H functionalization of N-nitrosoanilines with α-sulfonylcarbenes had been developed. The reaction was carried out under mild conditions and the products were obtained with good to excellent yields. The diverse transformations of the products to ortho-functionalized anilines and nitrogen heterocycles were achieved. Furthermore, a cascade reaction of N-nitrosoanilines and α-sulfonyl-α-diazoketones provided 3-sulfonyl-indoles efficiently.

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.…”

“…The use of combinatory additives AbSbF 6 /AgOAc led to a better yield (Table 1, entry 3). 6 Further improvement was achieved by the combination of AbSbF 6 /NaOAc (Table 1, entry 4). A screening of reaction solvents indicated that DCE is the best choice (Table 1, entry 5).…”

“…Moreover, the versatility of these products was demonstrated through their transformation into ortho -alkyl anilines and nitrogen-containing heterocycles (Scheme 2). 6 Given the significance of biarylamines and their derivatives, we anticipate the extension of this strategy to ortho -arylation modifications of aromatic amines.…”

Metal-Free Synthesis of 2H-Indazole Skeletons by Photochemistry or Thermochemistry

“…Subsequently, the single electron transfer (SET) of J occurred with an arylsulfinic acid anion I to generate a peroxy anion K along with the formation of II or III . In intermediate K , the peroxy anion attacks the sulfur in K while breaking SO double bond to form the quaternary intermediate L . Finally, the intramolecular elimination of L delivered the final product 4a , along with arylsulfonate.…”

Approaches and Considerations for the Investigation and Synthesis of N-Nitrosamine Drug Substance-Related Impurities (NDSRIs)

“…Commercially available amines that lead to a corresponding nitrosamine that is also commercially available, stable, and facile to monitor analytically (MS and UV) are most suitable to use as a positive control (e.g., N-methylaniline). 24,27 Certain N-nitrosamines can form in solution as transient intermediates but are not sufficiently stable to be isolated. This can especially occur when the nitrosamine is unstable in the presence of water.…”