Copper-Catalyzed Remote C-H Sulfonylation of 8-Aminoquinoline Amides with Arylsulfonyl Hydrazides

Abstract

An efficient copper‐catalyzed remote C‐5 sulfonylation of 8‐aminoquinoline amides using stable and readily available arylsulfonyl hydrazides has been developed. In the presence of 10 mol‐% Cu(OAc)2 as a catalyst and Ag2CO3 as an oxidant, a wide range of 8‐aminoquinoline amides underwent sulfonylation with arylsulfonyl hydrazides to generate structurally diverse aryl sulfones in moderate to good yields.

Recent Advances in the Catalytic Synthesis of Arylsulfonyl Compounds

“…The Liu group employed arylsulfonyl hydrazide as an arylsulfonylating reagent in their copper-catalyzed remote C5-sulfonylation of N -(quinolin-8-yl)­benzamide derivatives . When Cu­(OAc) 2 (10 mol %) and Ag 2 CO 3 (3 equiv) were used, the desired products were formed in high yields.…”

“…The Liu group employed arylsulfonyl hydrazide as an arylsulfonylating reagent in their copper-catalyzed remote C5sulfonylation of N-(quinolin-8-yl)benzamide derivatives. 43 When Cu(OAc) 2 (10 mol %) and Ag 2 CO 3 (3 equiv) were used, the desired products were formed in high yields. The proposed mechanism pathway was analogous to that of previously reported copper-catalyzed remote C5-sulfonylation, except for the formation of a sulfonyl radical.…”

Oxidative Sulfonylation of Multiple Carbon‐Carbon bonds with Sulfonyl Hydrazides, Sulfinic Acids and their Salts

“…[215] Replacing of sodium sulfinates with sulfonyl hydrazides and application of Cu(OAc) 2 /Ag 2 CO 3 system in 1,4-dioxane at 100°C resulted in 5-sulfonylated derivatives of 8-benzamidoquinolines too. [216] Cu(II)-mediated sulfonylation of quinolines at the 5 th position runs in the copper coordination sphere (Scheme 167). In the first step, chelate complex A is formed from copper (II) and the starting amidoquinoline 378.…”

“…5‐Sulfonyl 8‐benzamidoquinolines 380 were also synthesized using sodium sulfinates 379 as sulfonylation reagents and copper (II) acetate as the catalyst: the best results were achieved with Na 2 CO 3 and TBPB in acetone at 60 °C (Scheme 166). [215] Replacing of sodium sulfinates with sulfonyl hydrazides and application of Cu(OAc) 2 /Ag 2 CO 3 system in 1,4‐dioxane at 100 °C resulted in 5‐sulfonylated derivatives of 8‐benzamidoquinolines too [216] …”

One‐pot reactions for the synthesis of 5‐sulfonyl quinolines via domino N‐acylation and remote C‐H sulfonylation

“…Predominantly, the selective C5‐H sulfonylation of N ‐acyl 8‐aminoquinolines by employing sulfonyl chlorides as sulfonylating reagents has been reported by several groups via copper catalysis . Later on, sulfinate salts and sulfonyl hydrazides were also successfully utilized as the sulfonyl sources for the synthesis of these products, respectively.…”