Selective remote C–H sulfonylation of aminoquinolines with arylsulfonyl chlorides via copper catalysis

Abstract

Copper-catalysed direct C-H bond sulfonylation of aminoquinolines using commercially available and inexpensive arylsulfonyl chlorides as the sulfonylation reagents is described. The reactions took place exclusively at the C5-H position of the quinoline rings and tolerated a wide spectrum of functional groups. Moreover, synthetic transformations of the sulfonylated products led to useful compounds.

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

“…N ‐[5‐(toluene‐4‐sulfonyl)‐quinolin‐8‐yl]‐butyramide ( 4a ) . White solid; mp 165‐166°C; 1 H NMR (400 MHz, CDCl 3 ): δ = 10.03 (s, 1 H), 9.04‐9.02 (m, 1 H), 8.88 (d, 1 H, J = 8.0 Hz), 8.81‐8.05 (m, 1 H), 8.49 (d, 1 H, J = 8.0 Hz), 7.81 (d, 2 H, J = 8.0 Hz), 7.56‐7.53 (m, 1 H), 7.26 (t, 2 H, J = 6.0 Hz), 2.58‐2.54 (t, 2 H, J = 8.0 Hz), 2,35 (s, 3 H), 1.87‐1.81 (m, 2 H), 1.05 (t, 3 H, J = 8.0 Hz).…”

“…N ‐(5‐tosylquinolin‐8‐yl)pentanamide ( 4c ) . Yellow liquid; 1 H NMR (400 MHz, CDCl 3 ): δ = 10.03 (s, 1 H), 9.03 (d, 1 H, J = 8.0 Hz), 8.87 (d, 1 H, J = 12.0 Hz), 8,81 (d, 1 H, J = 8 Hz), 8.48 (d, 1 H, J = 12.0 Hz), 7.81 (d, 1 H, J = 8.0 Hz), 7.56‐7.53 (m, 1 H), 7.25 (d, 2 H, J = 8.0 Hz), 2.58 (t, 2 H, J = 8.0 Hz), 2.35 (s, 3 H), 1.79 (t, 2 H, J = 8.0 Hz), 1.48‐1.43 (m, 2 H), 0.97 (t, 3 H, J = 8.0 Hz); 13 C NMR (100 MHz, CDCl 3 ): δ = 172.4, 148.5, 144.0, 139.8, 139.1, 138.1, 133.4, 132.0, 129.8, 129.0, 127.2, 124.2, 123.1, 114.1, 38.0, 27.5, 22.3, 21.5, 13.7; ESI‐MS (M + H) + : 383.…”

“…N ‐(5‐(phenylsulfonyl)quinolin‐8‐yl)acetamide ( 4e ) . Brown solid; mp 102‐103°C; 1 H NMR (400 MHz, CDCl 3 ): δ = 10.02 (s, 1 H), 9.03 (d, 1 H, J = 8.0 Hz), 8.86 (d, 1 H, J = 8.0 Hz), 8.82 (s, 1 H), 8.50 (d, 1H, J = 8.0 Hz), 7.93 (d, 2 H, J = 8.0 Hz), 7.55‐7.51 (m, 2 H), 7.48 (d, 2 H, J = 8.0 Hz), 2.37 (s, 3 H); 13 C NMR (100 MHz, CDCl 3 ): δ = 169.1, 148.5, 141.9, 139.9, 133.4, 133.1, 132.3, 129.2, 127.1, 123.2, 114.1, 25.2; ESI‐MS (M + H) + : 327.…”

“…Yet on the other hand, the sulfonylation of the C5‐H bond in the quinoline ring directed by the amide fragment has in recently years emerged as a highly useful tool in providing sulfonylated quinolines (B, Scheme ). 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.…”

Copper‐Catalyzed 8‐Amido Chelation‐Induced Remote C−H Amination of Quinolines

“…Stahl and co-workersd emonstrated the copper-catalyzed C5-chlorination of quinolines in acetic acid. [14] To the besto fo ur knowledge these are the few examples known for the catalytic direct CÀHb ond functionalization at the C5-position of quinolines. [13] Recently, Wei and co-workersr eported the C5-sulfonylation using arylsulfonyl chlorides with ac opper catalyst.…”