Ir(III)‐Catalyzed C7‐Position‐Selective Oxidative CH Alkenylation of Indolines with Alkenes in Air

Abstract

An efficient method for C7-position-selective alkenylation of N-substituted indolines with alkenes is reported. Various 7-alkenylindolines were obtained in moderate to excellent yields in air in the presence of catalytic amounts of [Cp*IrCl2]2, AgOTf, and Cu(OAc)2. The protocol relies on the use of a carbonyl or carbamoyl group on the nitrogen atom of indoline as a directing group and is potentially applicable to the synthesis of 7-alkenylindoles and 7-alkylindoles.

Mild Rh(III)-Catalyzed C7-Allylation of Indolines with Allylic Carbonates

“…1, 143.8, 130.2, 127.6, 124.5, 121.6, 114.6, 47.0, 40.3, 32.3, 27.8, 20.1, 13.8;IR (KBr) υ 3344, 2956, 2861, 1643, 1520, 1480, 1461, 1386, 1339, 1292, 1153, 1088, 1022 155.3, 141.5, 131.3, 130.6, 128.1, 125.5, 114.4, 47.3, 40.4, 32.5, 28.0, 21.0, 20.3, 14.0;IR (KBr) υ 3338, 2957, 2861, 1523, 1487, 1384, 1332, 1263, 1160, 1133 (d,J = 8.1 Hz,1H),7.19 (td,J = 8.6,1.3 Hz,1H),7.08 (d,J = 7.4 Hz,1H),6.94 (td,J = 7.8,0.9 Hz,1H) 155.0, 154.8, 142.7, 137.8, 128.4, 122.5, 122.0, 114.4, 79.8, 56.6, 42.7, 40.3, 36.5, 32.3, 29.7, 28.4, 20.1, 13.8;IR (KBr) υ 3325, 2925, 2847, 1638, 1520, 1477, 1456, 1341, 1279, 1220, 1152, 1095 9, 147.0, 143.1, 138.6, 128.4, 128.1, 126.6, 126.4, 123.9, 122.1, 114.7, 64.1, 47.8, 40.2,...…”

“…3, 143.6, 136.5, 133.6, 131.5, 128.3, 123.7, 122.4, 116.0, 52.9, 50.5, 38.3, 37.4, 30.6;IR (KBr) υ 2924, 1650, 1482, 1451, 1377, 1292, 1258, 1166, 1062, 1006 (7-Allylindolin-1-yl)(pyrrolidin-1-yl)methanone (3d). 9.1 mg (12%); light yellow sticky solid; 1 H NMR (700 MHz, CDCl 3 ) δ 6.98 (d, J = 6.9 Hz, 1H), 6.92 (d,J = 7.5 Hz,1H) 3, 143.5, 136.9, 131.4, 128.6, 123.6, 122.5, 115.8, 52.2, 50.2, 48.0, 37.8, 30.6, 28.7, 25.7;IR (KBr) υ 2874, 1966, 1592, 1452, 1383, 1285, 1254, 1196, 1124, 1048 3, 141.5, 138.5, 136.3, 135.6, 129.3, 129.2, 129.0, 125.2, 123.5, 123.3, 119.6, 116.8, 52.0, 36.9, 30.2;IR (KBr) υ 3263, 3051, 2926, 1998, 1650, 1594, 1479, 1439, 1343, 1315, 1240, 1141, 1025 3, 142.2, 136.8, 135.5, 129.1, 128.7, 124.6, 123.0, 116.3, 51.9, 40.7, 36.9, 32.4, 30.1, 20.3, 14.0;IR (KBr) υ 3313, 3051, 2929, 1993, 1522, 1482, 1152, 1086 5, 139.9, 136.8, 135.8, 134.3, 129.4, 128.3, 123.9, 116.3, 52.0, 40.7, 36.7, 32.4, 30.1, 21.1, 20.2, 13.9;…”

“…33.0 mg (55%); light yellow sticky solid; 1 H NMR (700 MHz, CDCl 3 ) δ 7.07−7.02 (m, 3H), 5.86 (ddt,J = 17.0,10.1,6.7 Hz,1H),2H),4.03 (s,2H),3.42 (d,J = 6.3 Hz,2H), 3.00 (t, J = 7.2 Hz, 2H), 2.24 (s, 3H); 13 C NMR (175 MHz, CDCl 3 ) δ 168.6, 141.1, 136.8, 134.7, 129.0, 125.5, 125.0, 122.4, 116.0, 51.3, 38.4, 30.1, 23.9;IR (KBr) υ 2915, 1993, 1658, 1591, 1429, 1379, 1327, 1234, 1186, 1105 2, 143.0, 136.7, 134.5, 131.6, 128.5, 125.2, 122.3, 116.1, 51.3, 40.1, 38.3, 31.3, 28.7;IR (KBr) υ 2963, 1967, 1648, 1587, 1430, 1347, 1322, 1183, 1149, 1088 ; HRMS (quadrupole, EI) m/z calcd for C 16 H 21 NO [M] + 243.1623[M] + 243. , found 243.1622. 24.2 mg (35%); light brown sticky solid; 1 H NMR (700 MHz, CDCl 3 ) δ 7.02 (d,J = 7.2 Hz,1H),6.97 (d,J = 7.1 Hz,1H),6.93 (t,J = 7.4 Hz,1H),5.82 (ddt,J = 17.0,10.0,6.8 Hz,1H),2H),2H),…”

“…23a 1.33 g (78%); light brown solid; mp = 54−58°C; 1 H NMR (500 MHz, CDCl 3 ) δ 8.23 (d,J = 8.5 Hz,1H),2H), 7.02 (t, J = 7.0 Hz, 1H), 4.23 (t, J = 8.1 Hz, 2H), 3.14 (t, J = 8.1 Hz, 2H), 1.38 (s, 9H); 13 C NMR (100 MHz, CDCl 3 ) δ 176. 5, 144.7, 130.7, 127.3, 124.2, 123.6, 118.4, 49.4, 40.2, 29.3, 27.7. N,N-Dimethylindoline-1-carboxamide (1c).…”

Rhodium(III)‐ and Iridium(III)‐Catalyzed C7 Alkylation of Indolines with Diazo Compounds

“…Later, a palladium‐catalyzed C7 arylation of indolines was developed by several groups (Scheme b) 4b–e. Recently, an oxidative transition‐metal‐catalyzed C7 alkenylation of indolines was reported by several groups (Scheme c)4f–i and Shibata and Sanford reported the transition‐metal‐catalyzed C7 alkylation of indolines (Scheme d) 4j–k. Given the prevalence of 7‐substituted indoles in numerous natural products, pharmaceutically important compounds, and marketed drugs (Figure 1),5 the development of efficient methods that will enable high‐yielding and selective formation of valuable C7 substituted indoles (especially under mild and pH‐neutral reaction conditions) is highly desirable.…”