Palladium(0)‐Catalyzed Heck Reaction/CH Activation/Amination Sequence with Diaziridinone: A Facile Approach to Indolines

Abstract

Indolines are important moieties present in various biologically significant molecules and have attracted considerable attention in synthetic chemistry. This paper describes a sequential Heck reaction/C–H activation/amination process to form indoline with di-tert-butyldiaziridinone. The reaction process likely proceeds via a pallada(II)cycle, which is converted to an indoline by oxidative addition to the diaziridinone and subsequent double C–N bond formation.

Palladium‐Catalyzed Synthesis of Indolines from Aroyloxycarbamates through a Tandem Decarboxylative Amination/Heck/Annulation Reaction

“…tert ‐butyl 1,2,3,4,4 a,9 a‐hexahydro‐9 H ‐1,4‐methanocarbazole‐9‐carboxylate ( 3 l ) . Yellow solid (38 mg, 44%); mp: 61–63 °C; R f =0.25 (hexane:EtOAc=100:1); 1 H NMR (400 MHz, CDCl 3 ) δ 7.80 (br, 0.65H), 7.40 (br, 0.35H), 7.13–7.08 (m, 2H), 6.91 (t, J =8 Hz, 1H), 4.17–4.09 (m, 1H), 3.23 (d, J =8 Hz, 1H), 2.69–2.58 (m, 1H), 2.30 (s, 1H), 1.63–1.55 (m, 11H) 1.36 (d, J=8 Hz, 1H), 1.30–1.26 (m, 3H), 1.07 (d, J =10 Hz, 1H); 13 C NMR (101 MHz, CDCl 3 ) δ 152.5, 144.6, 143.9, 134.4, 133.5, 127.5, 124.7, 124.2, 122.2, 114.2, 81.4, 80.2, 67.4, 49.9, 49.1, 43.2, 42.2, 41.4, 32.0, 28.5, 28.2, 25.5.…”

“…2,3,4,4 a,9,9 a‐hexahydro‐1 H ‐1,4‐methanocarbazole ( 3 o ) . White solid (22 mg, 39%); mp: 91–92 °C; R f =0.3 (hexane:EtOAc=20:1); 1 H NMR (400 MHz, CDCl 3 ) δ 7.03 (d, J =7.2 Hz, 1H), 6.98 (t, J =7.6 Hz, 1H), 6.65 (t, J =8 Hz, 1H), 6.51 (d, J =8 Hz, 1H), 3.77 (d, J =8 Hz, 1H), 3.61 (br, 1H), 3.28 (d, J =8 Hz, 1H), 2.30 (s, 1H), 2.20 (d, J =4 Hz, 1H), 1.62–1.49 (m, 3H), 1.39–1.34 (m, 1H), 1.24–1.14 (m, 2H); 13 C NMR (400 MHz, CDCl 3 ) δ 152.5, 131.9, 127.4, 124.5, 118.0, 108.3, 65.3, 52.4, 44.3, 43.2, 32.3, 28.6, 25.3.…”

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

“…A domino reaction in which norbornenes 23 reacted as a alkene substrate with aryl iodides 24 and di-tert-butyldiaziridinone (25) afforded the polycyclic N-tert-butylindolines 26 through a sequence of Heck reaction/C-H activation/amination process (Scheme 8). 11 The Heck reaction occurs from the exo face of the norbornene. The process was extended to various o-, m-, and p-substituted iodobenzenes, and among them also a bromo substituent was tolerated without interfering.…”

Intermediates for methyl carbon-hydrogen activation in binuclear dimethylfulvene ruthenium carbonyl complexes

“…The catalytic functionalization of unreactive C−H bonds has recently revolutionized synthetic methodologies for the production of pharmaceuticals and natural products and for providing new routes to molecular materials and polymers. 1,2,3 In this connection palladium, 4,5,6,7,8 rhodium, 9,10,11,12,13 cobalt, 14 manganese, 15 and iridium 16 complexes have been found useful for activating C−H bonds under mild conditions. 1 More recently, catalysts containing the less expensive metal ruthenium have been found to be more efficient in some systems for the catalytic activation of C−H bonds.…”