NaI-mediated divergent synthesis of isatins and isoindigoes: a new protocol enabled by an oxidation relay strategy

Abstract

A new approach for the synthesis of isatins and isoindigoes by an inexpensive and environmentally friendly NaI-mediated transformation is disclosed. The selectivity could be switched by simply varying the solvent, and isatins (using THF) and isoindigoes (using DMSO) could be obtained in moderate to excellent yields.

A tunable synthesis of indigoids: targeting indirubin through temperature

“… 14 ) and 34. 28 For 33 1 H NMR (300 MHz, d 6 -DMSO) δ – 11.18 (1H, s); 11.08 (1H, s); 8.68 (1H, d, J = 8.4 Hz); 7.69 (1H, d, J = 1.8 Hz) 7.60 (1H, d, J = 8.4 Hz); 7.24 (1H, dd, J = 6.3 Hz and 2.1 Hz); 7.21 (1H, dd, J = 6.6 Hz and 1.8 Hz) 7.06 (1H, d, J = 1.8 Hz). For 34 1 H NMR (300 MHz, d 6 -DMSO) δ – 10.21 (2H, s); 7.57 (2H, d, J = 8.1 Hz); 7.00 (2H, d, J = 1.5 Hz); 6.85 (2H, dd, J = 8.1 Hz and 1.5 Hz).…”

An Efficient Route to 3,3′‐Biindolinylidene‐diones by Iron‐Catalyzed Dimerization of Isatins

“…We assume that the oxindole is involved in an undesired reaction with Fe(0) and deactivating the catalyst, thus, the expected amount of 1 from 1 a (∼50%) is not obtained. Moreover, the oxindole did not participate in the dimerization reaction under the present catalytic condition (Scheme 4d) [7c] . All these findings highlight that the oxindole is less likely an intermediate for the isatin dimerization.…”

Transition-Metal-Free Addition Reaction for the Synthesis of 3-(Aminobenzylidene/aminoalkylidene)indolin-2-ones and Its Synthetic Applications

“…1-Benzylindoline-2,3-dione (4b). 23 3-(Aminobenzylidene/ aminoalkylidene)indolin-2-ones (3s, 3t, 3u) (0.1 mmol) and CuI (11 mg, 0.06 mmol) were allowed to react in a 10 mL round bottom flask according to method B to afford 1-benzylindoline-2,3-dione (for yield see Scheme 3 main article) red solid 4b. 1 H NMR (400 MHz, CDCl 3 ): δ 7.61 (d,J = 7.5 Hz,1H),7.47 (td,J = 7.8,1.4 Hz,1H),5H), 7.09 (td, J = 7.6, 0.8 Hz, 1H), 6.77 (d, J = 8.0 Hz, 1H), 4.93 (s, 2H).…”