1922-77-6Relevant articles and documents
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Sheehan et al.
, p. 4795 (1961)
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Phosphoric Acid Catalyzed 1,2-Rearrangements of 3-Hydroxyindolenines to Indoxyls and 2-Oxindoles: Reagent-Controlled Regioselectivity Enabled by Dual Activation
Schendera, Eva,Lerch, Stephanie,von Drathen, Thorsten,Unkel, Lisa-Natascha,Brasholz, Malte
supporting information, p. 3134 - 3138 (2017/06/21)
A common synthetic route to indoxyl and 2-oxindole alkaloids utilizes the oxidation of indoles to 3-hydroxyindolenines, followed by acid-mediated 1,2-rearrangement. However, controlling the regioselectivity is often challenging and there is an ongoing need for new reaction conditions allowing to steer product selectivity. We report herein that phosphoric acids are ideal organocatalysts for the highly regioselective 1,2-rearrangement of 3-hydroxyindolenines to 2-oxindoles, with predictable product selectivity arising from an efficient dual activation mode.
Alkylidenephosphoranes in heterocyclic synthesis: Reactivity of benzoxazinones with resonance-stabilized phosphorus ylides
Kamel, Azza A.,Abdou, Wafaa M.
, p. 1269 - 1273 (2007/12/27)
2H-3,1-Benzoxazine-2,4(1H)-dione and its N-methyl analogue react with alkylidenephosphoranes to give substituted quinolines and benzazepines as well as indanone and furan derivatives. Reaction mechanisms to explain the formation of products obtained are outlined. Georg Thieme Verlag Stuttgart.
Heterocyclic 8?-Systems, 16 - Elimination Reactions of 2-Alkoxy-3-hydroxyindolines
Beitzke, Bernhard,Schmidt, Richard R.
, p. 1726 - 1731 (2007/10/02)
Thermolysis of 2-ethoxy-3-hydroxyindolines 1a - f affords oxindoles 3a - f as main products and the corresponding 3-indolinones 2a - f as by-products.The reaction course via indole 2,3-oxide intermediates is discussed.For this reason rearrangement reactio
