1. Academic Validation
  2. Divergent Synthesis of Methylisatoid and Tryptanthrin Derivatives by Ph3P-I2-Mediated Reaction of Isatins with and without Alcohols

Divergent Synthesis of Methylisatoid and Tryptanthrin Derivatives by Ph3P-I2-Mediated Reaction of Isatins with and without Alcohols

  • J Org Chem. 2020 Dec 4;85(23):15743-15751. doi: 10.1021/acs.joc.0c02403.
Mookda Pattarawarapan 1 2 Nittaya Wiriya 1 Surat Hongsibsong 3 Wong Phakhodee 1 2
Affiliations

Affiliations

  • 1 Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
  • 2 Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand.
  • 3 School of Health Science Research, Research Institute for Health Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Abstract

A novel phosphonium-mediated reaction of isatins is described. In the presence of alcohol, the reaction proceeds to furnish C-12 modified tryptanthrin derivatives. Without alcohol, self-dimerization of isatins gives rise to tryptanthrin and its analogs. This divergent and step-economic approach provides a facile access to diverse indoloquinazoline structures including the natural Alkaloids, methylisatoid and cephalanthrin B, in high yields from simple precursors under mild and metal-free reaction conditions.

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