Reduction of indigo: Simple syntheses of 3-acetoxy-, 1-acetyl-2.3-dihydro-, 3-acetoxy-3′-acetyl-, 3-acetoxy-1,3′-diacetyl-2,2′-bisindoles, and 2,2′-bisindole

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部Indigo was converted to 2,2′-bisindole by the direct reduction with zinc in acetic acid and acetic anhydride under argon or hydrogen atmosphere. Reduction with tin and iron afforded 3-acetoxy-2,2′-bisindole predominantly. Useful building blocks such as 1-acetyl-2,3-dihydro-, 3-acetoxy-3′-acetyl-, and 3-acetoxy-1,3′-diacetyl-2,2′-bisindoles were also produced depending on metal and reaction conditions

Simple synthesisi of 2-2\u27-bisindole from indigo and its application for the syntheses of indole[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H9dione and -5-(6H9one derivatives

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学

Short step synthesis of an antibiotic, 6-cyano-5-methoxy-12-methylindolo[2,3-a]carbazole

金沢大学大学院自然科学研究科生理活性物質科学For evaluating the effectiveness of organic synthesis, both intellectual property factor (IPF) and application potential factor (APF) are proposed. As a representative example, a highly effective synthetic method with IPF value of 53.8 and APF value of 100 has been established starting from indigo directing toward an antibiotic, 6-cyano-5-methoxy-12-methylindolo[2,3-a]carbazole, using only conventional reagents without using any protecting groups. © 2004 The Japan Institute of Heterocyclic Chemistry All rights reserved

The first syntheses of antiviral, cytotoxic 6-cyano-5-methoxy- and-12-methyundolo[2,3-a]carbazoles, and related indolo[2,3-a]carbazoles from indigo

金沢大学大学院自然科学研究科生理活性物質科学The first simple total syntheses of 6-cyano-5-methoxy- (1a) and -12-methylindolo[2,3-a]carbazolc (1b) are attained from indigo (2) in only five and six steps, respectively. Preparations of 5-hydroxy- (13), 5-bromoindolo[2,3-a]carbazole (14), and a novel spiro compound (7) are also included