The nucleophilic addition reaction of N-tosyl-4-oxo-4, 5, 6, 7-tetrahydroindole (12) with the lithium salt of 1-methoxyindole (5), followed by dehydration with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) gave the derivative of 2, 4'-bi-1H-indole (9) which provides a new concise synthetic method of an indole pigment of the slime mould, arcyriacyanin A. The compound was first demonstrated here to have unique inhibitory activity to a panel of human cancer cell lines and to inhibit protein kinase C and protein tyrosine kinase.
One-Pot Synthesis of 2-Substituted Indoles from 2-Aminobenzyl Phosphonium Salts. A Formal Total Synthesis of Arcyriacyanin A
作者:George A. Kraus、Haitao Guo
DOI:10.1021/ol801034x
日期:2008.7.17
The reaction of (2-aminobenzyl) triphenylphosphonium bromide with aromatic aldehydes or alpha,beta-unsaturated aldehydes under microwave-assisted conditions constitutes a newsynthesis of 2-substituted indoles in high yields (81-97%) in a one-potreaction. The adduct from indole-4-carboxaldehyde was an advanced intermediate in the synthesis of arcyriacyanin A.
AbstractArcyriacyanin A (1) has been synthesized by three different routes. In the first synthesis the bisbromomagnesium salt of 2,4′‐biindole (5) was treated with dibromomaleimide (6) to yield arcyriacyanin A (1). The second approach used an intramolecular Heck reaction for the cyclization of a 4‐(triflyloxy)arcyriarubin 8 to N‐methylarcyriacyanin A (2). Thirdly, compound 2 was obtained by a domino Heck reaction between 3‐bromo‐4‐[1‐(tert‐butoxycarbonyl)indol‐3‐yl]‐1‐methylmaleimide (9) and 4‐bromoindole (10). The N‐methyl derivative 2 could be transformed into arcyriacyanin A (1) by standard methods.