Convenient synthesis of chiral tryptophan derivatives using Negishi cross-coupling was written by Tanaka, Minoru;Hikawa, Hidemasa;Yokoyama, Yuusaku. And the article was included in Tetrahedron in 2011.Category: indole-building-block This article mentions the following:
A facile synthetic procedure for chiral tryptophan derivatives using Negishi cross-coupling reaction of serine-derived iodoalanine with 3-haloindole is described. The best result was obtained when the reaction of N-tosyl-3-bromoindole with N-Cbz-iodoalanine Me ester (Cbz = benzyloxycarbonyl) was carried out by the combination of Pd2(dba)3 and sterically hindered ferrocenyl ligand Q-PHOS. This reaction condition not only gave the desired tryptophan derivative as high as 76% yield, but also suppressed the formation of undesired products, the dehalogenated indole and the homodimer of indole, which were difficult to sep. This reaction was extended to the synthesis of various tryptophan derivatives having substituents on the benzene ring. The characteristic of this reaction is the practical biomimetic synthesis of chiral tryptophan derivatives in one-step. In the experiment, the researchers used many compounds, for example, 4-Nitroindole (cas: 4769-97-5Category: indole-building-block).
4-Nitroindole (cas: 4769-97-5) belongs to indole derivatives. Indole is an important structural motif of various drugs, therapeutic leads besides its prevalence in numerous natural products, agrochemicals, perfumery, and dyes.Indole was synthesized in moderate yield via an o-naphthoquinone catalyzed tandem cross-coupling of substituted aniline and benzylamine under aerobic oxidation conditions.Category: indole-building-block
Referemce:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles