Double Annulative Cascade of Tryptophan-Containing Peptides Triggered by Selectfluor

Abstract

A common dearomative strategy toward the kapakahines B/F and chaetominine natural products is reported. The proposed biomimetic strategy generates the tetracyclic α-carboline core in a single step, featuring a selectfluor-mediated dearomatization of preactivated N-Phth-Trp-Xaa-OR dipeptides at the C-terminus. The pivotal cascade includes a double annulation and the formation of three carbon-heteroatom bonds while gaining, for the first time, some insight on the diastereoselectivity outcome during the formation of the α-carboline fragment.

Advancements in Aminofluorination of Alkenes and Alkynes: Convenient Access to β‐Fluoroamines

“…However, the use of Selectfluor instead of FP‐T300 gave low yields in fluorination cyclization of tryptophan derivatives. This strategy was also used for the synthesis of a fluorinated α‐carboline fragment 24…”

Amination/Cyclization Cascade by Acid-Catalyzed Activation of Indolenine for the One-Pot Synthesis of Phaitanthrin E

“…Herranz demonstrated the use of nitrile protonation of tryptophan-derived α-amino nitrile 6 in the synthesis of tetracyclic heterocycle 7 (Scheme a) via a cascade sequence proceeding through intramolecular amination at C-2 of the indole ring followed by intramolecular cyclization at the nitrogen atom of the indole ring . Recently, Roche developed an elegant double annulative cascade reaction of tryptophan-containing peptide 8 initiated by fluorine-mediated dearomatization (Scheme b) . This cascade sequence is efficient in building the stereochemically dense tetracyclic α-carboline 9 .…”

Synthesis of Phaitanthrin E and Tryptanthrin through Amination/Cyclization Cascade

“…In 2004, Herranz reported the the synthesis of tetracyclic heterocycle initiated by nitrile protonation of tryptophan‐derived α ‐amino nitrile, which cascade sequence proceeded through intramolecular C(2) selective amination of indole ring, followed by intramolecular cyclization at nitrogen atom of indole ring . Roche developed a double annulative cascade reaction of tryptophan‐containing peptide triggered by the fluorine‐mediated dearomatization of indoles ( Scheme ,b ) . This elegant cascade sequence is efficient to build the stereochemically dense tetracyclic α ‐carboline.…”