Total Syntheses of (+)‐T988 B and (+)‐T988 C through the AgNTf₂‐Mediated Coupling of Bromopyrroloindoline with Indole

Abstract

The total syntheses of (+ +)-T988 Ba nd (+ +)-T988 Cw ere accomplished in 19 and 18 steps, respectively,i n2 0.2 %o verall yield. The indole segment was regioselectively introduced at the sterically hindered C10b position through ad iastereoselective bromocyclization reaction and as ubsequent AgNTf 2 -mediated Friedel-Crafts reaction. The dithiodioxopiperazine moiety was efficiently constructed throughaone-pot radical-mediated CÀHb romination/dehydrobromination procedure on the dioxopiperazine ring.

AgNTf2-Mediated Allylation with Allylsilanes at C3a-Position of Hexahydropyrroloindoles: Application to Total Syntheses of Amauromine Alkaloids

“…Recently, it has been discovered that AgNTf 2 is a highly effective activating agent of haloindolenines and halopyrroloindolines to promote their Friedel–Crafts type arylation with electron-rich aromatic compounds . Its efficiency and utility were demonstrated by our total syntheses of dimeric indole alkaloids, (+)-haplophytine and (+)-T988B…”

Biosynthesis of pyrroloindoline-containing natural products

“…27). The rst member of this class is pestalazine B (223), which has unusual D-residues in the diketopiperazine framework. It was discovered from the secondary metabolites of the plant pathogenic fungus Pestalotiopsis theae.…”

Synthetic Studies toward Dimeric Indole Alkaloids Based on Convergent Synthetic Strategy

“…Herein, I report the first total synthesis of haplophytine 22) via a silver salt-mediated coupling reaction between two indole units and its second-generation synthesis 23) through a convergent synthetic route. Furthermore, we applied the silver bis(trifluoromethanesulfonyl) imide (AgNTf 2 )-mediated coupling reaction discovered in the synthesis of haplophytine to the introduction of aryl moiety into pyrroloindoline 24) and total syntheses of T988s. 25)…”