Useful procedures for fluorocyclization of tryptamine and tryptophol derivatives to 3a-fluoropyrrolo[2,3-b]indoles and 3a-fluorofuro[2,3-b]indoles

Totalsynthese von α‐ und β‐Amanitin

“…Hpi ist durch Persäure‐ oder Dimethyldioxiran‐(DMDO)‐Oxidation von Tryptophan zugänglich und wurde für die erste, von Perrin et al. beschriebene Totalsynthese von α‐Amanitin verwendet .…”

“…Hpi ist durch Persäure-oder Dimethyldioxiran-(DMDO)-Oxidation von Tryptophan [27,28] zugänglich und wurde für die erste, von Perrin et al beschriebene Totalsynthese von a-Amanitin verwendet. [2b] Bedauerlicherweise nutzt diese Methode der Hpi-Herstellung gefährliche Oxidationsmittel, was den Einsatz dieses Verfahrens für die Herstellung grçßerer Substanzmengen erheblich erschwert.…”

N-Fluoropyridinium Salt Electrophilic Fluorination for Preparing Alkyl Fluorides

“…As shown in Scheme 34, the intramolecular fluorocyclization of various 3-(2-aminoethyl) indole (tryptamine) derivatives 102 with I-2a was carried out, giving 103 in good to high yields. Importantly, this process was especially effective for the indoles bearing a free NH group [25].…”

Synthesis of 10b-fluorinated analogues of protubonine A and its 11a-epimer via fluorocyclisation of tryptophan-containing dipeptides

“…8 As a part of our studies on the design, synthesis and biological evaluation of fluorine-containing bioactive compounds, 9 we recently reported a versatile procedure for a fluorocyclisation reaction of tryptamines 5 with N-fluoro-2, 4,6-trimethylpyridinium triflate (7), obtaining the corresponding 3a-fluoropyrrolo[2, 3-b]indoles 6 (Scheme 1). 10 Since the replacement of the 10b-hydroxy group of 1 with a fluorine would generate a useful analogue for understanding the biochemical behaviour of 1, we envisaged application of our fluorocyclisation reaction to the synthesis of the 10b-fluorinated analogue 3 of 1. However, unfortunately, after we started our synthesis of 3, de Lera and co-workers reported that in actuality, protubonine A is represented by 2 and has a 3S,5aR,10bR,11aS configuration.…”