Synthesis of Cycloalkanoindoles by an Unusual DAST‐Triggered Rearrangement Reaction.

Abstract

Reaction. -Treatment of symmetrical and unsymmetrical bisindolyl derivatives with DAST results in formation of cycloalkanoindoles which are of biological interest. Surprisingly, irrespective of the substitution pattern the same mixture of products is obtained. Possible mechanism is discussed. -(GIANNINI*, G.; MARZI, M.; MORETTI, G. P.; PENCO, S.; TINTI, M. O.; PESCI, S.; LAZZARO, F.; DE ANGELIS, F.; Eur.

RuCl3·3H2O Catalyzed Reactions: Facile Synthesis of Bis(indolyl)methanes under Mild Conditions

“…During the past decade a large number of natural products containing bis(indolyl)methanes [ 9 ] and bis(indolyl)ethanes [ 10 ] have been isolated from marine sources. Consequently, a number of synthetic methods for the preparation of bis(indolyl)alkane derivatives by reacting indoles with various aldehydes and ketones in the presence of either a Lewis acid [ 11 ] or a protic acid [ 12 , 13 , 14 ], metal salts, such as In(OTf) 3 [ 15 ], Dy(OTf) 3 [ 16 , 17 ], Ln(OTf) 3 [ 18 ], and CeCl 3 ·7H 2 O [ 19 , 20 ], and molecular iodine [ 21 , 22 ], as well as solid acidic catalysts [ 23 , 24 , 25 ], such as clays and Zeolites, have been reported in the literature. In addition, it has been reported that the reactions of indoles with various aldehydes were carried out in a protic solvent in the absence of any other catalyst to afford bis(indolyl)methanes [ 26 ].…”

Synthesis and Biological Evaluation of a γ-Cyclodextrin-based Formulation of the Anticancer Agent 5,6,11,12,17,18,23,24- Octahydrocyclododeca[1,2-b:4,5-b’:7,8-b’’:10,11-b’’’]tetraindole (CTet)

“…These actions depend on an autolysis product of 3-indolylmethyl glucosinolate (glucobrassicin), namely indole-3-carbinol ( I3C , Figure 1 ) [ 4 , 5 ], and the resulting indole oligomers produced in the acidic environment of the stomach: 3,3’-diindolylmethane ( DIM ) [ 4 , 5 ], indolo[3,2- b ]carbazole ( ICZ ) [ 6 , 7 ], the linear trimer LTr [ 6 , 8 , 9 ], the cyclic trimer CTr [ 6 , 8 , 10 ], and the cyclic tetramer CTet [ 11 , 12 ] ( Figure 1 ) [ 2 ]. The current interest of pharmacologists and medicinal chemists in this topic has resulted in several reports which disclosed synthetic analogues of I3C [ 13 , 14 , 15 ], DIM [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ], and CTr [ 32 ] possessing anticancer properties.…”