107368-93-4Relevant academic research and scientific papers
Asymmetric hydrovinylation of vinylindoles. A facile route to cyclopenta[g]indole natural products (+)-cis-trikentrin A and (+)-cis-trikentrin B
Liu, Wang,Lim, Hwan Jung,Rajanbabu
, p. 5496 - 5499 (2012/05/20)
Vinylindoles undergo Ni(II)-catalyzed asymmetric hydrovinylation under very mild conditions (-78 °C, 1 atm ethylene, 4 mol % catalyst) to give the corresponding 2-but-3-enyl derivatives in excellent yields and enantioselectivities. Hydroboration of the alkene and oxidation to an acid, followed by Friedel-Crafts annulation, gives an indole-annulated cyclopentanone that is a suitable precursor for the syntheses of cis-trikentrins and all known herbindoles. For example, the cyclopentanone from 4-ethyl-7-vinylindole is converted into (+)-cis-trikentin A in four steps (Wittig reaction, alkene isomerization, diastereoselective hydrogenation, and nitrogen deprotection). The previous synthesis of this molecule from (S)-(-)-malic acid involved more than 20 steps and a preparative HPLC separation of diastereomeric intermediates.
Total syntheses of (±)-cis-trikentrin A and (±)-cis- trikentrin B via electrocyclic ring closures of 2,3-divinylpyrrolines
Huntley, Raymond J.,Funk, Raymond L.
, p. 3403 - 3406 (2007/10/03)
A convergent and versatile strategy for the diastereoselective syntheses of (±)-cis-trikentrin A and B in 10 and 12 steps, respectively, from commercially available N-BOC-2-pyrrolidinone is described. The key step in each of the total syntheses is the construction of the central benzene ring via a facile 6π-electrocyclic ring closure of an appropriately substituted 2,3-divinylpyrroline, in turn, readily available by a Stille coupling reaction.
Total synthesis of (±)-herbindole B and (±)-cis-trikentrin B
Jackson, Stephen K.,Banfield, Scott C.,Kerr, Michael A.
, p. 1215 - 1218 (2007/10/03)
(Chemical Equation Presented) Herbindole B and cis-trikentrin B are naturally occurring indoles having the unusual and synthetically challenging pattern of carbon substitution at the 4-7 and 5-7 positions, respectively, with no substitution at the 1-3 positions. The total syntheses of these polyalkylated indoles have been achieved in 19 and 12 steps, respectively. The synthesis of herbindole B relies on two iterations of a quinine monoimine Diels-Alder reaction, while cis-trikentrin B uses a single cycloaddition of a suitable quinone monoimine. Indolization of the adducts provides suitably substituted benzopyrrole nuclei for elaboration to the natural products.
Enantioselective total synthesis of cis-trikentrin B
Lee, Mase,Ikeda, Izumi,Kawabe, Tsuyoshi,Mori, Sayaka,Kanematsu, Ken
, p. 3406 - 3416 (2007/10/03)
Natural cis-trikentrin B was synthesized enantioselectively using, as key steps, an intramolecular Diels-Alder reaction of an allenic dienamide followed by aromatization to construct an indole ring and cleavage of bicyclo[2.2.1]heptene to launch a cis-dimethylcyclopentane ring. Diels-Alder adducts 9 and 10 were elaborated to provide allenic dienamide 25, and its intramolecular Diels-Alder reaction proceeded smoothly. Aromatization to an indole ring and stereoselective cleavage of the bicyclo[2.2.1]heptene ring were performed successfully. Introduction of an (E)-butenyl group via addition of propylmagnesium bromide and subsequent anti elimination of water gave natural cis-trikentrin B.
Preparation of alkyl-substituted indoles in the benzene portion. Part 11. Total synthesis of (6R,8S)-herbindole A, (6R,8S)-herbindole B, (6R,8S)-herbindole C (6R,8S)-cis-trikentrin A, (6R,8S)-cis-trikentrin B, (6R,8R)-trans-trikentrin B, and (6R,8R)-iso-t
Muratake,Mikawa,Seino,Natsume
, p. 854 - 864 (2007/10/02)
The key intermediate, (3R,5S)-3,5-dimethyl-1-cyclopentenylmethanol (13) for chiral syntheses of herbindoles and trikentrins, was prepared from the known Diels-Alder adduct 12. Employing pertinent methodologies developed in the previous model study (preced
Total synthesis of (6R,8S)-cis-trikentrin B, (6R,8R)-trans-trikentrin B, and (6R,8R)-iso-trans-trikentrin B. determination of the absolute structures of the natural trikentrins B
Muratake, Hideaki,Seino, Takako,Natsume, Mitsutaka
, p. 4815 - 4818 (2007/10/02)
The absolute structures of cis-trikentrin B, trans-trikentrin B, and iso-trans-trikentrin B were established to be 1, 2, and 3 by synthesizing the titled trikentrins 1,18b and 25 in an enantiospecific manner from a chirality-defined Diels-Alder adduct 7.
SYNTHESIS OF (+/-)- AND (-)-CIS-TRIKENTRIN A, (+/-)- AND (-)-TRANS-TRIKENTRIN A, (+/-)-CIS-TRIKENTRIN B, (+/-)-TRANS-TRIKENTRIN B, AND (+/-)-ISO-TRANS-TRIKENTRIN B
Muratake, Hideaki,Watanabe, Makoto,Goto, Koichi,Natsume, Mitsutaka
, p. 4179 - 4192 (2007/10/02)
Synthesis of the titled indole alkaloids from a marine source was accomplished according to the general scheme in Chart 1.The key steps were preparation of suitably substituted β-hydroxyl carbonyl compounds (8b) from 7b, and the subsequent indole cyclizat
The Total Synthesis of (+/-)-cis-Trikentrin B via Allene Intramolecular Cycloaddition
Yasokouchi, Takanori,Kanematsu, Ken
, p. 6559 - 6562 (2007/10/02)
The first total synthesis of (+/-)-cis-trikentrin B (1) based on a new indole synthesis via the intramolecular Diels-Alder reaction of 1,2,3-trisubstituted allenic dienamide (8) is described.
