The biosynthesis of folicanthine

O'Donovan, D. G.; Keogh, Myles F.

doi:10.1039/j39660001570

Cited by 12 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[46] That tryptophan and tryptamine are progenitor materials has been established by labeling studies. Radioactive calycanthine and folicanthine are procured from Calycanthus floridus fed with (AE )- [b-14 C]-tryptophan, [47,48] H]-tryptamine are both converted into chimonanthine in leaf-bearing shoots of Chimonanthus fragrans. [49] A oneelectron oxidation of a tryptamine gives rise to a possible mechanism by which linked cyclotryptamine units could arise biosynthetically.…”

Section: Biosynthesis Of Cyclotryptamine Alkaloidsmentioning

confidence: 99%

Total Synthesis of Complex Cyclotryptamine Alkaloids: Stereocontrolled Construction of Quaternary Carbon Stereocenters

2007

View full text Add to dashboard Cite

Our ability to access the more complex members of the cyclotryptamine family of alkaloids, and to exploit their disparate biological activities, is limited by the synthetic challenge posed by their oligomeric, polyindoline structures. A recurring structural theme within these molecules is the presence of multiple quaternary stereocenters in close proximity to one another. Over the last decade, we have developed a set of transformations that allow rapid access to polyindolines, a number of which exploit the ability of catalytic levels of palladium to orchestrate carbon-carbon bond formation with impressive levels of regio- and stereocontrol. This review tells the story behind the development of this toolbox of synthetic methods, and their validation through the total synthesis of a number of structurally complex cyclotryptamine alkaloids. It also highlights an aspect of asymmetric catalysis that has received little attention, the ability of catalytic asymmetric reactions to selectively elaborate complex, polyfunctional molecules.

show abstract

Section: Biosynthesis Of Cyclotryptamine Alkaloidsmentioning

confidence: 99%

Total Synthesis of Complex Cyclotryptamine Alkaloids: Stereocontrolled Construction of Quaternary Carbon Stereocenters

2007

View full text Add to dashboard Cite

show abstract

“…Die Rolle von Tryptophan und Tryptamin als Biosynthesevorstufen wurde durch Markierungsexperimente belegt. Nach Düngen von Calycanthus floridus mit (±)‐[β‐ 14 C]‐Tryptophan wurde 14 C‐markiertes Calycanthin und Folicanthin isoliert,47, 48 und in den laubtragenden Austrieben von Chimonanthus fragrans werden (±)‐[β‐ 14 C,2‐ 3 H]‐Tryptophan und [β‐ 14 C,2‐ 3 H]‐Tryptamin beide in Chimonanthin umgewandelt 49. Ausgangspunkt für einen möglichen Biosynthesemechanismus ist die Einelektronenoxidation von Tryptamin (Schema ) 50.…”

Section: Biosynthese Der Cyclotryptaminalkaloideunclassified

Totalsynthese komplexer Cyclotryptaminalkaloide: stereokontrollierter Aufbau quartärer Kohlenstoffstereozentren

Steven¹,

Overman²

2007

Angewandte Chemie

129

View full text Add to dashboard Cite

Die Cyclotryptamine sind eine Familie von Alkaloiden mit sehr unterschiedlichen biologischen Aktivitäten. Die komplexeren Mitglieder dieser Naturstoffklasse sind durch benachbarte quartäre Kohlenstoffzentren charakterisiert und wegen der schwierig aufzubauenden, oligomeren Polyindolinstruktur schwer zugänglich. In den letzten Jahren konnten wir eine Reihe von Methoden entwickeln, die einen einfachen Zugang zu Polyindolinen ermöglichen; einige dieser Methoden nutzen Palladiumkatalysatoren zum Aufbau von Kohlenstoff‐Kohlenstoff‐Bindungen mit beeindruckenden Regio‐ und Stereoselektivitäten. In diesem Aufsatz schildern wir die Entwicklung eines Repertoires an Synthesemethoden und deren Anwendung in den Totalsynthesen einiger strukturell komplexer Cyclotryptamine. Insbesondere zeigen wir auf, wie es gelingen kann, mithilfe asymmetrischer Katalysen komplexe, hochfunktionalisierte Moleküle aufzubauen.

show abstract

“…spectra of substituted cycl0hexanes,~0~ cis-decalins,lo5 perfluorocyclooctane 106 (a rigid or slowly interconverting distorted-crown structure is postulated), perfluorocyclobutane lo7 (very low-energy barrier to interconversion), cyclic trisulphides,lo8 N,O and S heterocyclic compo~nds,~0~ and 3,5,7-cyclo-octatrienone . lo Inversion a t a nitrogen atom has been studied in dihydroquinolines,llI benzylamines,ll2 and 2,2,3,3-tetrsmethylaziridine (17).l13 Solvent Ef€ects.-Dimethyl sulphoxide is enjoying increasing popularity as a solvent for hydroxyl containing compounds, because it suppresses the exchange rate and often allows the OH protons to participate in spin coupling.l14 However, this is not the case for alcohols with strongly electronegative substitutents (e.g., 2,2,2-tri~hloroefhanol).~~~ For ortho-nitroanilines, one observes a 0.5 p.p.m. downfield shift for the H-3 proton on changing from DMSO to CDC1, solvent,ll6 this is because the solute is normally intramolecularly hydrogen bonded, but the DMSO competes with the nitro-group for the hydrogen bonding site, resulting in rotation of both the amine and nitro-groups from the plane of the ring.…”

Section: Ormentioning

confidence: 99%

“…Homo-aromaticity has also been observed in anionic species. The reduction of cyclopropacyclo-octatriene ( 17) with potassium l9 gives the anion radical (18) with an e.s.r. spectrum consonant with the structure shown, (17) has also been converted into (18) by electrolytic reduction.20 Further reduction of the anion radical (18) with potassium 21 leads to the dianion (19) for which the homo-aromatic structure is proposed to account for its n.m.r.…”

mentioning

confidence: 99%

“…The reaction proceeds by migration of the acetoxonium ring by means of participation by a truns-acetoxy-substituent and goes via the 2,3-manno-, 3,4-altro-, and the 4,6-ido-acetoxonium ions [( 14), (15), and (16), respectively]; the latter finally hydrolysing to a mixture of idopyranose tetra-acetates (17) and (18). Similarly, the 1,2acetoxonium ion derived from D-XylOpyI'anOSe isomerises to D-arabhopyranose derivatives via 2,3-and 3,4-acetoxonium ions.…”

mentioning

confidence: 99%

See 1 more Smart Citation