Keith Jones

Aryl radical cyclisation onto pyrroles: a divergent synthesis of spiropyrrolidinyloxindoles and pyrroloquinolines

Abstract The regiochemistry of cyclisation of an aryl radical on to a pyrrole is shown to depend on the N -substituent of the pyrrole. Changing this substituent allows the selective synthesis of either the spiropyrrolidinyloxindole or the pyrrolo[3,2- c ]quinoline skeleton.

Aryl radical cyclisation onto pyrroles

Abstract The intramolecular cyclisation of aryl radicals onto a pyrrole is studied. The cyclisation allows the synthesis of either the spiropyrrolidinyloxindole or the pyrrolo[3,2- c ]quinoline skeleton depending on the nature of the protecting group at the N -pyrrole atom. The regiochemistry of the cyclisation is not affected by the substituents on the benzene ring. Some limitations on the utility of tosylmethylisocyanide in pyrrole synthesis are also reported.

Glowing jellyfish, luminescence and a molecule called coelenterazine

Luminescence has assumed an important role in analytical biochemistry and molecular biology as an extremely sensitive method for determining the concentration of specific ions and molecules. The luminescent system of the jellyfish Aequorea victoria consists of the photoprotein aequorin, which contains the molecule coelenterazine as a prosthetic group and shows considerable potential in this area.

Annulation of indole via indole radicals: addition of the 2-indolyl radical to aromatic rings

Abstract The reactions of the radicals derived from indoles 4 are described leading to a short synthesis of fused [1,2-a]indoles via radical addition to the benzene ring followed by rearomatisation whilst one example undergoes an unusual radical translocation/addition reaction.

A Suzuki coupling approach to bufadienolides

Abstract A high yielding route to bufadienolide type steroids using a novel Suzuki coupling reaction between a range of steroid vinyl triflates and 2-pyrone-5-boronate 11 is presented.

Reaction of indolin-2-ones with cerium(IV) ammonium nitrate

Abstract The reaction of indolin-2-ones with CAN is studied. When the reaction is carried out in an alcohol as solvent, 3-alkoxyindolin-2-ones are obtained in very good yields. If a non-nucleophilic solvent is used (THF, acetonitrile) 3-nitroxy derivatives are isolated. If the aromatic ring bears an electron-donating group, reactions are accompanied by aromatic ring nitration.

A tandem radical approach to the ABCE-rings of the Aspidosperma and Strychnos alkaloids

Reaction of indole 19 via the derived aryl radical ngives the tetracycle 20 in 43% yield. This compound contains the ABCE-rings nof both Aspidosperma and Strychnos alkaloids.

Synthetic studies on morphine-based analgesics: an approach to angular substitution in 4a-aryldecahydroisoquinolines via dienolate chemistry

Abstract The reaction of the dienolate generated from 9 using lithium hexamethyldisilazide with a range of alkyl halides has been explored and the regioselectivity and stereochemistry of the adducts determined. Reaction of the dienolate with an oxaziridine gave hydroxylation at the C-8a position as found in some potent morphine-like analgesics.

Biomimetic ligands for transition metals: catechol-containing peptides

The tetrapeptide ligands 6a and 6b containing a catechol moiety have been synthesised and their metal binding with Fe(III), Mn(III) and Cu(II) has been studied using fluorescence spectroscopy.

Intermolecular reactions of indol-2-yl radicals: a new route to 2-substituted indoles

The generation of indol-2-yl radicals and their addition to a variety of radical acceptors to prepare 2-substituted indoles is presented.