Over the last 8 years, our laboratory has developed the concept of iminium catalysis, a mode of LUMO-lowering activation that has enabled the invention of a large number of enantioselective organocatalytic transformations including Diels-Alder cycloadditions, Friedel-Crafts alkylations, Mukaiyama-Michael additions, hydrogenations, and heteroconjugate additions.1 Central to the utility of this t...

Two new ligand systems related to the previously described DOTTADs have been generated in a simple one step reaction. The first, trans-DOTTADs, were formed by Vilsmeier formylation (followed by cyclisation and N-demethylation) of 2,6-dimethyl-3,5-pyrazine-dicarboxylic acid, to give the novel bis-pyridinopyrazine dialdehyde ligands. The corresponding pyrazine diester, reacted similarly to an int...

Simple haloaldehydes, including enolisable aldehydes, were found to be suitable for the formation of cyclic products by cascade (domino) condensation, cyclisation, dipolar cycloaddition chemistry. This multi-component reaction approach to heterocyclic compounds was explored by using hydroxylamine, a selection of aldehydes, and a selection of activated dipolarophiles. Initial condensation gives ...

The influence of N-substituents and chain length on the mode and rate of intramolecular reaction of ortho-quinone amines is reviewed. These reactions have been the subject of a series of studies over the last decade using a combination of pulse radiolysis, enzyme oximetry and preparative chemistry. Alternative reactions are cyclisation, spirocyclisation and para-quinomethane formation. The obse...

Methylation of phenyl 1,2-isopropy~idene-~-~-xy~ofuranose 3'-phosphate increases the rate of intramolecular cyclisation by a factor of over lo5. This confirms previous estimates of the effect of protonation on the reactivity of phosphate diesters towards a neighbouring hydroxy group, which depend on the correct assignment of kinetically equivalent mechanisms, and makes available reliable data o...

Di-, tri- and tetra-substituted oxetane derivatives with combinations of ester, amide, nitrile, aryl, sulfone and phosphonate substituents are prepared as fragments or building blocks for drug discovery. The synthesis of these novel oxetane functional groups, in new chemical space, is achieved via rhodium-catalysed O-H insertion and C-C bond forming cyclisation.

Benzo[c]cinnolines, thieno[3,2-c]cinnolines, pyrido[3,2-c]cinnolines and the previously undescribed quinoxalino[6,7-c]cinnoline ring system are conveniently prepared by a short synthetic route comprised of Suzuki coupling, base-catalysed cyclisation and deoxygenation. The use of tandem borylation-Suzuki coupling further extends the scope of this process to include highly substituted benzo[c]cin...

One-pot synthesis of highly substituted norbornadienes/norbornenes via gold-catalysed dehydrative cyclisation of alkynyldienols, followed by intermolecular [4 + 2] cycloaddition of in situ generated cyclopentadiene and activated alkynes/alkenes is described. The precursors, alkynyldienols, are obtained via sequential Sonogashira cross-coupling of 3-bromoenals, alkyne addition and reduction. Yie...

Re-investigation of the 1H-NMR spectrum reported for 15-bromo-4-oxa-2,9diaza-1(2,4)-pyrimidine-3(1,3)-benzenacyclononaphane (2) prepared via a Mitsunobumediated macroether cyclisation led to a proposed structural isomer (3). The title compound (3) was prepared via a two-step protocol and assigned using 1H, 13C-NMR and LC-MS.