Rhodium carboxylate catalyzed aromatic addition reactions of a range of diazoketones bearing methoxy-substituted aryl rings have been explored. While the existence of norcaradiene-cycloheptatriene equilibria in related compounds is well established, the aromatic addition products in this study display more complex dynamic equilibria due to conjugation with the methoxy group; the experimental evidence for this is discussed in detail. In the azulenone products 21-26 derived from p-methoxy-substituted diazoketones 14-16, the diastereomers interconvert via a spiro intermediate 39. A related mechanistic process in the azulenones 43-46 derived from the o-methoxy-substituted diazoketones 17, 18 interconverts regioisomers, explaining the conflicting reports for the regioselectivity of the cyclization of diazoketone 1. With the m-methoxy-substituted diazoketone 19, involvement of the methoxy group through a different pathway results in fragmentation of the azulenone to form the tetralone 47. With the azulenones 21-26 exclusive trapping of the norcaradiene associated with the less thermodynamically stable diastereomers in a cycloadduct with N-phenylmaleimide is observed. Due to the presence of the activating methoxy substituent on the aromatic ring, the aromatic addition reactions of the diazoketones studied were not very sensitive to the nature of the rhodium catalyst.

Two chiral copper(II) bis(oxazoline) complexes have been immobilized on silica via electrostatic interactions using a remarkably straightforward procedure. The immobilized catalysts were tested in a standard Diels-Alder reaction and gave surprising results. Where the immobilized Cu((S,S)-phenyl-box)(OTf) 2 catalyst was used, the predominant enantiomer formed was the opposite of that produced using the same catalyst in a homogeneous reaction. This is a startling result given that the only difference is the electrostatic immobilization of the catalyst on amorphous silica. The activity of the catalyst in a hetero Diels-Alder reaction was also tested. This catalyst was also recycled, successfully maintaining a similar activity to the homogeneous analogue through a number of cycles.

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Highly diastereoselective rhodium@) acetate-catalysed intramolecular addition of a-diazo ketones to aromatic rings to form the azulenones 3 has been achieved; the norcaradiene form of 3 undergoes efficient stereospecific cycloaddition with phenyltriazolinedione, in either a stepwise or a tandem process, leading to the pentacyclic systems 4 as a single diastereomer in each case.