Organocatalysed Enantioselective Reactions

Over the last few years several groups have focussed on the use of organic catalysts to promote C-C bond forming reactions.  In the USA, the groups of MacMillan, List (both Europeans!) have predominated, whereas in Europe, the work of Jorgensen at Aarhus, Denmark has been well received.  These reactions are of great industrial interest since they build up highly functionlised molecules using simple procedures in which the catalyst can easily be reused.  Jorgensen has recently published on the inverse – demand Hetero-Diels-Alder reaction (Juhl K et al, Angew Chem Int Edn, 2003, 42, 1498).  The cycloaddition of aldehydes to unsaturated carbonyls gives the dihydropyran, which is the presence of silica yields ring opened products.  The silica also helps catalyst turnover.