The cover picture, provided by Peter Allen and Bruce Lipshutz (UCSB), illustrates an asymmetric conjugate addition of an arylboronic acid to an enone. The key contribution focuses on a nonracemic (R-BINAP)-ligated rhodium catalyst that is covalently tethered to the ubiquinol-derived platform PQS, thereby forming “PQS-BINAP-Rh”. This new species spontaneously dissolves in water to form micelles that function as nanoreactors in which the 1,4-additions take place. These reactions occur at room temperature within the lipophilic cores of these nanoparticles to afford the expected high levels of ees. When complete, the product is extracted from the water directly from the reaction vessel with small amounts of a single organic solvent. Virtually none (i.e., ppb) of the rhodium is lost to the product upon extraction. The water can be recycled without its removal from the reaction vessel. This enabling technology, therefore, allows for valued asymmetric homogeneous catalysis to be run in the absence of organic solvents, with no investment in energy in the form of heating or cooling, with in-flask recycling of both the aqueous medium and a costly catalyst, and with no contamination of the desired product by a transition metal. This methodology is illustrated in the communication by Lipshutz and co-workers on pages 3175–3179.
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