Our group is working toward developing new technologies that reduce the environmental impact of many types of reactions in synthetic organic chemistry. One general approach being taken is to perform reactions that would normally require the dissolution of reactants and catalysts in organic solvents that now take place in aqueous media within the inner lipophilic cores of nanomicelles. We have found, for several important transition metal–mediated processes, that lower loadings of precious metal catalysts not only suffifice but can be used under far milder reaction conditions. In this protocol we illustrate this general approach to organic synthesis by describing in detail two chemical reactions: peptide synthesis and nitro-group reduction. The former was chosen because it represents not only an especially important type of bond formation found in both academic and industrial labs but also one that falls under the category of homogeneous catalysis. By contrast, Procedure 2 describes the conversion of a readily available, albeit potentially dangerous, nitro group into its especially valued corresponding primary amine derivative. This process uses carbonyl iron powder as a heterogeneous reagent, also under aqueous micellar conditions. Hence, these procedures document the potential for water to serve as the gross reaction medium, accommodating both homo- and heterogeneous catalysis. And, unlike traditional procedures of today in organic media, they satisfy several of the fundamental 12 Principles of Green Chemistry.
原文见PDF附件
