Cycloisomerization of olefins in water.

Preparative reactions that occur efficiently under dilute, buffered, aqueous conditions in the presence of biomolecules find application in ligation, peptide synthesis, polynucleotide synthesis and sequencing. However, the identification of functional groups or reagents that are mutually reactive with one another, but unreactive with biopolymers and water, is challenging. Here we show that cobalt catalysts will react with alkenes under dilute, aqueous, buffered conditions and promote efficient cycloisomerization and formal Friedel-Crafts reactions. We find the constraining conditions of biorthogonal chemistry to be beneficial for reaction efficiency as we obtain superior conversion at low catalyst concentration and maintain competent rates in dilute conditions. Efficiency at high dilution in the presence of buffer and nucleobases suggests that these conditions may find broad application. .