Rh(II) catalysed intramolecular C–H insertion of diazo substrates in water: a simple and efficient approach to catalyst reuse

Water is an efficient solvent for the Rh2(OAc)4 catalysed intramolecular C–H insertion of a range of diazo substrates without competitive water insertion. Due to the high solubility and stability of the catalyst in water, the catalyst can be efficiently reused.