Visible-light-promoted [2+1] and [2+2] cycloaddition reactions of diazocarbonyls with
olefins have been developed, affording functionalized cyclopropanes and cyclobutanes,
respectively. In visible-light catalysis of Ir(ppy)3, a simple addition of Rh2(OAc)4 switches the regioselectivity from [2+1] to [2+2] cycloaddition with good reactivity
and high regioselectivity.
Key words
photocatalysis - Rh
2(OAc)
4
- cycloaddition - α-diazo compounds - switchable regioselectivity