Reactivity of stable neopentyl-Pd intermediates in the absence of nucleophile

In the absence of any trapping agent, stable neopentyl-Pd intermediates can terminate a catalytic cycle by undergoing a regioselective C–H activation, leading to various spiro or fused cyclopropane derivatives in a straightforward manner. If the neopentyl-Pd intermediate contains a heteroatom at a suitable position, C–H activation does not occur and stable palladacycles are isolated.