Mesoionic compounds have proven to be valuable intermediates in organic chemistry from both physical and synthetic perspectives. These substances contain a masked 1,3-dipole within their framework and are therefore willing participants in 1,3-dipolar cycloadditions. Our interest in the chemistry of mesoionic dipoles stems from studies in our laboratory dealing with the rhodium(II)-catalyzed reactions of α-diazo carbonyl compounds in the presence of various heteroatoms. The isomünchnone class of mesoionics is easily generated from the Rh(II)-catalyzed reaction of α-diazo imides and readily undergoes cycloaddition with both electron-rich and electron-deficient dipolarophiles. This article compiles our findings in the general area of cascade reactions of isomünchnones together with relevant work from other laboratories.