The regioselectivity of 1, 3-dipolar cycloaddition reactions between mesoionic compounds with singly-tethered substituents is examined. The results with propiolate dipolarophiles are compared with other singly and doubly-tethered examples according to a model using an asynchronous, concerted transition state. The isolation and reaction of a novel, nonaryl substituted mesoionic compound 7 is reported. A regiodirected synthesis starting with N-(2 ...
