Stoichiometric reaction of B(C6F5)(3) with 1,6-enynes is shown to proceed via initial cyclopropanation and formal 1,1-carboboration. Depending on the substitution on the alkene moiety, subsequent ring-opening of the cyclopropane affords either cyclopentane or cydohexane derivatives in which the C6F5 and B(C6F5)(2) adopt a 1,4-positioning. Mechanistically, this transformation involves pi-activation of the alkyne moiety, which triggers cydopropanation, followed by carboboration. Both the cydopropanation and subsequent ring-opening are shown to be stereospecific. Both cyclopropanation and 1,4-carboborated products were employed as Lewis acid components in frustrated Lewis pair activation of H-2 and CO2.