Novel allyl boron compounds are readily synthesized, via rearrangement reactions between Lewis acidic B(C6F5)(3) and propargyl esters. These reactions proceed through an initial cyclization followed by ring-opening and concurrent C6F5-group migration. In the absence of disubstitution adjacent to the ester oxygen atom, an allyl boron migration rearrangement leads to formal 1,3-carboboration products. These allyl boron compounds act as allylation reagents with aldehydes introducing both a C-3-allyl fragment and a C6F5-unit as a single anti-diastereomer. In these reactions, (C6F5)(3) activates the alkynes, prompting the rearrangement processes and enabling installations of C6F5 and R-groups.