Synthesis and Ring Expansion of Triflylated Cyclobutenyl MIDA Boronates

High Resolution Image Download MS PowerPoint Slide A synthetic method for regioselectively building borylated bis(triflyl)cyclobutenes from BMIDA alkynes and in situ formed 1,1-bis(triflyl)ethylene has been developed. In addition, the conversion of the so-prepared borylated cyclobutenes into BMIDA-substituted naphthyl triflones has been accomplished by simple thermal treatment without using any catalyst. A sequence capable of directly affording functionalized naphthalenes from alkynes in a one-pot manner was also possible. In this way, a divergent approach to offering otherwise difficult-to-prepare cyclobutenyl boronates and ((triflyl)naphthalen-1-yl)boranes from the same precursor by slight modification of the reaction conditions has been discovered.