Synthesis of functionalized potassium alkyl and alkenyltrifluoroborate salts via the hydroboration of functionalized terminal alkenes and alkynes with dicyclohexylborane and two groups reductive-alkylation
Boronic derivatives are valuable intermediates in synthetic chemistry and drug discovery programs. They are mainly used in metal-catalyzed Suzuki-Miyaura and Chan- Lam cross-coupling reactions to construct carbon-carbon and carbon-heteroatom bonds, respectively. In this study, we developed the first general route to functionalized potassium alkyl and alkenyltrifluoroborate salts using the hydroboration route with dicylohexylborane of functionalized terminal alkenes and alkynes, followed by a two group reductivealkylation. This method is mild, tolerant to a wide variety of functional groups and gives rapidly functionalized potassium alkyl and alkenyltrifluoroborate salts in good to excellent yields. Also, all starting materials and reagents are readily available and inexpensive. This makes functionalized alkyl and alkenyl boronic derivatives readily available for organic synthesis; especially, cross-coupling reactions, as well as for drug discovery programs.