Borane evolution and its application to organic synthesis using the phase-vanishing method. (13th April 2021)

• Record Type: Journal Article
• Authors: Soga, Nene; Yoshiki, Tomo; Sato, Aoi; Kawamoto, Takuji; Ryu, Ilhyong; Matsubara, Hiroshi
• Is Part Of: Tetrahedron letters. Volume 69(2021)
• Publication Date: 2021-04-13
• Subjects: Phase-vanishing method -- Fluorous solvent -- Gaseous reagents -- Borane -- Hydroboration; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2021.152977
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Borane was generated from NaBH4 and n Bu4 NBH4 using phase-vanishing (PV) method. The generated borane was directly used in the hydroboration of alkenes. Selective reduction of carboxylic acids with the generated borane was examined. Organoboranes generated by the PV method underwent Suzuki–Miyaura coupling. PV method is an alternative to using borane–THF or borane–Me2 S as borane source. Abstract: Although borane is a useful reagent, it is difficult to handle. In this study, borane was generated in situ from NaBH4 or n Bu4 NBH4 with several oxidants using a phase-vanishing (PV) method. The borane generated was directly reacted with alkenes, affording the desired alcohols in good yields after oxidation with H2 O2 under basic conditions. The selective reduction of carboxylic acids with the evolved borane was examined. The organoboranes generated by the PV method successfully underwent Suzuki–Miyaura coupling. Using this PV system, reactions with borane can be carried out easily and safely in a common test tube.