Beitraege zur Chemie des bors, 226: Funktionalisierung von Alkinylboranen-Umsetzung mit Nucleophilen

Article abstract of DOI:10.1016/0022-328X(94)05147-4

The synthesis of alkynylboranes RR'B-C<*>C-R" 1-3 and their reactions with various nucleophiles are described (R, R' = Me2N, Cl, alkyl; R" = Me, Ph).Although these compounds can be looked upon as inorganic Michael systems, nucleophiles such as alcohols, amines, amides and various carbon nucleophiles attack exclusively at the boron atom (analogous to a 1,2- attack).Thus, a nonvenient means of functionalization of alkynylboranes at the boron atom with preservation of the B-C<*>C moiety is described, and alkynylboranes with R,R' = Me2N, N(H)ⁱPr, pyr, OⁱPr, Me, Mes, C<*>C-SiMe3 were obtained in good yield and characterized by spectroscopic methods.The pathway for the reaction of (Me2N)2B-C<*>C-Ph with carbon nucleophiles to tris(alkyl)boranes has been elucidated.The implications both for the electronic properties and the chemical reactivity of alkynylboranes are discussed.Keywords: Alkynylboranes, Nucleophilic attack, Organoboron compounds, Inorganic Michael systems; Boron; Alkyne