Ring-Opening Reactions of Nonactivated Aziridines Catalyzed by Tris(pentafluorophenyl)borane

Abstract

The ring-opening reactions of nonactivated aziridines with amine nucleophiles are efficiently catalyzed by tris(pentafluorophenyl)borane leading to derivatives of trans-1,2-diamines in high yields. A mechanistic investigation of the reaction suggests that in situ formed [(C(6)F(5))(3)B(OH(2))].H(2)O catalyzes the opening through a Brønsted acid manifold.

Highly Sensitive NH3 Detection Based on Organic Field-Effect Transistors with Tris(pentafluorophenyl)borane as Receptor

“…15 TPFB is frequently used as a strongly Lewis acidic co-catalyst in numerous reactions, such as dehydration, 16 Friedel-Crafts reactions, 17 ring-opening reactions, 18 and syndiospecific living polymerization. 19 Here, TPFB was chosen as the NH3 receptor additive to the OFET semiconductors due to the strong interaction between boron atoms and nitrogen atoms 20 and the known vacuum sublimability of TPFB.…”

Structural Revision of the Ring-Opened Product in the ZnCl2-Catalyzed Reactions of 1-Benzyl-2-phenylaziridine with Thiols

“…3 Recently Yudin et al 5 studied the tris(pentafluorophenyl)borane-caytalyzed ring-opening reaction of aziridines with nitrogen or sulfur nucleophiles and reported the exclusive production of the so-called Hou's product, 2-benzylamino-2-phenyl phenyl sulfide, when 1 was treated with thiophenol. The same structure that was given in Hou's report was also given as the reaction product in their case because of identical spectral data.…”

Three‐Membered Heterocycles. Structure and Reactivity

“…In what may be one of the biggest catalyst sleepers of the century, the commercially available tris(pentafluorophenyl) borane [163] has escaped the niche of specialized polymerization catalysis and now finds application in various other useful synthetic transformations, including the ring opening of aziridines with simple amines (Table 2.12, entry 1). Interestingly, the active catalytic species involves a water-borane complex [164]. Other novel protocols for this reaction include ceric ammonium nitrate (CAN) in acetonitrile [165] and tributyl phosphite in an organic/aqueous medium [166].…”

“…For example, cyclohexene imine (118) engages in conjugate addition onto methyl acrylate under solvent-free conditions (Scheme 2.28, route a), although two equivalents of the Michael acceptor is needed [164]. The same aziridine undergoes smooth palladiumcatalyzed allylation with prenyl acetate, whereby the electrophile is captured at the more substituted terminus (route b), although this regiochemistry is substratedependent [189].…”