Homo- and heterodehydrocoupling of phosphines mediated by alkali metal catalysts

Abstract

Catalytic chemistry that involves the activation and transformation of main group substrates is relatively undeveloped and current examples are generally mediated by expensive transition metal species. Herein, we describe the use of inexpensive and readily available t BuOK as a catalyst for P–P and P–E (E = O, S, or N) bond formation. Catalytic quantities of t BuOK in the presence of imine, azobenzene hydrogen acceptors, or a stoichiometric amount of t BuOK with hydrazobenzene, allow efficient homodehydrocoupling of phosphines under mild conditions (e.g. 25 °C and < 5 min). Further studies demonstrate that the hydrogen acceptors play an intimate mechanistic role. We also show that our t BuOK catalysed methodology is general for the heterodehydrocoupling of phosphines with alcohols, thiols and amines to generate a range of potentially useful products containing P–O, P–S, or P–N bonds.

Bismuth Amides Mediate Facile and Highly Selective Pn–Pn Radical‐Coupling Reactions (Pn=N, P, As)

“…Inf.). In contrast, polar mechanisms have been discussed for most main group compounds in phosphane dehydrocoupling [25a–c, 26, 28, 29] . Notably, the only other main group species that has been reported for the challenging dehydropouling of dialkylphosphanes has also been suggested to operate via polar reaction pathways [26, 29] .…”

Bismutamide als einfache Vermittler hochselektiver Pn−Pn‐Radikal‐Kupplungsreaktionen (Pn=N, P, As)

“…Inf.). Im Gegensatz dazu wurden für die meisten von Hauptgruppenverbindungen vermittelten Phosphan‐Dehydrokupplungen polare Reaktionsmechanismen diskutiert [25a–c, 26, 28, 29] . Auch für das einzige literaturbekannte Beispiel einer Hauptgruppenverbindung, welche die bis dato herausfordernde Dehydrokupplung eines Dialkylphosphans ermöglicht, wurden polare Reaktionspfade vorgeschlagen [26, 29] .…”

Leveraging Exchange Kinetics for the Synthesis of Atomically Precise Porous Catalysts

“…[33] In this synthesis, the uncoordinated phosphines were preserved during polymerization due to the selection of Zr 4 + as the metal ion for SBU construction; the hard acid Zr 4 + does not strongly coordinate with phosphines, which are soft bases according to hard-soft acid-base (HSAB) theory. [34] Post-synthetic metalation of the lattice-bound phosphines with either Ru 2 + or Rh 2 + provided materials that were applied to asymmetric group-transfer reactions. [33]…”