- Photocatalytic Arylation of P4 and PH3: Reaction Development Through Mechanistic Insight
-
Detailed 31P{1H} NMR spectroscopic investigations provide deeper insight into the complex, multi-step mechanisms involved in the recently reported photocatalytic arylation of white phosphorus (P4). Specifically, these studies have identified a number of previously unrecognized side products, which arise from an unexpected non-innocent behavior of the commonly employed terminal reductant Et3N. The different rate of formation of these products explains discrepancies in the performance of the two most effective catalysts, [Ir(dtbbpy)(ppy)2][PF6] (dtbbpy=4,4′-di-tert-butyl-2,2′-bipyridine) and 3DPAFIPN. Inspired by the observation of PH3 as a minor intermediate, we have developed the first catalytic procedure for the arylation of this key industrial compound. Similar to P4 arylation, this method affords valuable triarylphosphines or tetraarylphosphonium salts depending on the steric profile of the aryl substituents.
- Cammarata, Jose,Gschwind, Ruth M.,Lennert, Ulrich,Rothfelder, Robin,Scott, Daniel J.,Streitferdt, Verena,Wolf, Robert,Zeitler, Kirsten
-
supporting information
p. 24650 - 24658
(2021/10/14)
-
- Versatile Visible-Light-Driven Synthesis of Asymmetrical Phosphines and Phosphonium Salts
-
Asymmetrically substituted tertiary phosphines and quaternary phosphonium salts are used extensively in applications throughout industry and academia. Despite their significance, classical methods to synthesize such compounds often demand either harsh reaction conditions, prefunctionalization of starting materials, highly sensitive organometallic reagents, or expensive transition-metal catalysts. Mild, practical methods thus remain elusive, despite being of great current interest. Herein, we describe a visible-light-driven method to form these products from secondary and primary phosphines. Using an inexpensive organic photocatalyst and blue-light irradiation, arylphosphines can be both alkylated and arylated using commercially available organohalides. In addition, the same organocatalyst can be used to transform white phosphorus (P4) directly into symmetrical aryl phosphines and phosphonium salts in a single reaction step, which has previously only been possible using precious metal catalysis.
- Arockiam, Percia Beatrice,Lennert, Ulrich,Graf, Christina,Rothfelder, Robin,Scott, Daniel J.,Fischer, Tillmann G.,Zeitler, Kirsten,Wolf, Robert
-
supporting information
p. 16374 - 16382
(2020/11/03)
-
- Tetra-arylfluorophosphoranes
-
A number of novel tetra-arylfluorophosphoranes have been synthesised.The most stable form of these compounds is the ionic form PR4+F- (R=aryl) although various other forms have been shown to exist including a molecular monomer PR4F and a dimer PR4+PR4F2-.The i.r. spectra of the ionic forms reveal strong P+...F- interactions.The fluorides are prepared via the hydrogendifluorides PR4+HF2- which contain distorted HF2- ions.
- Brown, Stephen J.,Clark, James H.,Macquarrie, Duncan J.
-
p. 277 - 280
(2007/10/02)
-