- 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)
-
- Flame retardant polycyanurate thermosets from the cyanate esters of triphenylphosphine oxide
-
Three cyanate esters containing phosphorus are synthesized in good overall yields starting from bromoanisoles. Di- and tricyanates with meta configuration are most stable while para is less so. The para dicyanate ester isomer is particularly affected by water from the atmosphere. The meta dicyanate ester 2 has good thermal properties with glass transition at 268 °C and char yield of 65% in air at 600 °C. All three phosphorus-containing cyanate esters are low flammability in an open flame. They make highly combustible cyanate esters resins less flammable simply by blending. Mixing 10 wt% dicyanate ester 2 into bisphenol A or E dicyanate esters makes them rate V-0. Published 2018.? J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1100–1110.
- Davis, Matthew C.,Garrison, Michael D.,Ghiassi, Kamran B.,Groshens, Thomas J.,Redeker, Neil D.
-
p. 1100 - 1110
(2018/03/21)
-
- Organocatalyzed Reduction of Tertiary Phosphine Oxides
-
A novel selective catalytic reduction method of tertiary phosphine oxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1-5 mol% even at low temperature (70 C). Under the optimized conditions various phosphine oxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%. Furthermore, we have developed a one-pot reaction sequence for the preparation of valuable phosphinborane adducts. Simple addition of BH3THF subsequent to the reduction step gave the desired adducts in yields up to 99%.
- Schirmer, Marie-Luis,Jopp, Stefan,Holz, Jens,Spannenberg, Anke,Werner, Thomas
-
supporting information
p. 26 - 29
(2016/01/25)
-
- Synthesis of symmetrical and unsymmetrical functionalized arylphosphines from chlorophosphines and organozinc reagents
-
A stepwise procedure allowing the formation of symmetrical arylphosphines is described. It relies on the use of preformed functionalized aromatic organozinc reagents to perform arylations of chlorophosphines. Some preliminary results concerning the synthesis of unsymmetrical diarylphenylphosphines through sequential coupling of organozinc species with dichlorophenylphosphine are also reported. Georg Thieme Verlag Stuttgart.
- Le Gall, Erwan,Ben A?ssi, Karima,Lachaise, Isabelle,Troupel, Michel
-
p. 954 - 956
(2007/10/03)
-
