Synthese amino- und silylsubstituierter Triphosphane – Struktur des 1.1.3.3-Tetrakis(di-iso-propylamino)-2-trimethylsilyl- und des 1.1.3.3-Tetraphenyl-2-tri-iso-propylsilyl-triphosphans / Synthesis of Amino- and Silyl-Substituted Triphosphines – Structure of 1,1,3,3-Tetrakis(di-iso-propylamino)-2-trimethylsilyl- and 1,1,3,3-Tetraphenyl-2-tri-iso-propylsilyl-triphosphine

Abstract

A variety o f triphosphines [(Et2N )2 P]2PR 4 a -h , [('Pr2 N )2P]2PR 5 a -e and [Ph,P]-,PR 9 e -g [R = Cy (a), rBu (b), Mes (c), M e3Si (d), 'BuM e2Si (e), ThexM e2Si (f), 'Pr3Si (g), Äd"(h), H (i)] has been obtained by the reaction o f the dilithiated primary phosphines R PH 2 l a -h with 2 equiv. o f the chlorophosphines (Et2 N )2PCl 2, ('Pr2N )2PCl 3 or Ph2PCl 8 . M ethanolysis o f the trimethylsilyl substituted derivative [('Pr2 N )2 P]2P(SiM e3) 5d yields the hydrogen substituted triphosphine [('Pr2 N )2 P]2PH 5i. The lithiated diphosphine ('Pr2 N )2 P -P (S iM e 3)Li 6 reacts with the chlorophosphine 2 to give the unsymmetrically substituted triphosphine ('Pr2N )2 P -P (S iM e 3 )-P ( N E t2 ) 2 7d. The com pounds have been chracterized by their N M R and mass spectra. The structures o f 4d and 9g have been determined by X-ray diffraction, repre senting the first structures o f uncomplexed triphosphines.

Synthesis of Stable Potassium Phosphinophosphides and Reaction with Organosilyl Halides and Chlorophosphanes

“…Triphosphanes bearing larger substituents were found to exhibit bond angles in a range from 100.0°to 118.7°( single crystal; for comparison, Raman measurements revealed a P1−P2−P3 angle of 104.5°for the smallest triphosphane P 3 H 5(l) ). 54,55,75 The P1−P2−P3 angle of the herein-reported diphosphanes 7a [107.667( 7)°] and 7b [106.28(3)°] are within this previously reported range.…”

“…In the symmetrically substituted triphosphane 7a, the P1− P2 [2.2363(2) Å] and P1−P3 [2.2123(2) Å] bonds differ significantly in their lengths. Differing P−P lengths in symmetrical triphosphanes have been published previously, 55,74 and in the case of 7a, they can probably be attributed to the differing steric interactions with the Ter substituent at the P1 Differing P−P bond lengths can also be observed for the asymmetrically substituted triphos-phane 7b [P1−P2(iPr 2 ) = 2.2176(7) Å; P1−P3(Ph 2 ) = 2.2338(7) Å; ∑r cov (P−P) = 2.22 Å]. 70 In 7b, the isopropyl groups are disordered, which might influence the P−P distance determination.…”

“…Phosphinophosphides are potential synthetic precursors for the introduction of various substituents into diphosphanes. Lithium phosphinophosphides are relatively well-known species with synthetic applications as transfer reagents in transition-metal chemistry − or as building blocks for the synthesis of P-rich compounds. − These species can be accessed via the reaction of R 2 P–P­(TMS) 2 precursors with organolithium reagents, yielding R 2 P–P­(TMS)­Li­(L) x compounds [L = solvents such as tetrahydrofuran (THF)]. ,, Alternative syntheses involve the conversion of diphosphenes with lithium bases (Scheme ). , The reported lithium phosphinophosphide syntheses also yield significant amounts of side products such as symmetrization products, which drastically reduce the yield of the desired product species. ,,− …”