Darstellung und Charakterisierung einiger ω -Cyanalkyldiorganophosphane Preparation and Characterization of Some ω - Cyanoalkyldiorgano Phosphines

Abstract

Several routes for the preparation of ω-cyanoalkyldiorgano phosphines RR′P (CH2)nCHR″CN (R = CH3, C2H5, C3H7, i-C3H7, C4H9, i-C4H9, t -C4H9, C5H11, c-C5H9, c-C6H11 ; R′ = i-C3H7, t-C4H9, C6H5; R″ = H, Si(CH3)3; n = 1, 2, 3, 4) have been investigated: (1) reaction of lithium diorganophosphides with ω-chloroalkylnitriles, (2) quaternization of secondary phosphines with co-haloalkylnitriles followed by deprotonation of the resulting H -phosphonium halides with aqueous bases, (3) hydrophosphination of secondary phosphines with unsaturated nitriles, (4) reaction of trimethylsilyl phosphines with (y-chloroalkylnitriles followed by Me3SiCl-elimination, and (5) addition of acrylonitrile to trimethylsilyl phosphines. The reaction of 3-chloropropionitrile with trimethylsilyl phosphines leads to the formation of a mixture of the expected phosphine and the corresponding β-silylated derivative. A mechanistic interpretation of the last reaction is given. All new compounds were characterized by elemental analyses, IR and NMR spectra.

Die Darstellung sterisch anspruchsvoller Phosphinoester und ihre Verwendung zur Synthese von Rhodium(I)-und Rhodium(III)-Komplexen [1] / The Preparation of Sterically Demanding Phosphinoesters and their Use for the Synthesis of Rhodium(I) and Rhodium (III) Complexes

“…Bei unseren Untersuchungen zur Darstellung von Phosphinonitrilen konnten wir zeigen [8 ], daß sich die sehr einfach zugänglichen (Gl. (1)) Trimethylsilyldiorganophosphane in vielen Fällen als geeignete Edukte für den Austausch eines orga nisch gebundenen Chloratoms durch eine Phosphinogruppe erweisen.…”

“…Aus diesem Grunde wurde hier sofort auf die M e thode der Hydrophosphinierung [10] zurückge griffen, die in m ehreren Beispielen (8)(9)(10)(11)(12)(13)(14)(15)(16)(17) P-NMR-Spektrum beobachtet man bei -2 0 °C den AB-Teil ei nes ABX-Spinsystems (A, B = P und X = Rh), wobei die zwei D ubletts von D ubletts bei einer chemischen Verschiebung ö = 65,04 und 60,73 ppm auftreten. Wir nehm en an, daß das bei höherem Feld erscheinende Signal wegen des R ingbeitra ges, der auf die zusätzliche Koordination eines Carbonylsauerstoffatoms zurückzuführen ist [11], dem Phosphoratom des Chelatliganden entspricht.…”

“…-3 1 P-NMR (36,2 MHz,C6 D 6): (3 = 41,20 (d), /(R h P ) = 123,1 Hz. C 1 9 H 3 8 C10<;P2Rh (546,8) Ber. C 41,73 H 7,00% ,Gef.…”

Synthesis and Coordination Chemistry of Cyano-Substituted Phosphines

“…A similar approach was used for the synthesis of mono( -cyanoalkyl) phosphines with different chain length [31,32]. While the reaction of silylphosphines 13 with chloroacetonitrile is exothermic and completed within few minutes, for less reactive chlorobutyronitrile (n=3) rather prolonged heating of the reaction mixture is necessary.…”

“…Thus, alkylation of lithium phosphides by -chlorocarbonitriles results in a complex mixture of products (independently on the temperature, order of reagent addition and solvent), where the portion of the desired R2P(CH2)nCN is ca 10-20% [32].…”