Synthesis of 3-stannyl and 3-silyl propargyl phosphanes and the formation of a phosphinoallene

Abstract

The group 14 chloropropargyls R3EC ≡ CCH2Cl (R3E = (n)Bu3Sn, Ph3Sn, Me2PhSi, (i)Pr3Si, (n)Pr3Si, (n)Bu3Si), obtained by a modified literature procedure, react with LiPPh2 to afford the novel propargyl phosphanes Ph2PCH2C ≡ CER3 in high yield, as viscous oils; (Me3Si)2PCH2C ≡ CSiPhMe2 is similarly obtained from LiP(SiMe3)2. In contrast, the reaction of PhC[triple bond, length as m-dash]CCH2MgCl with ClP(NEt2)2 fails to produce a comparable propargyl phosphane, but generates preferentially (>70%) the novel phosphinoallene (Et2N)2PC(Ph) = C = CH2, which is characterised spectroscopically, and through its reaction with HCl. The coordination chemistry of representative phosphanes is explored with respect to platinum and palladium for the first time.

η1:η2-P-Pyrazolylphosphaalkene Complexes of Ruthenium(0)

“…First described in 1985 [24], such systems remain relatively rare, though-with the exception of type E-all possible motifs have been realized, with P-metalla-(type A) and C-metalla-(type B) systems the most heavily studied. Recently, as part of an extended program investigating transition metal compounds featuring low-coordinate phosphacarbons with potential for conjugation [25][26][27][28], we have prepared and studied a range of ruthenaphosphaalkenyl complexes of the type [Ru{P=CH(SiMe2R)}Cl(CO)(PPh3)2] (R = Me 1a, Ph 1b, Tol 1c) [29,30]. These are prepared by hydroruthenation of phosphaalkynes R3SiC≡P, following from methodology developed initially by Hill and Jones for t BuC≡P and related systems [31][32][33], and superficially related to Nixon's independent reduction of [(Ph3P)2Pt(η 2 -P≡C t Bu)] with Schwartz's reagent [34].…”