Synthesis and reactivity of P-acetylenic (silylamino)phosphines

The title compounds, (Me3Si)(2)NP(CdropCR)(2) (1: R = SiMe3; 2: R = n-Bu; 3: R = CH2OCH3), (Me3Si)(2)NP(Ph)CdropCSiMe(3) (4), and (Me3Si)(2)NP(R)CdropCCH(2)OCH(3) (5: R = i-Pr; 6: R = CH2SiMe3; 7: R = n-Bu) were obtained from the reactions of C-lithiated acetylenes LiCdropCR with either mono- or dichloro substituted (silylamino)phosphines. Similar reactions involving HCdropCMgCl gave the parent P-ethynyl derivatives, (Me3Si)(2)NP(R)CdropCH (12: R = CH2SiMe3; 13: R = Ph). Deprotonation-substitution at the terminal C-H group of 12 readily afforded the Me3Si derivative, (Me3Si)(2)NP(CH2SiMe3)CdropCSiMe(3) (14). Oxidative bromination of 7 gave the P-bromophosphoranimine, Me3SiN=P(n-Bu)(CdropCCH(2)OCH(3))Br (8). The P-trifluoroethoxy analogs, Me3SiN=P(CH2SiMe3)(CdropCCH(2)OCH(3))OCH2CF3 (10) and Me3SiN=P(CdropCSiMe(3))(2)OCH2CF3 (11), were prepared from phosphines 6 and 1, respectively, via bromination followed by substitution with CF3CH2OH-Et3N. The diphosphinoacetylenes, (Me3Si)(2)N(R)P-CdropC-P(R)N(SiMe3)(2) (15: R = n-Pr; 16: R = CH2SiMe3), were obtained by treating appropriate P-chloro(silylamino)phosphines with the carbide reagent LiCdropCMgCl. All of these P-acetylenic derivatives were thermally stable, distillable liquids that were characterized by NMR spectroscopy. (C) 2002 Elsevier Science B.V. All rights reserved.