Reaktive E=C(p-p)π-Systeme, XLIII [1] Darstellung und Charakterisierung P-Phosphino- oder P-Arsino-substituierter Fluorphosphaalkene des Typs R2E-P=C(F)NEt2 (R = Me, CF3, Me2N; E = P, As) / Reactive E=C(p-p)-π Systems XLIII [1] Synthesis and Characterization of P-Phosphino or P-Arsino Substituted Fluorophosphaalkenes of the Type R2E-P=C(F)NEt2 (R= Me, CF3, Me2N; E = P As)

Abstract

Abstract The easily accessible phosphaalkene HP=C(F)NEt2 (lb) reacts with halophosphanes or -arsanes R2EX (X = Cl, I) in the presence of NEt3 to give P-phosphino- or -P-arsino substituted fluorophosphaalkenes of the type RiE-P=C(F)NEti (2 - 6) in high yields (60 - 85 %) [R2E: (CF3)2P (2), Me2N(CF3)P (3), Me2P (4), (CF3)2As (5), Me2As (6)]. The analogous reaction of ib with CF3PI2 (molar ratio 1:2) unexpectedly leads to the triphosphetene Et2N - C=P-PCF3-PCF3 (7). The stability of compounds 2 - 6 as a function of R2E decreases from As to P and from CF3 to Me, respectively. Compounds 2 - 6 generally show the Z-configuration and have been characterized by thorough spectroscopic investigations (MS,IR; 1H, 19F, 11C, 31PNMR). A single crystal X-ray diffraction study of 2 proves the π-type interaction of the nitrogen lone pair with the P=C bond thus enhancing the stability of the system and the PP bond order