Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S3H6, Canada.
Chemistry. 2010 Jan 18;16(3):988-93. doi: 10.1002/chem.200902369.
By employing strategies based on frustrated Lewis pair chemistry, new routes to phosphino-phosphonium cations and zwitterions have been developed. B(C(6)F(5))(3) is shown to react with H(2) and P(2)tBu(4) to effect heterolytic hydrogen activation yielding the phosphino-phosphonium borate salt [(tBu(2)P)PHtBu(2)] [HB(C(6)F(5))(3)] (1). Alternatively, alkenylphosphino-phosphonium borate zwitterions are accessible by reaction of B(C(6)F(5))(3) and PhC[triple chemical bond]CH with P(2)Ph(4), P(4)Cy(4), or P(5)Ph(5) affording the species [(Ph(2)P)P(Ph)(2)C(Ph)=C(H)B(C(6)F(5))(3)] (2), [(P(3)Cy(3))P(Cy)C(Ph)=C(H)B(C(6)F(5))(3)] (3), and [(P(4)Ph(4))P(Ph)C(Ph)=C(H)B(C(6)F(5))(3)] (4). A related phosphino-phosphonium borate species-[(Ph(4)P(4))P(Ph)C(6)F(4)B(F)(C(6)F(5))(2)] (5) is also isolated from the thermolysis of B(C(6)F(5))(3) and P(5)Ph(5).
通过采用基于受阻路易斯对化学的策略，开发了新的磷膦阳离子和两性离子的路线。B(C(6)F(5))(3) 被证明可与 H(2) 和 P(2)tBu(4) 反应，通过异裂氢活化生成磷膦硼酸盐盐[(tBu(2)P)PHtBu(2)] [HB(C(6)F(5))(3)] (1)。或者，通过 B(C(6)F(5))(3) 和 PhC[三重键]CH 与 P(2)Ph(4)、P(4)Cy(4)或 P(5)Ph(5)反应，可获得烯基膦膦硼酸盐两性离子，得到[(Ph(2)P)P(Ph)(2)C(Ph)=C(H)B(C(6)F(5))(3)] (2)、[(P(3)Cy(3))P(Cy)C(Ph)=C(H)B(C(6)F(5))(3)] (3)和[(P(4)Ph(4))P(Ph)C(Ph)=C(H)B(C(6)F(5))(3)] (4)。从 B(C(6)F(5))(3)和 P(5)Ph(5)的热解中还分离出了一种相关的磷膦硼酸盐物种[(Ph(4)P(4))P(Ph)C(6)F(4)B(F)(C(6)F(5))(2)] (5)。
