Additions of PH3 to monosubstituted alkenes of the formula H2C=CH(CH2)x(CF2)yCF3:: Convenient, multigram syntheses of a family of partially fluorinated trialkylphosphines with modulated electronic properties and fluorous phase affinities

Reactions of PH3 and commercially available H2C=CHRf (R-f6/8/10 = (CF2)(5)CF3/(CF2)(7)CF3/(CF2)(9)CF3); give, in two-stage processes conducted with free radical initiators (AIBN, VAZO; 80-90 degrees C), the phosphines P(CH2CH2Rf)(3) (1-3; 63-75%). Analogous reactions with H2C=CHCH2Rf8 (7) and H2C=CHCH2CH2Rf8 (10) give P(CH2CH2CH2Rf8)(3) (4, 73%) and P(CH2CH2CH2CH2Rf8)(3) (5, 66%), in which the phosphorus is increasingly insulated from the electronegative R-f moiety. The alkenes 7 and 10 are prepared from Bu3SnCH2CH=CH2 and IRf8 (hv, CH2Cl2, 81%) or ICH2Rf8 (VAZO, refluxing CF3C6H5, 56%). The reaction of 1 and H2O2 gives O=P(CH2CH2Rf6)(3) (6, 88%), which can be reduced with HSiCl3 to 1. Partition coefficients (CF3C6F11/toluene, 27 degrees C) range from 98.8:1.2 (1, 4) through 98.9:1.1 (5) to >99.7: <0.3 (2, 3, 6). Crystals of 4 diffract poorly, but a packing motif that maximizes interactions between R-f segments is evident.