Facile synthesis of cyclo-(P4tBu3)-containing oligo- and pnictaphosphanes.

The cyclo-(P4tBu3) synthon [Li{cyclo-(P4tBu3)}(thf)(tmeda)] (1) (thf = tetrahydrofuran, tmeda = N,N,N',N'-tetramethylethane-1,2-diamine) is readily accessible in a one-pot synthesis from P4 and LitBu. The use of 1 as a cyclo-(P4tBu3) building block enables the rational synthesis of cyclo-(P4tBu3)-containing oligophosphanes, namely {cyclo-(P4tBu3)}2 (2), {cyclo-(P4tBu3)}2PtBu (3) and {cyclo-(P4tBu3)}2CH2 (4), C3v-symmetric pnictaphosphanes E{cyclo-(P4tBu3)}3 (E = Bi, Sb, As; 5-7) as well as AsCl{cyclo-(P4tBu3)}2 (8). Compounds 5 and 6 represent the first neutral homoleptic bismuthane and stibane that contain only bonds to phosphorus. All new compounds were isolated in moderate to good yields and fully characterised. The 31P{1H} NMR spectral data of 1, 2, 4, and 8 have been determined by automated line-shape analysis.