Table 1.

Experimental (δ _exp) and calculated (δ _cal) ³¹P NMR chemical shifts of compounds 5, B, 6 and 7.

	5	B	6	7
δ exp/ppm	−273[a]	945[b]	1124[a]	−166[a]
δ cal/ppm	−242	1046	1221	−111

[a] Recorded in thf with C₆D₆ capillary at room temperature. [b] Recorded in CD₂Cl₂ at −20 °C.18