[​4+2] versus [​2+2] Homodimerization in P(V) Derivatives of 2,4-Disubstituted Phospholes

Table 5

³¹P and ⁷⁷Se NMR chemical shifts (ppm) (CDCl₃) and coupling constants of 6 and 7.

		6		7
Entry	R	δ (^31P)	δ (^77Se)	δ (^31P)	δ (^77Se)
1	Ph; (a)	39.4	-397; (d, = 733 Hz)	64.5	-385; (d, = 759 Hz)
2	Trimethylsilyl; (b)	52.0	-466; (d, = 716 Hz)	No dimer
3	t-Butyl; (c)	36.9	-430; (d, = 724 Hz)	No dimer