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

Table 3

³¹P NMR chemical shifts (ppm) (CDCl₃) of 4 and 5 (done in acetone-d₆).

Entry	R	1	4	5
1	Ph; (a)	11.3		71.2
2	Trimethylsilyl; (b)	31.9	66.1	No dimer
3	t-Butyl; (c)	1.4	51.7	No dimer
4	4-F-Ph; (d)	11.9	53.5	71.2