Synthesis
Phosphonium salt (2.2 mmol) was added to a cooled solution (- 78 ??C) of
Et3N
(4.44 g, 44 mmol) in di-n-butyl ether (20 mL). The reaction mixture was
stirred at -78 ??C for 5 h and then allowed to warm gradually to r.t.
The solvent was removed under vacuum and the residue was dissolved in
degassed EtOH (5 mL). After stirring for 15 min, the solid was filtered
off and dried to yield the desired phosphine, which can be further
purified by crystallization from EtOH. Butyldi-1-adamantylphosphine,
yield 90%.
31P NMR (C6D6)|?: 24.9. Mp 108-110??C. IR (KBr): 3425 (m, br),
2952 (s), 2847 (s), 2847 (s), 2675 (w), 1446 cm-1 (m). 1H NMR (250 MHz,
C6D6): |? = 0.96 (3 H, t, 3JH, H = 7.3 Hz, CH3), 1.35-2.03 (36 H, m,
adamantyl-30H, butyl-6H). 13C NMR (62 MHz, C6D6): |? = 41.3 (d, 2JC,P =
11.3 Hz, C-2), 37.4 (C-4), 36.1 (d, 1JC,P = 23.5 Hz, C-1), 33.9 (d,
1JC,P = 26.2 Hz, butyl-|á -CH2), 29.1 (d, 3JC,P = 7.6 Hz, C-3), 24.9 (d,
2JC,P = 13.1 Hz, butyl-|? -CH2), 17.1 (d, 3JC,P = 21.6 Hz, butyl-|? -CH2),
14.3 (butyl-CH3). MS (EI, 70 eV): m/z (%) = 358 (M+, 60), 135 (Ad+,
100).