Insertion of Carbon Fragments into P(III)-N Bonds
reduced pressure, and the residue obtained was washed with
n-hexane (3 × 5 mL) and then dissolved in a mixture of CH2Cl2-
n-hexane (2:1) and kept at -15 °C for 2 days to give colorless
crystals of the products.
Preparation of Ph2P(O)CH2N(CH2)3NCH2P(O)Ph2 (10). A
mixture of bis(diphenylphosphino)ethylenediamine (0.20 g, 0.44
mmol) and paraformaldehyde (0.028 g, 0.88 mmol) in 7 mL of
toluene was heated under reflux conditions for 4 h. The solution
was then cooled to room temperature, solvent was removed under
reduced pressure, and the residue obtained was washed with hexane
(4 × 3 mL) and redissolved in a mixture of CH2Cl2-hexane (2:1)
to give the crystalline product of 10. Yield: 55% (0.130 g, 0.26
mmol). Mp: 132-134 °C. Anal. Calcd for C29H30N2O2P2: C, 69.59;
H, 6.04; N, 5.60. Found: C, 69.32; H, 6.01; N, 5.33. IR (KBr disk;
MeN(CH2P(O)Ph2)2 (4). Yield: 79% (0.182 g, 0.40 mmol).
Mp: 149-152 °C. Anal. Calcd for C27H27NO2P2: C, 70.58; H,
5.92; N, 3.05. Found: C, 69.17; H, 5.96; N, 3.04. IR (KBr disk;
cm-1): νPO 1189 s. 1H NMR (CD2Cl2): δ 2.62 (s, CH3, 3H), 3.63
2
(d, PCH2N, 4H, JPH ) 6 Hz), 7.20-7.95 (m, phenyl, 10H). 31P-
{1H} NMR (CD2Cl2): δ 29.8 (s). MS (HRMS): m/z 459.5.
EtN(CH2P(O)Ph2)2 (5). Yield: 73% (0.167 g, 0.35 mmol).
Mp: 148-152 °C. Anal. Calcd for C28H29NO2P2: C, 71.03; H,
6.17; N, 2.96. Found: C, 70.48; H, 6.15; N, 3.19. IR (KBr disk;
1
cm-1): νPO 1171 s. H NMR (CDCl3): δ 2.87 (s, CH2, 4H), 3.44
2
(d, PCH2N, 4H, JPH ) 7.19 Hz), 3.59 (s, CH2, 2H), 7.26-7.89
(m, phenyl, 20H). 31P{1H} NMR (CDCl3): δ 28.3 (s).
General Procedure for Preparation of Ph2P(O)CH(R)NHPh
(R ) Ph, OC4H3 (Furfuryl), C6H4OH-o). A mixture of Ph2PN-
(H)Ph (0.400 g, 1.44 mmol) and 1 equiv of aldehyde RCHO (R )
nPr, Ph, OC4H3, C6H4OH-o) was stirred at room temperature for
12 h. The resultant slurry was subjected to vacuum to remove any
volatiles, and the residue obtained was washed with n-hexane (3
× 5 mL) and crystallized in a mixture of CH2Cl2-n-hexane (2:1)
at 0 °C to give analytically pure products.
cm-1): νPO 1189 s. 1H NMR (CDCl3): δ 0.91 (t, CH3, 3H, 3JHH
)
6.95 Hz), 3.06 (q, CH2, 2H, 3JHH ) 6.93 Hz), 3.69 (d, PCH2N, 4H,
2JPH ) 5.86 Hz), 7.20-7.90 (m, phenyl, 10H). 31P{1H} NMR
(CDCl3): δ 29.5 (s).
nPrN(CH2P(O)Ph2)2 (6). Yield: 73% (0.167 g, 0.34 mmol).
Mp: 154-156 °C. Anal. Calcd for C29H35NO2P2: C, 71.45; H,
6.41; N, 2.87. Found: C, 70.81; H, 6.25; N, 2.43. IR (KBr disk;
cm-1): νPO 1178 s. 1H NMR (CDCl3): δ 0.95 (t, CH3, 3H, 3JHH
)
3
Ph2P(O)CH(Ph)N(H)Ph (11). Yield: 81% (0.451 g, 1.17 mmol).
Mp: 197-200 °C (dec). Anal. Calcd for C25H22NOP: C, 78.31;
H, 5.78; N, 3.65. Found: C, 78.01; H, 5.65; N, 3.17. IR (KBr disk;
cm-1): νNH 3387 s, νPO 1177 vs. 1H NMR (CDCl3): δ 5.39 (br m,
NH and CH, NH-D2O exchangeable, 2H), 6.58-7.92 (m, phenyl,
20H). 31P{1H} NMR (CDCl3): δ 32.7 (s). MS (FAB): 384 (m/z +
1).
Ph2P(O)CH(OC4H3)N(H)Ph (12). Yield: 67% (0.360 g, 0.96
mmol). Mp: 202-205 °C. Anal. Calcd for C23H20NO2P: C, 73.98;
H, 5.39; N, 3.75. Found: C, 73.05; H, 5.53; N, 3.40. IR (KBr disk;
cm-1): νNH 3372 s, νPO 1184 vs. 1H NMR (CDCl3): δ 4.95 (br m,
NH, D2O exchangeable, 1H), 5.34 (m, CH, 1H), 6.16-7.88 (m,
phenyl and furfuryl, 18H). 31P{1H} NMR (CDCl3): δ 30.3 (s). MS
(FAB): 374 (m/z + H).
7.25 Hz), 1.67 (sextet, CH2, 2H, JHH ) 7.25 Hz), 3.30 (t, CH2,
2H, 3JHH ) 7.25 Hz), 4.08 (d, PCH2N, 4H, 2JPH ) 5.85 Hz), 7.75-
8.20 (m, phenyl, 10H). 31P{1H} NMR (CDCl3): δ 29.1 (s).
iPrN(CH2P(O)Ph2)2 (7). Yield: 67% (0.152 g, 0.31 mmol).
Mp: 150-154 °C. Anal. Calcd for C29H35NO2P2: C, 71.45; H,
6.41; N, 2.87. Found: C, 70.81; H, 6.25; N, 2.73. IR (KBr disk;
cm-1): νPO 1183 s. 1H NMR (CDCl3): δ 0.83 (d, CH3, 6H, 3JHH
)
2
7.25 Hz), 2.31 (m, CH, 1H), 3.66 (d, PCH2N, 4H, JPH ) 6.18
Hz), 7.75-8.20 (m, phenyl, 10H). 31P{1H} NMR (CDCl3): δ 30.0
(s).
nBuN(CH2P(O)Ph2)2 (8). Yield: 75% (0.165 g, 0.33 mmol).
Mp: 178-180 °C. Anal. Calcd for C30H37NO2P2: C, 71.84; H, 6.63;
N, 2.79. Found: C, 72.16; H, 6.81; N, 2.51. IR (KBr disk; cm-1):
1
3
νPO 1190 s. H NMR (CDCl3): δ 0.72 (t, CH3, 3H, JHH ) 7.32
3
Ph2P(O)CH(C6H4OH-o)N(H)Ph (13). Yield: 89% (0.510 g,
1.28 mmol). Mp: 144-148 °C. Anal. Calcd for C25H22NO2P: C,
75.18; H, 5.55; N, 3.51. Found: C, 74.82; H, 5.32; N, 3.26. IR
Hz), 0.99 (sextet, CH2, 2H, JHH ) 7.5 Hz), 1.25 (m, CH2, 2H),
3
2
2.97 (t, CH2, 2H, JHH ) 7.14 Hz), 3.72 (d, PCH2N, 4H, JPH
)
5.5 Hz), 7.30-7.80 (m, phenyl, 10H). 31P{1H} NMR (CDCl3): δ
29.2 (s).
1
(KBr disk; cm-1): νOH 3390 br s, νNH 3220 s, νPO 1150 vs. H
The reactions of aminophosphines RN(H)PPh2 (R ) Et, nPr, and
nBu) with paraformaldehyde also gave compounds 5, 6, and 8. The
typical procedure is as follows: A solution of RN(H)PPh2 (1.5
mmol) and paraformaldehyde (1.50 mmol) in toluene (7 mL) was
heated to reflux for 5 h. The reaction mixture was cooled to room
temperature, and the solvent was removed under reduced pressure
to give a white residue which was redissolved in a mixture of CH2-
Cl2-n-hexane (2:1) and cooled to -10 °C for 2 days to give
analytically pure samples of 5, 6, and 8 in 70% (0.165 g, 0.31
mmol), 68% (0.247 g, 0.51 mmol), and 66% (0.248 g, 0.50 mmol)
yields, respectively.
NMR (CDCl3): δ 4.83 (br s, NH, D2O exchangeable), 5.46 (dd,
2
3
CH, 1H, JPH ) 12.0 Hz, JHH ) 3.0 Hz), 6.58-7.86 (m, phenyl,
19H). 31P{1H} NMR (CDCl3): δ 37.9 (s).
General Procedure for the Reaction of nPrN(PPh2) with
RCHO (R ) nPr, Ph, OC4H3, C6H4OH-o). A mixture of Ph2PN-
(nPr)PPh2 (0.400 g, 0.94 mmol) and 2 equiv of aldehyde RCHO
(R ) nPr, Ph, OC4H3, C6H4OH-o) was stirred at room temperature
for 24 h. The resultant slurry was subjected to vacuum to remove
any volatiles, and the residue obtained was washed with n-hexane
(3 × 5 mL) and crystallized in a mixture of CH2Cl2-n-hexane (2:
1) at 0 °C to give analytically pure products.
Ph2P(O)CH(OH)CH2CH2CH3 (14). Yield: 41% (0.210 g, 0.77
mmol). Mp: 116-118 °C. Anal. Calcd for C16H19O2P: C, 70.06;
H, 6.98. Found: C, 70.67; H, 6.87. IR (KBr disk; cm-1): νOH 3207
Preparation of Ph2P(O)CH2N(C2H4)2NCH2P(O)Ph2 (9). To a
solution of bis(diphenylphosphino)piperazine (0.20 g, 0.44 mmol)
in 7 mL of toluene was added paraformaldehyde (0.028 g, 0.88
mmol), heated under reflux conditions for 5 h. The solution was
then cooled to room temperature, the solvent was removed under
reduced pressure, and the residue washed with n-hexane (3 × 5
mL) and redissolved in a mixture of CH2Cl2-n-hexane (3:1) to
give the analytically pure product of 9. Yield: 73% (0.160 g, 0.31
mmol). Mp: 238-240 °C (dec). Anal. Calcd for C30H32N2O2P2:
C, 70.03; H, 6.27; N, 5.44. Found: C, 69.48; H, 6.15; N, 5.48. IR
(KBr disk; cm-1): νPO 1184 vs. 1H NMR (CDCl3): δ 2.57 (s, CH2,
4H), 3.19 (d, PCH2N, 2H, 2JPH ) 6.96 Hz), 7.41-7.82 (m, phenyl,
10H). 31P{1H} NMR (CDCl3): δ 27.2 (s).
1
3
s, νPO 1179 vs. H NMR (CDCl3): δ 0.85 (t, CH3, 3H, JHH
)
6.32 Hz), 1.38 (m, CH2, 2H), 1.65 (m, CH2, 2H), 1.73 (br s, OH,
D2O exchangeable, 1H), 4.41 (d, CH, 2H, 2JPH ) 10.32 Hz), 7.43-
7.89 (m, phenyl, 10H). 31P{1H} NMR (CDCl3): δ 31.3 (s).
The compound 14 is also obtained by the treatment of Ph2PN-
(H)Ph (0.400 g, 1.44 mmol) with butyraldehyde (0.104 g, 1.44
mmol) at room temperature. Yield: 89% (0.350 g, 1.28 mmol).
Ph2P(O)CH(OH)Ph (15). Yield: 42% (0.240 g, 0.78 mmol).
Mp: 164-166 °C (dec). Anal. Calcd for C18H17O2P: C, 74.01; H,
5.56. Found: C, 73.66; H, 5.29. IR (KBr disk; cm-1): νOH 3388 s,
Inorganic Chemistry, Vol. 42, No. 4, 2003 1279