A R T I C L E S
Belser et al.
ether in n-pentane, gave 86% yield of thiol 11 (2.30 g). Mp: 92-93
°C. [R]2D0 +125.8 (c 0.93, CHCl3). Rf ) 0.36 (n-pentane/diethyl ether,
([M - BArF]+, 22), 738 (24), 540 (18), 474 (17), 395 (22), 317 (42),
286 (53), 255 (26), 241 (46), 210 (100), 183 (30), 103 (37), 89 (26),
77 (40), 68 (58), 55 (30), 39 (38). Anal. Calcd for C79H71NOBF24P2-
RhS: C, 55.36; H, 4.18; N, 0.82; O, 0.93. Found: C, 55.25; H, 4.12;
N, 0.81; O, 1.02.
1
1:1). H NMR (500.1 MHz, CD2Cl2, 295 K): δ 1.27 (sb, 12 H, CH2),
3
1.37 (t, JH,H ) 7.6 Hz, 1 H, SH), 1.53 (mc, 2 H, CH2), 1.60 (quin,
3JH,H ) 7.3 Hz, 2 H, CH2CH2SH), 2.09 (t, 3JH,H ) 7.7 Hz, 2 H, COCH2),
3
2.52 (dt, JH,H ) 7.3 Hz, 7.6 Hz, 2 H, CH2SH), 2.87 (mc, 1 H, PCH),
Thiol 18. 1-Ethyl-3-(3′-dimethylaminopropyl)carbodiimide hydro-
chloride (0.91 g, 4.77 mmol) and N-hydroxybenzotriazole (0.64 g, 4.77
mmol) were added to a solution of 11-mercaptoundecanoic acid (1.00
g, 4.70 mmol) in freshly distilled CH2Cl2 (100 mL) at 0 °C. After 5
min, (3R,4R)-3,4-bis(diphenylphosphorothioyl)pyrrolidine (2.00 g, 3.97
mmol) and triethylamine (1.80 mL, 12.8 mmol) were added, and the
reaction mixture was stirred for 6 h at 23 °C. The resulting solution
was washed with a saturated NH4Cl solution (100 mL) and water (100
mL). The organic phase was dried over MgSO4, filtered, and concen-
trated under reduced pressure. Purification of the crude material by
flash chromatography, eluting with 30% diethyl ether in n-pentane, gave
80% yield of thiol 18 (2.24 g). Mp: 62-64 °C. [R]2D0 +26.3 (c 0.83,
CHCl3). Rf ) 0.26 (n-pentane/diethyl ether, 1:2). 1H NMR (500.1 MHz,
CDCl3, 295 K): δ 1.16-1.29 (m, 10 H, CH2), 1.33 (t, J ) 7.6 Hz, 1
H, SH), 1.31-1.39 (m, 2 H, CH2), 1.48 (quinb, J ) 7.0 Hz, 2 H, CH2),
1.59 (quin, J ) 7.4 Hz, 2 H, CH2CH2SH), 1.93 (mc, 2 H, COCH2),
2.51 (mc, J ) 7.1 Hz, 7.6 Hz, 2 H, CH2SH), 3.55-3.64 (m, 1 H, PCH),
3.74-3.83 (m, 2 H, NCH2), 3.84-3.93 (m, 1 H, PCH), 3.96-4.10 (m,
2 H, NCH2), 7.21-7.28 (m, 4 H, CHPh), 7.36-7.53 (m, 8 H, CHPh),
7.60-7.66 (m, 2 H, CHPh), 7.71-7.76 (m, 2 H, CHPh), 7.79-7.87 (m,
4 H, CHPh). 13C{1H} NMR (125.8 MHz, CDCl3, 295 K): δ 24.9 (CH2),
25.0 (CH2), 28.7 (CH2), 29.4 (CH2), 29.6 (CH2), 29.7 (CH2), 29.7 (CH2),
29.8 (CH2), 34.4 (CH2), 34.7 (CH2), 38.7 (d, JC,P ) 54 Hz, PCH), 39.9
(d, JC,P ) 54 Hz, PCH), 48.1 (s, NCH2), 48.4 (s, NCH2), 129.1-129.3
3
2.94 (mc, 1 H, PCH), 3.34 (t, JH,H ) 11.9 Hz, 1 H, NCH2), 3.67 (t,
3JH,H ) 13.0 Hz, 1 H, NCH2), 3.90 (mc, 1 H, NCH2), 3.94 (mc, 1 H,
NCH2), 7.13-7.19 (m, 4 H, CHPh), 7.21-7.28 (m, 4 H, CHPh), 7.32-
7.45 (m, 12 H, CHPh). 13C{1H} NMR (125.8 MHz, CD2Cl2, 295 K): δ
24.7 (CH2), 24.9 (CH2), 28.5 (CH2), 29.1 (CH2), 29.5 (CH2), 29.5 (CH2),
31.0 (CH2), 31.0 (CH2), 34.2 (CH2), 34.8 (CH2), 37.3 (mc, PCH), 39.2
(mc, PCH), 47.9 (mc, NCH2), 48.8 (mc, NCH2), 128.6-129.6 (m,
CHPh-ortho
para), 133.5-133.7 (m, CHPh-meta), 135.9-136.8 (m,
and
C
Ph-ipso), 171.5 (CO).31P{1H} NMR (202.5 MHz, CD2Cl2, 295 K): δ
-12.5 (d, JP,P ) 8 Hz), -12.3 (d, JP,P ) 8 Hz). IR (KBr): ν (cm-1
)
3
3
3053w, 2926s, 2847s, 1643s, 1432s, 1332m, 1270w, 1246w, 1214m,
1197w, 1090m, 1068m, 1025m, 999m, 739s, 702s, 646m, 543w, 513m,
482m. MS (EI): m/z (rel int %) 639 (M+, 16), 530 (13), 371 (11), 268
(13), 262 (64), 236 (7), 185 (47), 108 (16), 68 (100), 55 (12). Anal.
Calcd for C39H47NOP2S: C, 73.21; H, 7.40; N, 2.19; Found: C, 73.12;
H, 7.36; N, 2.15.
Synthesis of Rhodium Complex 12. [Rh(COD)Cl]2 (0.89 g, 1.80
11,12
mmol) and TlBArF
(3.84 g, 3.60 mmol) were dissolved in freshly
distilled CH2Cl2 (50 mL) and stirred for 1 h at 23 °C. The precipitated
TlCl was filtered off and washed with freshly distilled CH2Cl2 (10 mL).
To the resulting orange solution was added at 0 °C slowly a solution
of thiol 11 (2.30 g, 3.60 mmol) in freshly distilled CH2Cl2 (20 mL)
and stirred for 1 h at 23 °C. The solvent was concentrated at reduced
pressure. The residue was purified by chromatography on silica gel,
eluting with CH2Cl2 to provide the desired orange complex 12 (3.18
g) in 52% yield. Mp: 114-116 °C. [R]2D0 -25.8 (c 0.24, CHCl3). Rf )
0.39 (CH2Cl2). 1H NMR (500.1 MHz, CD2Cl2, 295 K): δ 1.19 (mc, 10
(m, CHPh-meta), 129.6-131.3 (m, CPh-ipso), 131.7-132.4 (m, CHPh
and
-ortho
para), 171.5 (CO). 31P{1H} NMR (202.5 MHz, CDCl3, 295 K): δ
50.8 (d, J ) 41 Hz), 51.0 (d, J ) 41 Hz). IR (KBr): ν (cm-1) 2924s,
2851m, 1639s, 1436s, 1100s, 750m, 713s, 692s, 608m, 520m, 489m.
MS (FAB): m/z (rel int %) 704 ([M + H]+, 9), 268 (8), 217 (16), 136
(9), 68 (100), 57 (13), 41 (10). Anal. Calcd for C39H47NOP2S3: C,
66.54; H, 6.73; N, 1.99; O, 2.27. Found: C, 66.45; H, 6.62; N, 1.92;
O, 2.35.
3
H, CH2), 1.33 (quin, JH,H ) 7.3 Hz, 2 H, CH2CH2CH2SH), 1.36 (t,
3JH,H ) 7.3 Hz, 1 H, SH), 1.40 (quin, 3JH,H ) 7.3 Hz, 2 H, COCH2CH2),
1.63 (quin, 3JH,H ) 7.3 Hz, 2 H, CH2CH2SH), 1.94 (mc, 2 H, COCH2),
2.13 (mc, 4 H, CH2-COD), 2.43 (mc, 2 H, CH2-COD), 2.54 (mc, 2 H,
CH2-COD), 2.65 (q, 3JH,H ) 7.3 Hz, 2 H, CH2SH), 2.81 (mc, 1 H, NCH2),
2.94 (mc, 1 H, NCH2), 3.02 (mc, 1 H, PCH), 3.12 (mc, 1 H, PCH), 3.59
(mc, 1 H, NCH2), 3.83 (mc, 1 H, NCH2), 4.52 (mc, 1 H, CHCOD), 4.56
(mc, 1 H, CHCOD), 5.20 (mc, 1 H, CHCOD), 5.23 (mc, 1 H, CHCOD), 7.42
(mc, 4 H, CHPh-ortho), 7.55 (mc, 4 H, CHPh-meta), 7.56 (sbr, 4 H,
CHPh-para-BArF), 7.58 (mc, 2 H, CHPh-para), 7.64 (mc, 4 H, CHPh-meta),
7.70 (mc, 2 H, CHPh-para), 7.75 (sb, 8 H, CHPh-ortho-BArF), 7.92 (mc, 4
H, CHPh-ortho). 13C{1H} NMR (125.8 MHz, CD2Cl2, 295 K): δ 24.7
(COCH2CH2), 28.6 (CH2-COD), 28.8 (CH2CH2CH2SH), 29.4 (CH2CH2-
SH), 29.5 (CH2), 29.6 (CH2), 29.7 (CH2), 29.7 (CH2), 29.8 (CH2), 32.2
(CH2-COD), 34.3 (COCH2), 39.3 (CH2SH), 41.7 (ddd, J ) 2 Hz, 18
Hz, 32 Hz, PCH), 43.2 (ddd, J ) 2 Hz, 19 Hz, 32 Hz, PCH), 43.4 (mc,
JP,C ) 4 Hz, 17 Hz, NCH2), 44.4 (dd, JP,C ) 4 Hz, 16 Hz, NCH2), 98.6
(dd, JP,C ) 7 Hz, 8 Hz, CHCOD), 98.7 (dd, JP,C ) 7 Hz, 8 Hz, CHCOD),
104.8 (dd, JP,C ) 7 Hz, 9 Hz, CHCOD), 104.9 (dd, JP,C ) 7 Hz, 9 Hz,
General Procedure for the Synthesis of Functionalized Gold
Particles. Gold particles and all glassware used for the preparation
and storage of gold particles was treated with aqua regia, rinsed with
deionized water, cleaned in a bath consisting of seven parts of
concentrated sulfuric acid and three parts of 30% hydrogen peroxide
(piranha solution), rinsed again with deionized water, and dried for 12
h at 120 °C. All reactions were carried out under argon.
Freshly cleaned gold particles (0.50 g) were transferred into a 10
mL gastight SGE syringe (fitted with a push button luer lock valve
and an integrated filter), containing a solution of the desired disulfide
(0.05 mmol) in freshly distilled CH2Cl2 (4 mL). The syringe was shaken
(80 rpm) under argon for 24 h at 23 °C. The functionalized gold
particles were filtered in the syringe under argon, washed with freshly
distilled CH2Cl2 (8 × 5 mL), and dried in vacuo for 1 h to give the
functionalized gold particles.
[Rh(COD)Cl]2 (0.10 g, 0.20 mmol) and TlBArF
11,12
3
1
(0.43 g, 0.40
CHCOD), 117.9 (sept, JF,C ) 4 Hz, CHPh-para-BArF), 124.9 (q, JF,C
)
)
272 Hz, CF3-BArF), 126.2 (d, 1JP,C ) 42 Hz, CPh-ipso), 126.3 (d, 1JP,C
mmol) were dissolved in freshly distilled CH2Cl2 (10 mL) and stirred
for 1 h at 23 °C. The precipitated TlCl was filtered off and washed
with freshly distilled CH2Cl2 (2 mL). The resulting orange solution
was transferred under argon into a 10 mL gastight SGE syringe (fitted
with a push button luer lock valve and an integrated filter), containing
the functionalized gold particles 2. The syringe was shaken (80 rpm)
under argon for 12 h at 23 °C. The functionalized gold particles were
filtered in the syringe under argon, washed with freshly distilled CH2Cl2
(8 × 5 mL), and dried in vacuo for 1 h to give the functionalized gold
particles 3, which were immediately used for the asymmetric hydro-
genation of methyl R-acetamidocinnamate.
43 Hz, CPh-ipso), 127.7 (d, 1JP,C ) 44 Hz, CPh-ipso), 127.8 (d, 1JP,C ) 44
2
3
Hz, CPh-ipso), 129.2 (q, JF,C ) 31 Hz, JB,C ) 3 Hz, CCF3), 130.4 (d,
3JP,C ) 12 Hz, CHPh-meta), 130.5 (d, JP,C ) 12 Hz, CHPh-meta), 130.6
3
(d, 3JP,C ) 16 Hz, CHPh-meta), 130.7 (d, 3JP,C ) 16 Hz, CHPh-meta), 132.2
4
4
(d, JP,C ) 2.4 Hz, CHPh-para), 133.8 (d, JP,C ) 2.4 Hz, CHPh-para),
135.2 (mb, CHPh-ortho-BArF), 136.9 (d, 2JP,C ) 21 Hz, CHPh-ortho), 137.0
2
1
(d, JP,C ) 21 Hz, CHPh-ortho), 162.1 (q, JB,C ) 50 Hz, CPh-ipso-BArF),
172.1 (CO). 31P{1H} NMR (202.5 MHz, CD2Cl2, 295 K): δ 30.1 (dd,
1JP,Rh ) 149 Hz, 2JP,P′ ) 28 Hz, P), 31.1 (dd, 1JP,Rh ) 149 Hz, 2JP,P′
)
28 Hz, P′). 19F{1H} NMR (470.6 MHz, CD2Cl2, 295 K): δ -63.9 (s).
IR (KBr): ν (cm-1) 2929m, 1653s, 1430mb, 1356s, 1278s, 1127sb,
889m, 839w, 745m, 694mb, 522m. MS (FAB): m/z (rel int %) 850
General Procedure for the Synthesis of n-Alkanethiolate-
Protected Gold Colloids. All glassware used for the preparation and
9
8730 J. AM. CHEM. SOC. VOL. 127, NO. 24, 2005