3534
S.-I. Murahashi et al. / Tetrahedron: Asymmetry 16 (2005) 3527–3535
hexane/2-propanol = 10:1, 0.5 mL/min, retention time:
6.6 Hz, 1H, CH2), 4.92(dd J = 6.6 and 3.3 Hz, 1H,
CH), 7.44–7.74 (m, 4H, ArH); 13C NMR (CDCl3,
125 MHz): d 203.1 (C@O), 155.6, 136.3, 135.1, 129.1,
125.9, 123.0, 68.4, 47.6, 0.1. HRMS (EI) Calcd for
C12H16O2Si m/z 220.0920, found m/z 220.0949. The
enantiomeric excess was determined by HPLC analysis
using a chiral column (CHIRALPAK AS, hexane/
2-propanol = 20:1, 0.5 mL/min).
21
33 min, ½a ¼ þ10:0 (c 1.1, CHCl3) (99% ee)).
D
4.7. General procedure for the Mn(salen) (1)-catalyzed
oxidation of silyl ethers with iodosylbenzene
To a mixture of silyl ether (0.10 mmol), 1 (1.8 mg,
0.0050 mmol), and CH3CN (1.0 mL) was added iodosyl-
benzene (44 mg, 0.20 mmol) at room temperature. The
mixture was stirred under an argon atmosphere for
6 h. The conversion of the starting substrate and the
yield of product were determined by GLC analysis using
an internal standard. The product ketone was isolated
by column chromatography (SiO2, hexane/ethyl ace-
tate). The results are shown in Table 4.
4.8.3. (R)-3-Triisopropylsiloxy-1-indanone 13c. Color-
less solid; mp = 41.4–42.8 ꢁC; IR (KBr): 2944, 1715
(C@O), 1603, 1462, 1281, 1237, 1215, 1105, 1084,
1
1047, 932, 882, 837, 799, 762 cmÀ1; H NMR (CDCl3,
500 MHz): d 1.14–1.22 (m, 21H, Si(iPr)3), 2.67 (dd,
J = 18.1 and 3.7 Hz, 1H, CH2), 3.11 (dd, J = 18.1 and
6.4 Hz, 1H, CH2), 5.52(dd, J = 6.6 and 3.7 Hz, 1H,
CH), 7.45–7.48 (m, 1H, ArH), 7.66–7.75 (m, 3H,
ArH); 13C NMR (CDCl3, 125 MHz): d 203.3 (C@O),
156.5, 136.4, 135.3, 129.2, 126.0, 123.2, 69.3, 48.7,
18.3, 18.2, 12.5. The enantiomeric excess was determined
by HPLC analysis using a chiral column (CHIRALPAK
AD, hexane/2-propanol = 500:1, 0.5 mL/min).
4.8. General procedure for the Mn(salen) 3-catalyzed
enantioselective oxidation of 1,3- and 1,4-disilyl ethers
to optically active b- and c-siloxyketones with
iodosylbenzene
A 25 mL Schlenk flask equipped with a magnetic stirring
bar was charged with a substrate (0.050 mmol), Mn(sa-
len) 3 (0.0025 mmol), 4-phenylpyridine N-oxide (4.3 mg,
0.025 mmol), and CH2Cl2 (1.0 mL). To the mixture was
added iodosylbenzene (22.0 mg, 0.10 mmol) at the
appropriate temperature. The mixture was stirred for
17 h. After the mixture was poured into a 0.2M solution
of triphenylphosphine in CH2Cl2 (0.2mL), the mixture
was analyzed by GLC to determine the conversion of
starting materials and the yield of products using an
internal standard (n-pentadecane). The product siloxy-
ketone was isolated by column chromatography (SiO2,
hexane/ethyl acetate = 5:1). The results are shown in
Table 5 and Eqs. 7 and 8. The spectral data of the prod-
ucts and the conditions for the determination of enan-
tiomeric excess are shown below.
4.8.4. (R)-3-tert-Butyldiphenylsiloxy-1-indanone 13d. Col-
orless oil; IR (neat): 2959, 2859, 1721 (C@O), 1605,
1427, 1362, 1281, 1242, 1215, 1159, 1113, 1078, 1047,
943, 822, 762, 741, 702 cmÀ1
;
1H NMR (CDCl3,
500 MHz): d 1.12(s, 9H, tBu), 2.63 (dd, J = 18.5 and
3.4 Hz, 1H, CH2), 2.75 (dd, J = 18.5 and 6.4 Hz, 1H,
CH2), 5.40 (dd, J = 6.4 and 3.4 Hz, 1H, CH), 7.38–
7.49 (m, 8H, ArH), 7.58–7.61 (m, 1H, ArH), 7.69–7.71
(m, 3H, ArH), 7.75–7.76 (m, 2H, ArH); 13C NMR
(CDCl3, 125 MHz): d 203.0 (C@O), 157.7, 135.9,
135.8, 134.9, 133.5, 133.4, 130.1, 130.0, 128.9, 127.9,
126.0, 122.9, 69.7, 47.7, 27.0, 19.2. The enantiomeric
excess was determined by HPLC analysis using a chiral
column (CHIRALPAK As, hexane/2-propanol = 20:1,
0.5 mL/min).
4.8.1. (R)-3-tert-Butyldimethylsilyloxy-1-indanone 13a.
Colorless solid; mp 51.2–52.0 ꢁC; IR (neat): 3072,
3036, 2955, 2930, 1722 (C@O), 1604, 1471, 1464, 1361,
1278, 1217, 1161, 1107, 1080, 1047, 1006, 933,
4.8.5. (R)-3-Hydroxy-1-indanone 13e. Colorless oil;
23
½a ¼ À87:5 (c 2.0, CHCl3) for 13e with 62% ee (R);
IRD(neat): 3416 (OH), 1712(C @O), 1606, 1466, 1397,
777 cmÀ1; H NMR (CDCl3, 500 MHz): d 0.19 (s, 3H,
1333, 1283, 1244, 1213, 1099, 1049, 765 cmÀ1 1H
;
1
t
CH3), 0.23 (s, 3H, CH3), 0.96 (s, 9H, Bu), 2.60 (dd,
NMR (CDCl3, 500 MHz): d 2.61 (ddd, J = 18.8, 2.1,
and 0.9 Hz, 1H, CH2), 2.87 (s, 1H, OH), 3.11 (ddd,
J = 18.9, 6.8, and 0.9 Hz, 1H, CH2, 5.43 (dd, J = 6.6
and 2.5 Hz, 1H, CH), 7.47–7.34 (m, 4H, ArH); 13C
NMR (CDCl3, 125 MHz): d 203.5 (C@O), 155.1,
136.3, 135.3, 129.5, 125.9, 123.2, 68.4, 47.1; HRMS
(EI) calcd for C9H8O2 m/z 148.0524, found m/z
148.0508; HPLC data as follows, (R)-13e isomer: CHI-
RALCEL OB-H, hexane/2-propanol = 10:1, 0.5 mL/
min, retention time: 24 min. (S)-13e isomer: CHIRAL-
CEL OB-H, hexane/2-propanol = 10:1, 0.5 mL/min,
retention time: 28 min.
J = 18.5 and 3.4 Hz, 1H, CH2), 3.07 (dd, J = 18.3 and
6.6 Hz, 1H, CH2), 5.39 (dd J = 6.8 and 3.5 Hz, 1H,
CH), 7.74 (d, J = 7.6 Hz, 1H, ArH), 7.26–7.75 (m, 3H,
ArH); 13C NMR (CDCl3, 125 MHz): d 203.1 (C@O),
156.0, 136.2, 135.0, 129.0, 125.8, 123.0, 68.9, 47.9,
25.8, 18.2, À4.4, À4.7. Anal. Calcd for C15H22O2Si:
C, 68.65; H, 8.45. Found; C, 68.50; H, 8.54. MS (EI):
t
m/z 205 (M+À Bu), 163, 147, 131, 103, 75, 59, 45;
HPLC data as follows, (R)-13a isomer: CHIRALPAK
AD, hexane/2-propanol = 500:1, 0.5 mL/min, reten-
tion time: 22 min. (S)-13a isomer: CHIRALPAK AD,
hexane/2-propanol = 500:1, 0.5 mL/min, retention time:
27 min.
4.8.6. (S)-3-tert-Butyldimethylsiloxy-2,2-dimethyl-1-inda-
¼
23
none (15). Colorless solid; mp 42.2–43.3 ꢁC; ½a
4.8.2. (R)-3-Trimethylsilyloxy-1-indanone 13b. Color-
À9:2 (c 0.07, CHCl3) for 15 with 80% ee (S);DIR
less oil; IR (neat): 2959, 1721, 1604, 1464, 1350, 1261,
(KBr): 2959, 2859, 1712 (C@O), 1607, 1468, 1379,
1
1
1252, 1105, 1073, 934, 874, 845, 760 cmÀ1; H NMR
1217, 1111, 1082, 1007, 876, 775, 754 cmÀ1; H NMR
(CDCl3, 500 MHz): d 0.25 (s, 9H, Si(CH3)3), 2.60 (dd,
J = 18.4 and 3.3 Hz, 1H, CH2), 3.06 (dd, J = 18.5 and
(CDCl3, 500 MHz): d 0.21 (s, 3H, CH3), 0.28 (s, 3H,
CH3), 0.98 (s, 9H, Bu), 1.07 (s, 3H, CH3), 1.28 (s, 3H,
t