Pyridyl group assisted deprotonation of a methyl group on silicon: Complex induced proximity effect and novel hydroxymethylation

Article abstract of DOI:10.1021/jo015528g

A novel methodology for the deprotonation of a methyl group on silicon has been developed. This newly developed α-lithiation protocol is based on the intramolecular pyridyl group coordination to stabilize the α-silyl carbanion together with the inherent silicon α effect. It was found that the deprotonation (t-BuLi/Et₂O/-78 °C) occurs with 2-pyridyltrimethylsilane but not with other related silanes such as phenyltrimethylsilane, 3-pyridyltrimethylsilane, and 4-pyridyltrimethylsilane. It seems that this deprotonation proceeded through the agency of the complex-induced proximity effect (CIPE) of a 2-pyridyl group on silicon. ¹H NMR analysis of (2-pyridyldimethylsilyl)methyllithium revealed the intramolecular coordination of a pyridyl group to lithium. (2-Pyridyldimethylsilyl)-methyllithium was found to react with chlorosilanes, hydrosilanes, chlorostannanes, bromine, iodine, organic bromides, aldehydes, and ketones in good to excellent yields. The resultant adducts were further oxidized with H₂O₂/KF to give the corresponding alcohols in excellent yields. Thus, this two-step transformation provides an efficient method for the nucleophilic hydroxymethylation.

Full text of DOI:10.1021/jo015528g

3970
J . Org. Chem. 2001, 66, 3970-3976
P yr id yl Gr ou p Assisted Dep r oton a tion of a Meth yl Gr ou p on
Silicon : Com p lex In d u ced P r oxim ity Effect a n d Novel
Hyd r oxym eth yla tion
Kenichiro Itami, Toshiyuki Kamei, Koichi Mitsudo, Toshiki Nokami, and J un-ichi Yoshida*
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering,
Kyoto University, Yoshida, Kyoto 606-8501, J apan
yoshida@sbchem.kyoto-u.ac.jp
Received J anuary 17, 2001
A novel methodology for the deprotonation of a methyl group on silicon has been developed. This
newly developed R-lithiation protocol is based on the intramolecular pyridyl group coordination to
stabilize the R-silyl carbanion together with the inherent silicon R effect. It was found that the
deprotonation (t-BuLi/Et2O/-78 °C) occurs with 2-pyridyltrimethylsilane but not with other related
silanes such as phenyltrimethylsilane, 3-pyridyltrimethylsilane, and 4-pyridyltrimethylsilane. It
seems that this deprotonation proceeded through the agency of the complex-induced proximity effect
1
(CIPE) of a 2-pyridyl group on silicon. H NMR analysis of (2-pyridyldimethylsilyl)methyllithium
revealed the intramolecular coordination of a pyridyl group to lithium. (2-Pyridyldimethylsilyl)-
methyllithium was found to react with chlorosilanes, hydrosilanes, chlorostannanes, bromine, iodine,
organic bromides, aldehydes, and ketones in good to excellent yields. The resultant adducts were
further oxidized with H2O2/KF to give the corresponding alcohols in excellent yields. Thus, this
two-step transformation provides an efficient method for the nucleophilic hydroxymethylation.
In tr od u ction
Since their introduction by Peterson in 1968,1 the
generation and the reactions of R-silyl carbanions is a
subject of great interest in organic synthesis.2 They have
been widely used in Peterson-type olefination,3 nucleo-
philic hydroxymethylation,4 and their variants. R-Silyl
carbanions are usually generated in four different ways:
(1) Grignard reagent formation from the corresponding
R-halosilane; (2) deprotonation by lithiating reagent such
as butyllithium; (3) metal-heteroatom (S, Sn, Si, Se)
exchange reaction; (4) addition of alkyllithium to vinyl-
silane. Among these R-silyl carbanion-generating meth-
ods, deprotonation by butyllithium is by far the most
convenient way, since R-halosilanes, R-heteroatom sub-
stituted silanes, and vinylsilanes are not always readily
available. In most cases, together with the stabilization
of the carbanion by the R silyl group, additional stabiliza-
tion effects by neighboring heteroatoms or electron-
withdrawing groups have been exploited for their gen-
eration (eq 1).5
ably, this sluggish deprotonation stems from the lack of
additional stabilization effects.7
Thus, in silane deprotonation chemistry, a methyl
group on silicon has been recognized as the most difficult
group to deprotonate.8 Nevertheless, there are several
successes in the methyl group deprotonation including
our recent work (Scheme 1).9,10 Hosomi has reported that
alkoxytrimethylsilane bearing a dimethylamino group
can be easily deprotonated by t-BuLi to give the corre-
sponding R-silyl carbanion.9a It has been mentioned that
(5) (a) Chan, T. H.; Chang, E.; Vinokur, E. Tetrahedron Lett. 1970,
1137. (b) Carey, F. A.; Court, A. S. J . Org. Chem. 1972, 37, 939. (c)
Carey, F. A.; Hernandez, O. J . Org. Chem. 1973, 38, 2670. (d) Colvin,
E. W.; Hamill, B. J . Chem. Commun. 1973, 151. (e) Grobel, B.-T.;
Seebach, D. Angew. Chem., Int. Ed. Engl. 1974, 13, 83. (f) Ojima, I.;
Kumagai, M.; Nagai, Y. Tetrahedron Lett. 1974, 4005. (g) Hartzell, S.
L.; Rathke, M. W. Tetrahedron Lett. 1976, 2737. (h) Sachdev, K.;
Sachdev, H. S. Tetrahedron Lett. 1976, 4223. (i) Burford, C.; Cooke,
F.; Ehlinger, E.; Magnus, P. J . Am. Chem. Soc. 1977, 99, 4536. (j)
Ayalon-Chass, D.; Ehlinger, E.; Magnus, P. Chem. Commun. 1977, 772.
(k) Magnus, P.; Roy, G. Chem. Commun. 1979, 822.
However, without such additional effects, the genera-
tion of R-silyl carbanion is known as a formidable task
by means of hydrogen-metal exchange. For example, in
the case of Me4Si, the deprotonation (n-BuLi in TMEDA)
is extremely slow and inefficient, giving the correspond-
ing R-silyl carbanion in 36% yield after 4 days.6 Presum-
(6) Peterson, D. J . J . Organomet. Chem. 1967, 9, 373.
(7) For quantitative studies of R-silyl carbanion stabilization, see:
(a) Wetzel, D.; Brauman, J . I. J . Am. Chem. Soc. 1988, 110, 8333. (b)
Brinkman, E. A.; Berger, S.; Brauman, J . I. J . Am. Chem. Soc. 1994,
116, 8304 and references therein. See also, (c) Damrauer, R.; Kass, S.
R.; DePuy, C. H. Organometallics 1988, 7, 637. (d) Zhang, S.; Zhang,
X. M.; Bordwell, F. G. J . Am. Chem. Soc. 1995, 117, 602.
(8) (a) Gornowicz, G. A.; West, R. J . Am. Chem. Soc. 1968, 90, 4478.
(b) Frye, C. L.; Salinger, R. M.; Fearon, F. W. G.; Klosowski, J . M.;
DeYoung, T. J . Org. Chem. 1970, 35, 1308. (c) Pinkerton, F. H.;
Thames, S. F. J . Organomet. Chem. 1971, 29, C4. (d) Bates, T. F.;
Dandekar, S. A.; Longlet, J . J .; Wood, K. A.; Thomas, R. D. J .
Organomet. Chem. 2000, 595, 87.
(1) Peterson, D. J . J . Org. Chem. 1968, 33, 780.
(2) For reviews, see: (a) Brook, M. A. Silicon in Organic, Organo-
metallic, and Polymer Chemistry; J ohn Wiley & Sons: New York, 2000.
(b) Colvin, E. W. Silicon Reagents in Organic Synthesis; Academic
Press: London, 1988. (c) Weber, W. P. Silicon Reagents for Organic
Synthesis; Springer-Verlag: Berlin, 1983. (d) Magnus, P. Aldrichim.
Acta 1980, 13, 238.
(3) For a review, see: Ager, D. J . Org. React. 1990, 38, 1.
(4) Tamao, K.; Ishida, N.; Ito, Y.; Kumada, M. Org. Synth. 1990,
69, 96.
10.1021/jo015528g CCC: $20.00 © 2001 American Chemical Society
Published on Web 05/09/2001

Deprotonation of a Methyl Group on Silicon
J . Org. Chem., Vol. 66, No. 11, 2001 3971
Sch em e 1. Coor d in a tion -Assisted Dep r oton a tion of Meth yl Gr ou p on Silicon
Ta ble 1. Con d ition s for th e Dep r oton a tion of 1
both oxygen and nitrogen atoms are necessary for the
deprotonation, indicating the importance of both the
inductive effect of oxygen and the coordination effect of
nitrogen. Friesen9b and Quayle9c also observed similar
effects in the deprotonation of a tert-butyldimethylsilyl
group. Snieckus has reported that an aryltrimethylsilane-
bearing amido group undergoes facile deprotonation by
lithium diisopropylamide (LDA).9d Klumpp9e and Stroh-
mann9f have also reported the methyl group deprotona-
tion by taking advantage of the intramolecular amino
group coordination. We have recently developed the
extremely facile deprotonation of methyl group on silicon
by virtue of intramolecular assistance of 2-pyridyl
group.10,11 Herein, we describe the full details of our
studies for the efficient deprotonation of methyl group
on silicon based on the intramolecular pyridyl group
coordination. Related deprotonation of 2-pyridylsilanes
and novel nucleophilic hydroxymethylation are also
described.
lithiating
reagent
(equiv)
result
(yield, %)
entry
solvent
conditions
1
2
3
4
5
n-BuLi (1.1) Et2O -78 °C, 30 min no reaction
n-BuLi (1.1) Et2O 0 °C, 30 min complex mixture
Et2O -78 °C, 30 min 3a (60)
Et2O -78 °C, 30 min 3a (93)
Et2O 0 °C, 2 h 3a (69)
s-BuLi (1.1)
t-BuLi (1.1)
LDA (1.1)
anionic species but gave a complex mixture of unidenti-
fied products after the treatment with Me3SiCl (Table 1,
entry 2). Presumably, n-BuLi attacked the pyridine ring
as a nucleophile. On the other hand, the deprotonation
proceeded with s-BuLi at -78 °C and 3a was isolated in
60% yield together with some unidentified products
(Table 1, entry 3). The use of t-BuLi gave rise to the
quantitative deprotonation of 1, and 3a was isolated in
93% yield (Table 1, entry 4). Lithium diisopropylamide
(LDA) was also found to be effective for the deprotonation
at 0 °C (Table 1, entry 5). When we added more LDA
and Me3SiCl in the reaction mixture, the doubly silylated
product became the major product because 3a is more
acidic than starting material 1. Premixing of LDA and
Me3SiCl prior to the addition of 1 also resulted in the
production of considerable doubly silylated product.
Com p lex In d u ced P r oxim ity Effect. We assume
that the deprotonation of 1 proceeded through the agency
of what Beak and Meyers have termed “complex induced
proximity effect (CIPE)”.13 In the reaction, there must
be a preequilibrium complex (A) of 1 and t-BuLi prior to
the subsequent deprotonation (Scheme 2).14 As a result,
the formation of A renders the deprotonation event
Resu lts a n d Discu ssion
Dep r oton a tion of 2-P yr id yltr im eth ylsila n e. We
envisioned that the methyl group of 2-pyridyltrimethyl-
silane (1)12 should be easily deprotonated based on the
efficient coordination of the intramolecular pyridyl group.
Thus, we examined the reagent for the deprotonation,
and its efficiency was evaluated by the reaction of thus-
generated (2-pyridyldimethylsilyl)methyllithium (2) and
trimethylsilyl chloride (Table 1). The deprotonation of 1
did not occur with n-BuLi at -78 °C (Table 1, entry 1).
Raising the temperature to 0 °C seemed to generate some
(9) (a) Hosomi, A.; Kohra, S.; Tominaga, Y.; Shoji, M.; Sakurai, H.
Chem. Pharm. Bull. 1987, 35, 1663. (b) Friesen, R. W.; Sturino, C. F.;
Daljeet, A. K.; Kolaczewska, A. J . Org. Chem. 1991, 56, 1944. (c)
Imanieh, H.; Quayle, P.; Voaden, M.; Conway, J .; Street, S. D. A.
Tetrahedron Lett. 1992, 33, 543. (d) Brough, P. A.; Fisher, S.; Zhao,
B.; Thomas, R. C.; Snieckus, V. Tetrahedron Lett. 1996, 37, 2915. (e)
Luitjes, H.; de Kanter, F. J . J .; Schakel, M.; Schmitz, R. F.; Klumpp,
G. W. J . Am. Chem. Soc. 1995, 117, 4179. (f) Abele, B. C.; Strohmann,
C. In Organosilicon Chemistry III; Auner, N., Weis, J ., Eds.; Wiley-
VCH: Weinheim, 1998; p 206.
(10) (a) Itami, K.; Mitsudo, K.; Yoshida, J . Tetrahedron Lett. 1999,
40, 5533. (b) Itami, K.; Mitsudo, K.; Yoshida, J . Tetrahedron Lett. 1999,
40, 5537.
(11) For other related chemistry of 2-pyridylsilanes, see: (a) Yoshida,
J .; Itami, K.; Mitsudo, K.; Suga, S. Tetrahedron Lett. 1999, 40, 3403.
(b) Itami, K.; Mitsudo, K.; Yoshida, J . J . Org. Chem. 1999, 64, 8709.
(c) Itami, K.; Nokami, T.; Yoshida, J . Org. Lett. 2000, 2, 1299. (d) Itami,
K.; Mitsudo, K.; Kamei, T.; Koike, T.; Nokami, T.; Yoshida, J . J . Am.
Chem. Soc. 2000, 122, 12013. (e) Itami, K.; Nokami, T.; Yoshida, J .
Angew. Chem., Int. Ed. 2001, 40, 1074.
(13) For reviews on CIPE, see: (a) Beak, P.; Meyers, A. I. Acc. Chem.
Res. 1986, 19, 356. (b) Snieckus, V. Chem. Rev. 1990, 90, 879. (c) Beak,
P.; Basu, A.; Gallagher, D. J .; Park, Y. S.; Thayumanavan, S. Acc.
Chem. Res. 1996, 29, 552.
(14) Trost has reported a similar coordination effect in the depro-
tonation of imino thioethers. Trost, B. M.; Vaultier, M.; Santiago, M.
L. J . Am. Chem. Soc. 1980, 102, 7929.
(12) Anderson, D. G.; Bradney, M. A. M.; Webster, D. E. J . Chem.
Soc. B 1968, 450.

3972 J . Org. Chem., Vol. 66, No. 11, 2001
Itami et al.
Sch em e 2. Com p lex In d u ced P r oxim ity Effect in
th e Dep r oton a tion of 1
intramolecular in nature. The importance of this pre-
equilibrium complex formation was further supported by
the observation of dramatic solvent and additive effects
in this deprotonation. When the reaction of 1 and t-BuLi
was performed in THF instead of Et2O or in the presence
of an equimolar amount of TMEDA in Et2O, the desired
deprotonation did not occur at all, giving a complex
mixture after the treatment with Me3SiCl. These results
may be attributed to the inhibition of preequilibrium
complex formation by the external coordinating solvent
(THF) or additive (TMEDA).15
To substantiate that the facile deprotonation of 1 is
attributed to the CIPE together with an inherent silicon
R effect, we next examined the deprotonation of phenyl-
trimethylsilane (4), 3-pyridyltrimethylsilane (5),12 and
4-pyridyltrimethylsilane (7),12 where the CIPE cannot be
expected as in the case of 1. In the case of 4, no reaction
occurred with the addition of t-BuLi. Upon treatment
with t-BuLi, neither 5 nor 7 generated the desired R-silyl
carbanion, and in both cases, nucleophilic attack of t-BuLi
to the pyridine ring occurred (eqs 3 and 4). This pro-
nounced difference between 1 and 4, 5, or 7 implies the
governance of CIPE in the deprotonation of 1.
1
F igu r e 1. Comparison of H NMR of 1 and 2 in Et2O-d10 at
-78 °C.
Although the structure of 2 has not been determined by
X-ray crystallography,16 we examined the structure of 2
in solution using 1H NMR spectroscopy in Et2O-d10 at
1
-78 °C. For comparison, H NMR spectroscopy was also
taken for the parent 1 under identical conditions (Figure
1). When compared to 1, noticeable changes in the
pyridine ring chemical shift were observed for 2. Down-
field shifts were observed for H1, H2, and H3, which
indicate the intramolecular pyridyl group coordination
to lithium. In addition,1H NMR spectrum of 2 showed
two singlets due to the two methyl groups on silicon and
two sets of doublet (J ) 11.0 Hz) due to the two protons
on R-carbon, which coalesced at 0 °C. The observed
nonequivalence of these protons is most likely attributed
to the coordination induced rigid five-membered cyclic
structure of 2.
Rela ted P yr id yl Gr ou p Assisted Dep r oton a tion .
Next, we investigated the deprotonation of other related
2-pyridylsilanes. As in the case of 1, 2-pyridyl(phenyl)-
dimethylsilane (10) and 2-pyridyldiphenylmethylsilane
(12) were easily deprotonated by t-BuLi in Et2O. After
treatment with Me3SiCl, 11 and 13 were isolated in 90%
and 72% yields, respectively (eqs 5 and 6). When 2-pyr-
idyl(benzyl)dimethylsilane (14) was subjected to the
standard conditions, deprotonation occurred at two dif-
ferent positions. The deprotonation at the benzylic proton
led to 15 and the deprotonation at the methyl proton led
to 16 after quenching with Me3SiCl (eq 7). It may be
reasonable to assume that the mainly generated (silyl)-
benzyllithium is thermodynamically more stable than the
(silyl)methyllithium.
Rea ction s of 2 w ith Va r iou s Electr op h iles. Having
established the facile deprotonation of 1, we subsequently
embarked on the reaction of thus-generated 2 with
various electrophiles, and the results are listed in Table
2. Not only chlorosilanes (Table 2, entries 1 and 2) but
also hydrosilane were effective in this reaction (Table 2,
entry 3). Chlorostannanes also work as excellent elec-
trophiles (Table 2, entries 4 and 5). The reaction with
bromine and iodine gave the synthetically useful silyl-
methyl halides (Table 2, entries 6 and 7). Allyl, benzyl,
Coor d in a tion of th e P yr id yl Gr ou p in 2-P yMe2-
SiCH 2Li. In addition to the kinetic preference for the
deprotonation of 1 by CIPE, we presume that the
stabilization of generated organolithium 2 by the in-
tramolecular pyridyl group coordination is also respon-
sible for the efficiency of this deprotonation process.
(16) Very recently, Eaborn and Smith have established the pyridyl
group coordination to lithium in the very similar 2-PyMe2SiC(SiMe3)2-
Li‚THF complex by X-ray crystal structure analysis. Al-J uaid, S. S.;
Eaborn, C.; Hitchcock, P. B.; Hill, M. S.; Smith, J . D. Organometallics
2000, 19, 3224.
(15) For the BuLi/TMEDA complex, see: Chadwick, S. T.; Rennels,
R. A.; Rutherford, J . L.; Collum, D. B. J . Am. Chem. Soc. 2000, 122,
8640 and references therein.

Deprotonation of a Methyl Group on Silicon
J . Org. Chem., Vol. 66, No. 11, 2001 3973
Ta ble 2. Rea ction s of 2 w ith Va r iou s Electr op h iles
and alkyl bromides were also found to be excellent
electrophiles (Table 2, entries 8-10). Unfortunately,
secondary and tertiary alkyl halides were not applicable
in this reaction, partially due to the high basicity of 2.
Aromatic and aliphatic aldehydes were also found to be
applicable (Table 2, entries 11-13). Ketones also gave
their adducts, albeit with lower yields (Table 2, entries
14 and 15).
Nu cleop h ilic Hyd r oxym eth yla tion . Recently,10,11
we have found that the 2-pyridyldimethylsilyl (2-PyMe2-
Si) group is a versatile silyl group that is convertible to
the hydroxyl group with much milder conditions com-
pared to the well-known PhMe2Si group.17,18 We envi-
sioned that, when connected with our previous findings
of the oxidative cleavage of 2-PyMe2Si group, 2 can be
regarded as a novel nucleophilic hydroxymethylating
agent (Scheme 3).4,19 This procedure may be complemen-
tary to the conventional electrophilic hydroxymethylation
using formaldehyde.
(17) For a review on PhMe2Si group oxidation, see: Fleming, I.;
Henning, R.; Parker, D. C.; Plaut. H. E.; Sanderson, P. E. J . J . Chem.
Soc., Perkin Trans. 1 1995, 317.
(18) For excellent reviews on oxidative cleavage of carbon-silicon
bonds, see: (a) Tamao, K. In Advances in Silicon Chemistry, Larson,
G. L., Ed.; J AI Press Inc., 1996; Vol. 3,
p 1. (b) Fleming, I.
ChemTracts: Org. Chem. 1996, 1. (c) J ones, G. R.; Landais, Y.
Tetrahedron 1996, 52, 7599.
(19) (a) Rathke, M. W.; Kow, R. J . Am. Chem. Soc. 1972, 94, 6854.
(b) Beak, P.; McKinnie, B. G. J . Am. Chem. Soc. 1977, 99, 5213. (c)
Stille, W. C.; Mitra, A. J . Am. Chem. Soc. 1978, 100, 1929. (d) Wissner,
A. Tetrahedron Lett. 1978, 2749. (e) Meyer, N.; Seebach, D. Chem. Ber.
1980, 113, 1290. (f) Pelter, A. Chem. Soc. Rev. 1982, 11, 191. (g) Kosugi,
M.; Sumiya, T.; Ohhashi, K.; Sano, H.; Migita, T. Chem. Lett. 1985,
997.
Thus, we examined the oxidative cleavage of carbon-
silicon bonds of (2-pyridyldimethylsilyl)methylated prod-
ucts in Table 2. Listed in Table 3 are the representative
results for the H2O2 oxidation. The oxidations were
performed by modified Tamao procedure11b using 30%

3974 J . Org. Chem., Vol. 66, No. 11, 2001
Itami et al.
sodium benzophenone ketyl prior to use. 2-Pyridyltrimethyl-
silane (1),12 3-pyridyltrimethylsilane (5),12 and 4-pyridyltri-
methylsilane (7)12 were prepared according to the literature
procedures. NMR spectra were recorded on a Varian GEMINI-
2000 (1H 300 MHz, 13C 75 MHz) spectrometer in CDCl3 with
internal standards (7.26 ppm 1H, 77.0 ppm 13C). EI mass
spectra were recorded on a J MS-SX102A spectrometer. FAB
mass spectra were recorded on a J MS-HX110A spectrometer.
Infrared spectra were recorded on a Shimadzu FTIR-8100
spectrophotometer.
Sch em e 3. (2-P yr id yld im eth ylsilyl)m eth yllith iu m
(2) a s a Novel Hyd r oxym eth yla tin g Rea gen t
(2-P yr id yld im eth ylsilyl)m eth yllith iu m (2). To a solution
of 2-pyridyltrimethylsilane (1) (151 mg, 1.0 mmol) in dry Et2O
(2 mL) was added dropwise a solution of t-BuLi (1.16 mmol,
1.64 M solution in pentane) at -78 °C under argon. The
mixture was stirred for additional 30 min to afford an orange
ether solution of (2-pyridyldimethylsilyl)methyllithium (2).
Ta ble 3. H2O2 Oxid a tion of
(2-P yr id yld im eth ylsilyl)m eth yla ted P r od u cts
[(2-P yr id yld im eth ylsilyl)m eth yl]tr im eth ylsila n e (3a ).
To a solution of 2 (1.0 mmol) in Et2O (2 mL) was added
chlorotrimethylsilane (130 mg, 1.2 mmol) at -78 °C. After the
reaction mixture was stirred at 0 °C for 3 h, 1 N aqueous HCl
(5 mL) was added to the mixture, and the aqueous phase was
separated. The organic phase was extracted with 1 N aqueous
HCl (4 × 5 mL). The combined aqueous phase was neutralized
by the addition of NaHCO3 and was extracted with Et2O (3 ×
10 mL). Drying over MgSO4 and removal of solvent under
reduced pressure afforded 3a (208 mg, 93%, >95% pure as
1
judged by H NMR and capillary GC analysis) as a colorless
oil: 1H NMR δ -0.05 (s, 9 H), 0.07 (s, 2 H), 0.33 (s, 6 H), 7.14
(ddd, J ) 7.5, 5.1, 1.5 Hz, 1 H), 7.48 (ddd, J ) 7.5, 1.5, 1.2 Hz,
1 H), 7.54 (td, J ) 7.5, 1.8 Hz, 1 H), 8.75 (ddd, J ) 5.1, 1.8, 1.2
Hz, 1 H); 13C NMR δ -1.0, 1.0, 2.1, 122.5, 128.6, 133.9, 150.1,
169.2. IR (neat) 1576, 1559, 1451, 1418, 1248, 1138, 1053 cm-1
;
HRMS (EI) m/z calcd for C11H21NSi2 223.1213, found 223.1211.
Anal. Calcd for C11H21NSi2: C, 59.12; H, 9.47; N, 6.27. Found:
C, 59.35; H, 9.53; N, 6.22.
2-ter t-Bu t yl-1,5-b is(t r im et h ylsilyl)-1,2-d ih yd r op yr i-
d in e (6): 1H NMR δ 0.02 (s, 9 H), 0.19 (s, 9 H), 0.79 (s, 9 H),
3.44 (dd, J ) 6.0, 0.9 Hz, 1 H), 5.13 (ddd, J ) 9.0, 6.0, 1.2 Hz,
1 H), 6.05 (dd, J ) 9.0, 0.9 Hz, 1 H), 6.31 (d, J ) 1.2 Hz, 1 H);
13C NMR δ -1.5, -0.1, 25.3, 39.8, 60.1, 109.7, 112.6, 126.2,
141.6; IR (neat) 1619, 1541, 1252 cm-1; HRMS (EI) m/z calcd
for C14H28NSi2 (M - CH3)+ 266.1760, found 266.1755. Anal.
Calcd for C15H31NSi2: C, 63.98; H, 11.10; N, 4.97. Found: C,
63.79; H, 11.32; N, 4.75.
2-ter t-Bu t yl-1,4-b is(t r im et h ylsilyl)-1,2-d ih yd r op yr i-
d in e (8): 1H NMR δ 0.07 (s, 9 H), 0.16 (s, 9 H), 0.81 (s, 9 H),
3.38 (dd, J ) 6.0, 0.9 Hz, 1 H), 5.09 (dd, J ) 6.9, 0.9 Hz, 1 H),
5.28 (dt, J ) 6.0, 0.9 Hz, 1 H), 6.14 (dt, J ) 6.9, 0.9 Hz, 1 H);
13C NMR δ -1.8, -0.2, 25.5, 39.8, 60.1, 106.1, 120.4, 133.6,
134.4.
2-ter t-Bu tyl-4-tr im eth ylsilylp yr id in e (9): 1H NMR δ
0.28 (s, 9 H), 1.38 (s, 9 H), 7.18 (dd, J ) 4.8, 0.9 Hz, 1 H), 7.43
(t, J ) 0.9 Hz, 1 H), 8.52 (dd, J ) 4.8, 0.9 Hz, 1 H); 13C NMR
δ -1.7, 30.3, 37.3, 123.1, 125.0, 147.4, 150.1, 167.8. IR (neat)
1584, 1252, 1156 cm-1; HRMS (EI) m/z calcd for C12H21NSi
207.1443, found 207.1446.
H2O2 (30 equiv), KF (2.0 equiv), and KHCO3 (2.0 equiv)
in MeOH/THF (1/1) at 50 °C. In all cases, the oxidation
proceeded well to give the corresponding alcohols, which
are regarded as overall hydroxymethylated products of
the electrophiles.20 Noteworthy was that these oxidative
conditions were also applicable to â-hydroxysilanes,
which are prone to undergo Peterson-type elimination to
form alkenes.3
Con clu sion
In conclusion, we have developed a novel methodology
for the deprotonation of a methyl group on silicon. This
protocol is based on the intramolecular pyridyl group
coordination to stabilize the R-silyl carbanion together
with the inherent silicon R effect. It is suggested that this
deprotonation proceeded through the agency of complex
induced proximity effect (CIPE) of 2-pyridyl group on
silicon. (2-Pyridyldimethylsilyl)methyllithium (2) was
found to react with various electrophiles, and the result-
ant adducts were further oxidized with H2O2/KF to give
the corresponding alcohols in good to excellent overall
yields. This two-step transformation provides an efficient
method for the nucleophilic hydroxymethylation.
2-P yr id yl(p h en yl)d im eth ylsila n e (10): 1H NMR δ 0.63
(s, 6 H), 7.19 (ddd, J ) 7.5, 4.8, 1.5 Hz, 1 H), 7.35-7.40 (m, 3
H), 7.44 (dm, J ) 7.5 Hz, 1 H), 7.55 (td, J ) 7.5, 1.5 Hz, 1 H),
7.59-7.64 (m, 2 H), 8.81 (dm, J ) 4.8 Hz, 1 H); 13C NMR δ
-3.3, 122.8, 127.9, 129.3, 129.7, 134.0, 134.3, 137.3, 150.3,
166.7. IR (neat) 1574, 1559, 1453, 1428, 1246, 1109 cm-1
;
HRMS (EI) m/z calcd for C13H15NSi 213.0974, found 213.0975.
Anal. Calcd for C13H15NSi: C, 73.18; H, 7.09; N, 6.57. Found:
C, 73.44; H, 7.18; N, 6.63.
Exp er im en ta l Section
[[2-P yr id yl(p h en yl)m et h ylsilyl]m et h yl]t r im et h ylsi-
la n e (11): 1H NMR δ -0.10 (s, 9 H), 0.37 (d, J ) 14.1 Hz, 1
H), 0.48 (d, J ) 14.1 Hz, 1 H), 0.67 (s, 3 H), 7.18 (ddd, J ) 7.5,
4.8, 1.5 Hz, 1 H), 7.32-7.37 (m, 3 H), 7.44 (dt, J ) 7.8, 1.5 Hz,
1 H), 7.53 (td, J ) 7.5, 1.5 Hz, 1 H), 7.59 (dd, J ) 7.2, 2.1 Hz,
2 H), 8.79 (ddd, J ) 4.8, 1.8, 1.2 Hz, 1 H); 13C NMR δ -2.8,
0.6, 1.1, 122.6, 127.7, 129.0, 129.5, 133.8, 134.2, 138.0, 150.0,
167.3; IR (neat) 1574, 1427, 1250, 1049 cm-1; HRMS (EI) m/z
calcd for C16H23NSi2 285.1369, found 285.1370.
Gen er a l Meth od s. Unless otherwise noted, all reactions
were carried out under argon atmosphere. Unless otherwise
noted, all materials were obtained from commercial suppliers
and used without further purification. Diethyl ether (Et2O) and
tetrahydrofuran (THF) were freshly distilled under argon from
(20) In the oxidation, an equimolar amount of pyridine, which is
derived from the pyridyl group on silicon, is formed. See ref 11b.

Deprotonation of a Methyl Group on Silicon
J . Org. Chem., Vol. 66, No. 11, 2001 3975
2-P yr id yld ip h en ylm eth ylsila n e (12): 1H NMR δ 0.91 (s,
3 H), 7.24 (ddd, J ) 7.5, 4.8, 1.5 Hz, 1 H), 7.33-7.41 (m, 6 H),
7.45 (dt, J ) 7.2, 1.2 Hz, 1 H), 7.54-7.60 (m, 5 H), 8.86 (ddd,
J ) 4.8, 1.8, 1.2 Hz, 1 H); 13C NMR δ -4.1, 122.9, 127.8, 129.4,
130.9, 134.0, 135.2, 135.3, 150.4, 164.7; IR (neat) 1427, 1113,
793, 731 cm-1; HRMS (EI) m/z calcd for C18H17NSi 275.1130,
found 275.1129.
[(2-P yr id yld ip h en ylsilyl)m eth yl]tr im eth ylsila n e (13):
1H NMR δ -0.17 (s, 9 H), 0.71 (s, 2 H), 7.20 (ddd, J ) 7.5, 4.8,
1.5 Hz, 1 H), 7.32-7.40 (m, 6 H), 7.46 (dt, J ) 7.5, 1.5 Hz, 1
H), 7.53 (td, J ) 7.5, 1.5 Hz, 1 H), 7.62-7.66 (m, 4 H), 8.84
(ddd, J ) 4.8, 1.8, 1.5 Hz, 1 H); 13C NMR δ -0.6, 1.2, 122.8,
127.7, 129.3, 130.9, 133.9, 135.6, 136.0, 150.1, 165.6; IR (neat)
1428, 1248, 1109, 835, 700 cm-1; HRMS (EI) m/z calcd for
[(2-P yr idyldim eth ylsilyl)m eth yl]tr ibu tylstan n an e (3e):
1H NMR δ -0.01 (s, J Sn-H ) 65.1 Hz, 2 H), 0.31 (s, 6 H), 0.70-
0.78 (m, 6 H), 0.85 (t, J ) 7.2 Hz, 9 H), 1.18-1.50 (m, 12 H),
7.15 (ddd, J ) 7.5, 5.1, 1.8 Hz, 1 H), 7.49 (dm, J ) 7.5 Hz, 1
H), 7.55 (td, J ) 7.5, 1.5 Hz, 1 H), 8.75 (dm, J ) 5.1 Hz, 1 H);
13C NMR δ -9.5, -0.5, 10.2, 13.5, 27.3, 29.0, 122.5, 128.6,
133.9, 150.1, 169.9; IR (neat) 1576, 1559, 1464, 1456, 1418,
1375, 1246, 1138 cm-1; HRMS (FAB) m/z calcd for C20H40
NSiSn (M + H)+ 440.1952, found 440.1955. Anal. Calcd for
20H39NSiSn: C, 54.55; H, 8.93; N, 3.18. Found: C, 54.39; H,
-
C
9.20; N, 3.25.
(2-P yr id yld im eth ylsilyl)m eth yl br om id e (3f): 1H NMR
δ 0.48 (s, 6 H), 2.75 (s, 2 H), 7.24 (ddd, J ) 7.5, 4.8, 1.5 Hz, 1
H), 7.55 (dt, J ) 7.5, 1.5 Hz, 1 H), 7.62 (td, J ) 7.5, 1.5 Hz, 1
H), 8.77 (ddd, J ) 4.8, 1.5, 1.2 Hz, 1 H); 13C NMR δ -4.3, 16.1,
123.3, 129.4, 134.1, 150.2, 164.5; IR (neat) 1576, 1250, 839
cm-1; HRMS (EI) m/z calcd for C8H12NSiBr 228.9922, found
228.9920.
C
21H25NSi2 347.1526, found 347.1534.
2-P yr id yl(ben zyl)d im eth ylsila n e (14): 1H NMR δ 0.31
(s, 6 H), 2.42 (s, 2 H), 6.97 (dm, J ) 7.5 Hz, 2 H), 7.02-7.09
(m, 1 H), 7.12-7.24 (m, 3 H), 7.40 (dm, J ) 7.5 Hz, 1 H), 7.55
(td, J ) 7.5, 1.5 Hz, 1 H), 8.82 (dm, J ) 5.1 Hz, 1 H); 13C NMR
δ -4.2, 24.8, 122.9, 124.1, 128.2, 128.3, 129.4, 134.0, 139.6,
150.2, 166.8; IR (neat) 1599, 1574, 1493, 1451, 1418, 1248,
1208 cm-1; HRMS (EI) m/z calcd for C14H17NSi 227.1130, found
227.1129. Anal. Calcd for C14H17NSi: C, 73.95; H, 7.54; N, 6.16.
Found: C, 74.05; H, 7.61; N, 6.10.
[(2-P yr id yld im eth ylsilyl)ben zyl]tr im eth ylsila n e (15):
1H NMR δ -0.13 (s, 9 H), 0.25 (s, 3 H), 0.47 (s, 3 H), 2.01 (s,
1 H), 6.94-7.03 (m, 3 H), 7.12-7.19 (m, 3 H), 7.38 (dt, J )
7.5, 1.5 Hz, 1 H), 7.52 (td, J ) 7.5, 1.5 Hz, 1 H), 8.78 (ddd,
J ) 4.5, 1.5, 1.2 Hz, 1 H); 13C NMR δ -2.14, -2.07, -0.2, 27.5,
122.7, 123.4, 128.0, 129.0, 129.4, 133.8, 142.2, 149.9, 167.5;
IR (neat) 1248, 1199, 1034 cm-1; HRMS (EI) m/z calcd for
(2-P yr id yld im eth ylsilyl)m eth yl iod id e (3g): 1H NMR
δ 0.48 (s, 6 H), 2.28 (s, 2 H), 7.23 (ddd, J ) 7.5, 4.8, 1.5 Hz, 1
H), 7.54 (dt, J ) 7.8, 1.5 Hz, 1 H), 7.61 (td, J ) 7.5, 1.5 Hz, 1
H), 8.77 (ddd, J ) 4.8, 1.5, 1.2 Hz, 1 H); 13C NMR δ -14.6,
-3.4, 123.3, 129.4, 134.1, 150.2, 164.9; IR (neat) 1574, 1419,
1248, 839 cm-1; HRMS (EI) m/z calcd for C8H12NSiI 276.9784,
found 276.9789.
2-P yr id yld im eth yl(3-bu ten yl)sila n e (3h ): 1H NMR δ
0.29 (s, 6 H), 0.86-0.94 (m, 2 H), 2.00-2.12 (m, 2 H), 4.83
(ddd, J ) 10.2, 4.8, 1.5 Hz, 1 H), 4.94 (ddd, J ) 17.1, 3.6, 1.5
Hz, 1 H), 5.82 (ddd, J ) 17.1, 10.2, 6.3 Hz, 1 H), 7.13 (ddd,
J ) 7.5, 4.8, 1.5 Hz, 1 H), 7.45 (ddd, J ) 7.5, 1.5, 1.2 Hz, 1 H),
7.53 (td, J ) 7.5, 1.8 Hz, 1 H), 8.74 (ddd, J ) 4.8, 1.8, 1.2 Hz,
1 H); 13C NMR δ -3.8, 13.7, 27.7, 112.9, 122.7, 129.0, 133.9,
C
17H25NSi2 299.1526, found 299.1525.
141.3, 150.2, 167.6; IR (neat) 1640, 1576, 1418, 1248 cm-1
;
[[2-P yr id yl(b e n zyl)m e t h ylsilyl]m e t h yl]t r im e t h ylsi-
HRMS (EI) m/z calcd for C11H17NSi 191.1130, found 191.1135.
2-P yr id yld im eth yl(p h en eth yl)sila n e (3i): 1H NMR δ
0.36 (s, 6 H), 1.20-1.27 (m, 2 H), 2.66-2.74 (m, 2 H), 7.10-
7.35 (m, 6 H), 7.50 (ddd, J ) 7.5, 1.5, 1.2 Hz, 1 H), 7.58 (td,
la n e (16): 1H NMR δ -0.10 (s, 9 H), 0.01 (d, J ) 13.8 Hz, 1
H), 0.18 (d, J ) 13.8 Hz, 1 H), 0.34 (s, 3 H), 2.36 (d, J ) 13.5
Hz, 1 H), 2.43 (d, J ) 13.5 Hz, 1 H), 6.87 (d, J ) 6.9 Hz, 2 H),
7.01-7.05 (m, 1 H), 7.10-7.16 (m, 2 H), 7.20 (ddd, J ) 7.5,
4.8, 1.5 Hz, 1 H), 7.33 (dt, J ) 7.8, 1.2 Hz, 1 H), 7.53 (td, J )
7.5, 1.8 Hz, 1 H), 8.80 (ddd, J ) 4.8, 1.8, 1.2 Hz, 1 H); 13C
NMR δ -3.8, 0.0, 1.2, 26.3, 122.8, 123.9, 128.0, 128.3, 129.5,
J ) 7.5, 1.5 Hz, 1 H), 8.81 (ddd, J ) 4.8, 1.5, 1.2 Hz, 1 H); 13
C
NMR δ -3.9, 16.7, 29.7, 122.7, 125.5, 127.8, 128.3, 129.1, 133.9,
144.9, 150.2, 167.4; IR (neat) 1574, 1495, 1453, 1418, 1246
cm-1; HRMS (EI) m/z calcd for C15H19NSi 241.1287, found
241.1281.
133.8, 139.6, 150.0, 166.9. IR (neat) 1493, 1250, 1049, 837 cm-1
;
HRMS (EI) m/z calcd for C17H25NSi2 299.1526, found 299.1520.
Rea ction s of 2 w ith Va r iou s Electr op h iles. In all cases,
2 was generated in situ by the procedure described above, and
the electrophiles were added to the solution of 2. Unless
otherwise noted, reactions were performed at -78 °C to room
temperature for several hours. Purification of the products was
done by acid-base extraction or by typical silica gel chroma-
tography.
[(2-P yr id yld im et h ylsilyl)m et h yl]d im et h ylp h en ylsi-
la n e (3b): 1H NMR δ 0.23 (s, 6 H), 0.27 (s, 6 H), 0.35 (s, 2 H),
7.16 (ddd, J ) 7.5, 4.8, 1.5 Hz, 1 H), 7.29-7.33 (m, 3 H), 7.42-
7.49 (m, 3 H), 7.54 (td, J ) 7.5, 1.8 Hz, 1 H), 8.76 (ddd, J )
4.8, 1.8, 1.2 Hz, 1 H); 13C NMR δ -1.1, -0.5, 1.1, 122.6, 127.7,
128.68, 128.71, 133.4, 134.0, 140.9, 150.1, 168.9; IR (neat) 3067,
2955, 1576, 1559, 1428, 1248, 1113 cm-1; HRMS (EI) m/z calcd
for C16H23NSi2 285.1369, found 285.1358.
Bis(2-p yr id yld im eth ylsilyl)m eth a n e (3c): 1H NMR δ
0.22 (s, 12 H), 0.38 (s, 2 H), 7.08 (ddd, J ) 7.5, 4.8, 1.5 Hz, 2
H), 7.38 (ddd, J ) 7.5, 1.5, 1.2 Hz, 2 H), 7.46 (td, J ) 7.5, 1.8
Hz, 2 H), 8.68 (ddd, J ) 4.8, 1.8, 1.2 Hz, 2 H); 13C NMR δ
-1.2, 0.1, 122.5, 128.6, 133.8, 150.0, 168.7; IR (neat) 2955,
1576, 1559, 1451, 1418, 1248, 1051 cm-1; HRMS (EI) m/z calcd
for C14H19N2Si2 (M - CH3)+ 271.1087, found 271.1079. Anal.
Calcd for C15H22N2Si2: C, 62.88; H, 7.74; N, 9.78. Found: C,
62.61; H, 7.78; N, 9.79.
2-P yr id yld im eth yl(4-p h en ylbu tyl)sila n e (3j): 1H NMR
δ 0.33 (s, 6 H), 0.86-0.94 (m, 2 H), 1.36-1.49 (m, 2 H), 1.60-
1.72 (m, 2 H), 2.60 (t, J ) 7.8 Hz, 2 H), 7.13-7.22 (m, 4 H),
7.23-7.30 (m, 2 H), 7.49 (ddd, J ) 7.5, 1.5, 1.2 Hz, 1 H), 7.57
(td, J ) 7.5, 1.8 Hz, 1 H), 8.80 (ddd, J ) 4.5, 1.8, 1.2 Hz, 1 H);
13C NMR δ -3.8, 14.5, 23.3, 35.1, 35.4, 122.7, 125.5, 128.2,
128.4, 129.1, 133.9, 142.8, 150.2, 167.9; IR (neat) 1576, 1454,
1246 cm-1; HRMS (EI) m/z calcd for C17H23NSi 269.1600, found
269.1609.
2-P yr idyldim eth yl(2-h ydr oxy-2-ph en yl)eth ylsilan e (3k):
1H NMR δ 0.27 (s, 3 H), 0.38 (s, 3 H), 1.39 (dd, J ) 14.7, 3.3
Hz, 1 H), 1.57 (dd, J ) 14.7, 10.2 Hz, 1 H), 5.05 (dd, J ) 10.2,
3.3 Hz, 1 H), 7.16-7.26 (m, 2 H), 7.31 (t, J ) 7.8 Hz, 2 H),
7.44 (d, J ) 7.8 Hz, 2 H), 7.54 (dm, J ) 7.8 Hz, 1 H), 7.63 (tm,
J ) 7.8 Hz, 1 H), 8.70 (dm, J ) 5.1 Hz, 1 H); 13C NMR δ -3.0,
-2.7, 28.1, 70.0, 123.1, 125.2, 126.4, 128.0, 129.3, 135.0, 148.0,
148.9, 166.5; IR (neat) 1580, 1455, 1420, 1250 cm-1; HRMS
(EI) m/z calcd for C15H19NOSi 257.1236, found 257.1226.
2-P yr idyldim eth yl(2-h ydr oxy-4-ph en yl)bu tylsilan e (3l):
1H NMR δ 0.32 (s, 3 H), 0.38 (s, 3 H), 1.12 (ddd, J ) 15.0, 3.0,
0.9 Hz, 1 H), 1.24 (dd, J ) 15.0, 10.2 Hz, 1 H), 1.72-2.00 (m,
2 H), 2.73 (ddd, J ) 13.5, 10.5, 6.0 Hz, 1 H), 2.89 (ddd, J )
13.5, 10.5, 5.7 Hz, 1 H), 3.93-4.04 (m, 1 H), 7.13-7.32 (m, 6
H), 7.55 (ddd, J ) 7.5, 2.4, 0.9 Hz, 1 H), 7.64 (tdd, J ) 7.5,
1.5, 0.9 Hz, 1 H), 8.09 (dm, J ) 4.8 Hz, 1 H); 13C NMR δ -2.9,
-2.2, 25.2, 32.5, 43.0, 67.1, 123.2, 125.5, 128.2, 128.5, 129.4,
[(2-P yr id yld im et h ylsilyl)m et h yl]t r im et h ylst a n n a n e
(3d ): 1H NMR δ 0.01 (s, J Sn-H ) 54.0 Hz, 9 H), 0.06 (s, 2 H),
0.31 (s, 6 H), 7.16 (ddd, J ) 7.5, 5.1, 1.8 Hz, 1 H), 7.49 (ddd,
J ) 7.5, 1.8, 1.5 Hz, 1 H), 7.56 (td, J ) 7.5, 1.8 Hz, 1 H), 8.75
(ddd, J ) 5.1, 1.8, 1.5 Hz, 1 H); 13C NMR δ -8.0, -6.4, -0.6,
135.0, 142.9, 149.0, 166.8; IR (neat) 1580, 1455, 1250 cm-1
;
HRMS (EI) m/z calcd for C17H23NOSi 285.1549, found 285.1551.
2-P yr id yld im et h yl(2-h yd r oxy-3-bu t en yl)sila n e (3m ):
1H NMR δ 0.32 (s, 3 H), 0.34 (s, 3 H), 1.15 (dd, J ) 14.7, 3.6
Hz, 1 H), 1.26 (dd, J ) 14.7, 9.9 Hz, 1 H), 4.35-4.44 (m, 1 H),
4.96 (ddd, J ) 10.5, 2.1, 1.5 Hz, 1 H), 5.19 (ddd, J ) 17.4, 1.8,
1.5 Hz, 1 H), 5.95 (ddd, J ) 17.4, 10.5, 6.0 Hz, 1 H), 7.21 (ddd,
122.5, 128.4, 133.8, 149.9, 169.3; IR (neat) 1576, 1246 cm-1
;
HRMS (FAB) m/z calcd for C11H22NSiSn (M + H)+ 316.0537,
found 316.0547.

3976 J . Org. Chem., Vol. 66, No. 11, 2001
Itami et al.
J ) 7.5, 4.8, 1.5 Hz, 1 H), 7.52 (ddd, J ) 7.5, 1.8, 1.5 Hz, 1 H),
7.62 (td, J ) 7.5, 1.5 Hz, 1 H), 8.64 (ddd, J ) 4.8, 1.8, 1.5 Hz,
1 H); 13C NMR δ -2.7, -2.0, 25.4, 68.9, 112.0, 123.1, 129.3,
as a colorless solid: 1H NMR δ 1.50-1.75 (m, 4 H), 2.25 (brs,
1 H), 2.64 (t, J ) 7.2 Hz, 2 H), 3.60 (t, J ) 6.3 Hz, 2 H), 7.00-
7.30 (m, 5 H); 13C NMR δ 27.3, 32.2, 35.7, 62.5, 125.7, 128.5,
128.6, 142.3.
1-P h en yl-1,2-eth a n ed iol (Ta ble 3, en tr y 2):22 1H NMR
δ 3.55 (dd, J ) 13.8, 8.4 Hz, 1 H), 3.63 (dd, J ) 13.8, 2.7 Hz,
1 H), 3.95 (brs, 1 H), 4.27 (brs, 1 H), 4.70 (dd, J ) 8.4, 2.7 Hz,
1 H), 7.20-7.30 (m, 5 H); 13C NMR δ 67.6, 74.6, 126.1, 127.8,
128.4, 140.5.
135.0, 144.2, 148.9, 166.4; IR (neat) 1580, 1420, 1250 cm-1
;
HRMS (EI) m/z calcd for C10H14NOSi (M - CH3)+ 192.0845,
found 192.0847.
2-P yr id yld im et h yl(2-h yd r oxy-2-p h en yl)p r op ylsila n e
(3n ): 1H NMR δ -0.26 (s, 3 H), 0.28 (s, 3 H), 1.64 (s, 3 H),
1.76 (s, 2 H), 7.10-7.23 (m, 2 H), 7.26 (tm, J ) 7.2 Hz, 2 H),
7.43 (dm, J ) 7.8 Hz, 1 H), 7.53 (dm, J ) 7.2 Hz, 2 H), 7.59
(tdm, J ) 7.8, 1.5 Hz, 1 H), 7.89 (brs, 1 H), 8.70 (dm, J ) 5.1
Hz, 1 H); 13C NMR δ -2.2, -1.2, 33.8, 35.0, 72.6, 123.1, 124.7,
125.8, 127.8, 129.4, 135.0, 148.6, 151.1, 167.1; IR (neat) 1580,
1445, 1250 cm-1; HRMS (EI) m/z calcd for C15H18NOSi (M -
CH3)+ 256.1158, found 256.1164.
4-P h en yl-1,2-bu ta n ed iol (Ta ble 3, en tr y 3):22 1H NMR
δ 1.65-1.85 (m, 2 H), 2.60-2.90 (m, 2 H), 3.40-3.55 (m, 3 H),
3.60-3.80 (m, 2 H), 7.15-7.25 (m, 3 H), 7.25-7.35 (m, 2 H);
13C NMR δ 31.7, 34.5, 66.6, 71.5, 126.0, 128.4, 128.5, 141.8.
2-P h en yl-1,2-p r op a n ed iol (Ta ble 3, en tr y 4):22 1H NMR
δ 1.48 (s, 3 H), 2.78 (brs, 1 H), 3.21 (brs, 1 H), 3.56 (d, J )
11.1 Hz, 1 H), 3.71 (d, J ) 11.1 Hz, 1 H), 7.22-7.45 (m, 5 H);
13C NMR δ -0.7, 22.8, 25.6, 31.2, 41.4, 70.3, 123.0, 129.5, 134.9,
148.9, 167.6.
1-[(2-P yr id yld im eth ylsilyl)m eth yl]cycloh exa n ol (3o):
1H NMR δ 0.30 (s, 6 H), 1.18-1.50 (m, 6 H), 1.30 (s, 2 H),
1.55-1.72 (m, 4 H), 6.53 (brs, 1 H), 7.18 (ddd, J ) 7.2, 5.1, 1.5
Hz, 1 H), 7.51 (ddd, J ) 7.8, 1.5, 1.2 Hz, 1 H), 7.60 (ddd, J )
1-(Hyd r oxym eth yl)cycloh exa n ol (Ta ble 3, en tr y 5):4
1H NMR δ 1.20-1.70 (m, 10 H), 2.67 (brs, 1 H), 3.10 (brs, 1
H), 3.41 (s, 2 H); 13C NMR δ 21.7, 25.8, 33.9, 69.9, 71.9.
7.8, 7.2, 1.8 Hz, 1 H), 8.64 (ddd, J ) 5.1, 1.8, 1.2 Hz, 1 H); 13
C
NMR δ -0.7, 22.8, 25.6, 31.2, 41.4, 70.3, 123.0, 129.5, 134.9,
148.9, 167.6; IR (neat) 1578, 1453, 1420, 1248 cm-1; HRMS
(EI) m/z calcd for C14H23NOSi 249.1549, found 249.1551.
Ack n ow led gm en t. This research was supported by
a Grant-in-Aid for Scientific Research from the Ministry
of Education, Science, Sports, and Culture, J apan, and
the Mitsubishi Foundation. K.M. thanks the J apan
Society for the Promotion of Science for Young Scien-
tists.
Typ ica l P r oced u r e for H2O2 Oxid a tion (Ta ble 3, En tr y
1). To a mixture of KF (24 mg, 0.41 mmol) and KHCO3 (41
mg, 0.41 mmol) in MeOH (1 mL) and THF (1 mL) was added
3j (55 mg, 0.20 mmol) and then aqueous 30% H2O2 (0.70 g,
6.12 mmol). The mixture was stirred at 50 °C for 6 h. After
being cooled at room temperature, the reaction mixture was
treated with water (10 mL). The mixture was extracted with
Et2O (4 × 10 mL), and the combined organic phase was washed
successively with 15% aqueous Na2S2O3 (10 mL). Drying over
MgSO4 and subsequent silica gel chromatography (hexane/
EtOAc ) 1/1 to 1/2) afforded 4-phenylbutanol21 (30 mg, 96%)
Su p p or tin g In for m a tion Ava ila ble: 13C NMR spectra for
compounds 3b,d ,f-o, 9, 11-13, 15, and 16. This material is
available free of charge via the Internet at http://pubs.acs.org.
J O015528G
(21) Guennouni, N.; Lhermitte, F.; Cochard, S.; Carboni, B. Tetra-
hedron 1995, 51, 6999.
(22) Kobayashi, S.; Endo, M.; Nagayama, S. J . Am. Chem. Soc. 1999,
121, 11229.