Catalytic nucleophilic addition reaction to (2-furyl)carbene intermediates generated from carbonyl-ene-ynes

Article abstract of DOI:10.1246/bcsj.81.1158

Rhodium- and chromium-catalyzed addition reactions of various σ-bonds, such as C-H, N-H, O-H, Si-H, and S-H bonds, to (2-furyl)carbenoids in situ generated from conjugated carbonyl-ene-yne compounds having electron-withdrawing groups on an alkyne terminus are described, 2-Alkoxy-2,5-dihydrofuran was obtained from the chromium-catalyzed addition reaction of an alcohol with the (2-furyl)carbene chromium intermediates in a conjugate manner.

Full text of DOI:10.1246/bcsj.81.1158

1158 Bull. Chem. Soc. Jpn. Vol. 81, No. 9, 1158–1165 (2008)
ꢀ 2008 The Chemical Society of Japan
Catalytic Nucleophilic Addition Reaction to (2-Furyl)carbene
Intermediates Generated from Carbonyl–Ene–Ynes
ꢀ
Koji Miki, Yumiko Kato, Sakae Uemura, and Kouichi Ohe
Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering,
Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510
Received April 14, 2008; E-mail: ohe@scl.kyoto-u.ac.jp
Rhodium- and chromium-catalyzed addition reactions of various ꢀ-bonds, such as C–H, N–H, O–H, Si–H,
and S–H bonds, to (2-furyl)carbenoids in situ generated from conjugated carbonyl–ene–yne compounds having
electron-withdrawing groups on an alkyne terminus are described. 2-Alkoxy-2,5-dihydrofuran was obtained from the
chromium-catalyzed addition reaction of an alcohol with the (2-furyl)carbene chromium intermediates in a conjugate
manner.
Nucleophilic addition reactions of either activated or inacti-
R
O
R
O
R
vated ꢀ-bonds, such as C–H, N–H, O–H, Si–H, and S–H bonds
to transient electrophilic carbenoid species serve as one of the
most powerful ꢀ-bond construction reactions.1 Transition-met-
al-catalyzed intra- and intermolecular addition reactions to a
C=M bond of carbenoid species generated from diazo com-
pounds have been intensively investigated to provide a direct
entry to ꢀ-bond construction.2–7 We, and other researchers,
have explored the generation of carbenoid species with activa-
tion of alkynes using transition-metal complexes.8 We have al-
ready developed catalytic carbene-transfer reactions involving
the in situ generation of (2-furyl)carbenoids from carbonyl–
ene–yne compounds and their application to catalytic cyclo-
propanation reactions and the Doyle–Kirmse reaction, which
is a formal C–S bond insertion reaction via an ylide rearrange-
ment (Schemes 1a and 1b).8b,8c,9 In the course of our continu-
ous study, we have also found that electron-withdrawing
groups introduced at the alkyne terminus of 1 enhance the
electrophilicity of the intermediary carbenoid species.9,10
Herein, we report on rhodium-catalyzed nucleophilic addition
reactions of Xsp3–H bonds (where X ¼ C, N, O, S, and Si),
as well as a unique chromium-catalyzed addition reaction to
the intermediary (2-furyl)carbene complexes with methanol
(Scheme 1c).
R1
− [M]
cat. [M]
O
O
(a)
(b)
R1
[M]
[M]
H
H
H
1
cyclopropanation
H
SR2
O
O
cat. [M]
SR2
− [M]
EWG
EWG
EWG
Doyle-Kirmse Reaction
1
O
X
H
H
EWG
1,1-addition
O
cat. [M]
O
X H
− [M]
(c)
[M]
X
EWG
EWG
O
1
A
H
EWG
conjugate addition
(X = R3C, R2N, RO, RS, R3Si)
Scheme 1.
Results and Discussion
Rhodium-Catalyzed Addition Reactions of C–H Bonds.
First, we attempted to carry out the addition reaction of a C–
H bond of cyclohexa-1,4-diene to a (2-furyl)carbene inter-
mediate generated from the carbonyl–ene–yne compound 1a,
which is a good (2-furyl)carbene precursor for the catalytic
cyclopropanation reaction,8b,8c in the presence of a catalytic
amount of [Rh2(OAc)4]. However, no reaction occurred. On
the other hand, when the rhodium-catalyzed reaction of 1b
having an electron-withdrawing benzoyl group at an alkyne
terminus, which was expected to enhance the electrophilicity
of the intermediary carbenoid species to an allylic C–H bond
was carried out, 3-furfurylcyclohexa-1,4-diene derivative 2b
was obtained in 20% yield (eq 1). The acetyl compound 1c
was more reactive for the allylic C–H bond addition reaction
and afforded the corresponding product 2c in 35% yield. No-
tably, the reaction of 1d having a methoxycarbonyl moiety
with cyclohexa-1,4-diene took place at room temperature.
Moreover, 1e, which has a phenoxycarbonyl moiety, reacted
with cyclohexa-1,4-diene more smoothly to give the corre-
sponding adduct 2e in higher yield. The results of the addition
reactions using 1e with selected compounds are summarized in
Table 1. Cyclohexa-1,3-diene gave the adduct 3e with an allyl-
ic C–H bond of cyclohexa-1,3-diene in 47% yield as a mixture
of diastereomers (dr = 80/20). Cycloheptatriene also reacted
Published on the web September 11, 2008; doi:10.1246/bcsj.81.1158

K. Miki et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 9 (2008) 1159
Table 1. Rh-Catalyzed Addition Reactions of sp3 C–H
Bond to Carbenes Generated from 1ea)
Table 2. Rh-Catalyzed Addition Reactions of Alcohols or
Phenols with 1da)
2.5 mol%
[Rh2(OAc)4]
2.5 mol%
O
O
[Rh2(OAc)4]
ROH
+
1d
+
R
H
OR
H
1e
R-H
(10 equiv)
CH2Cl2, rt
CH2Cl2, rt
(2 equiv)
PhO2C
O
MeO2C
Entry
ROH
Time/h
Product
Yield/%b)
O
O
1
2
3
4
5
6
7
8
MeOH
EtOH
BnOH
iPrOH
tBuOH
PhOH
4
4
4
6d
7d
8d
9d
—
—
—
10d
82
63
42
54
O
H
H
H
PhO2C
PhO2C
3e 47% (80/20)
PhO2C
5e 68% (67/33)
4e 38%
4
12
12
12
8
—
a) Reactions of 1e (0.2 mmol) with cyclic olefin (2.0 mmol) in
CH2Cl2 (1 mL) were carried out in the presence of [Rh2(OAc)4]
(0.005 mmol) at room temperature under N2. Diastereomeric
trace
—
p-MeOC6H4OH
p-NO2C6H4OH
44
1
ratios were determined by H NMR.
a) Reactions of 1d (0.2 mmol) with alcohol or phenol
(0.4 mmol) in CH2Cl2 (1 mL) were carried out in the presence
of [Rh2(OAc)4] (0.005 mmol) at room temperature under N2.
b) Isolated yield.
R
2.5 mol%
O
O
[Rh2(OAc)4]
+
ð1Þ
CH2Cl2, reflux
R
R'
(10 equiv)
Table 3. Rh-Catalyzed Addition Reactions of N–H Bond to
Furylcarbene Species Using 1da)
1a (R = Ph, R' = H)
2a 0% (24 h)
2b 20% (72 h)
2c 35% (8 h)
2d 57% (rt, 48 h)
2e 67% (rt, 12 h)
1b (R = H, R' = COPh)
1c (R = H, R' = COMe)
1d (R = H, R' = CO2Me)
1e (R = H, R' = CO2Ph)
2.5 mol%
[Rh2(OAc)4]
O
RR'NH
+
1d
NRR'
H
CH2Cl2, rt, 6 h
(2 equiv)
MeO2C
with 1e to give the cyclohepta-2,4,6-trienyl adduct 4e in 38%
yield. The reaction with 2,5-dihydrofuran also produced the
adduct 5e in 68% yield as a mixture of diastereomers
(dr = 67/33). However, no addition reaction of a C–H bond
occurred with cyclohexene, tetrahydrofuran, cyclopenta-
diene,11 or penta-1,4-diene. These results indicate that highly
activated C–H bonds at a doubly allylic position, or at an allyl-
ic position adjacent to a heteroatom in a cyclic structure are
required for the nucleophilic addition reactions using 1e as a
furylcarbene precursor. Davies and co-workers reported that
phenylcarbene intermediates in situ generated from phenyldi-
azoacetates inserted into C–H bonds at a double allylic posi-
tion as well as at a C–H bond of cyclohexane.3c They men-
tioned that a C–H bond at a double allylic position of cyclo-
hexa-1,4-diene is almost 10 times as reactive to a carbene
intermediate than a C–H bond next to the oxygen atom of
tetrahydrofuran. Since an electron-rich furan ring generated
from a carbonyl–ene–yne moiety decreases the electrophilicity
of a (2-furyl)carbene carbon to attack C–H bonds, it seems that
phenylcarbene intermediates generated from phenyldiazoace-
tates are much more reactive than the present (2-furyl)carbe-
noid generated from 1e in the addition reactions to C–H bonds.
Rhodium-Catalyzed Addition Reactions of Heteroatom–
Hydrogen Bonds (X–H, where X ¼ N, O, Si, or S). Addi-
tion reactions of alcohols or phenols to carbenoid species gen-
erated from diazoalkanes have been well investigated.4 There-
fore, we carried out the rhodium-catalyzed addition reaction of
several alcohols and phenols with methoxycarbonyl analogue
1d as a furylcarbene precursor. The results are shown in
Table 2. The reaction of 1d with methanol gave the furfuryl
methyl ether 6d in 82% yield (Entry 1). Reactions of 1d with
ethanol and benzyl alcohol also gave the corresponding fur-
Entry
RR0NH
Product
Yield/%b)
1
2
3
4
5
6
7
8
Et2NH
—
—
69
45
46
12
62
—
51
Ph(Me)NH
Ph2NH
PhNH2
p-MeOC6H4NH2
p-NO2C6H4NH2
CH3CONH2
TsNH2
11d
12d
13d
14d
15d
—
16d
a) Reactions of 1d (0.2 mmol) with amine or amide (0.4 mmol)
in CH2Cl2 (1 mL) were carried out in the presence of
[Rh2(OAc)4] (0.005 mmol) at room temperature under N2. b)
Isolated yield.
furyl ethers 7d and 8d in 63% and 42% yields, respectively
(Entries 2 and 3). Secondary alcohol also reacted with 1d to
give the adduct 9d in 54% yield (Entry 4). However, no reac-
tion occurred with tert-butyl alcohol, probably because of its
bulkiness (Entry 5). The reaction with phenol and p-methoxy-
phenol gave a complex mixture, while the reaction with p-
nitrophenol produced the adduct 10d in 44% yield (Entries
6–8). These are unexpected results, because it is known that
electrophilic carbene complexes generated from diazo com-
pounds react with more electron-rich phenols smoothly to give
adducts.4i
To examine the addition reactions of heteroatom–hydrogen
bonds, the reaction of 1d with several amines and amides
was carried out,5 and the results are summarized in Table 3.
Although several researchers have reported that alkyl amines
are applicable to the addition reaction of phenylcarbenoids
generated from phenyldiazoacetates,5c,5d the reaction of 1d

1160 Bull. Chem. Soc. Jpn. Vol. 81, No. 9 (2008)
Catalytic Insertion Reactions of Carbenoids
with diethylamine gave no adduct (Entry 1). On the other
hand, N-methylaniline and diphenylamine gave ꢁ-amino acid
esters 11d and 12d in 69% and 45% yields, respectively (En-
tries 2 and 3). The carbene precursor 1d underwent an addition
reaction to only one of two N–H bonds of anilines to give 13d
(Entry 4). These results indicate that at least one aryl group on
the nitrogen atom is essential for the present addition reactions
of N–H bonds to (2-furyl)carbene intermediates. p-Methoxy-
aniline gave the corresponding ꢁ-amino acid ester 14d in a
lower yield, while p-nitroaniline afforded 15d in a higher yield
(Entries 5 and 6). The propensity of the reactivity of p-substi-
tuted anilines was consistent with that of phenol derivatives
(vide supra). The reaction with acetamide gave no adduct,
while the reaction with p-toluenesulfonamide yielded the cor-
responding adduct 16d in a moderate yield (Entries 7 and 8).
A competition experiment, in which 2-anilinoethanol with
1d was reacted at room temperature, led exclusively to the for-
mation of N-adducts 17d and N-phenylmorpholin-2-one 18d
(eq 2).12 This tendency, where a (2-furyl)carbenoid intermedi-
ate favors a nitrogen nucleophile rather than an oxygen nucleo-
phile, is similar to the reported result of the competition
reaction of diazo compounds with aniline and phenol to give
2-phenylaminoacetates in rhodium catalysis.4e
2.5 mol%
[Rh2(OAc)4]
O
SR
H
ð4Þ
RSH
(2 equiv)
+
1d
CH2Cl2, rt
MeO2C
R = n-Bu
21d 35% (24 h)
22d 59% (8 h)
23d 73% (8 h)
24d 80% (4 h)
Ph
p-MeOC6H4
p-NO2C6H4
Chromium-Catalyzed Conjugate Addition Reactions of
Alcoholic O–H Bonds. Since we found the generation of
(2-furyl)carbene complexes from carbonyl–ene–ynes and a
chromium carbonyl compound,8a–8c we attempted to carry
out the addition reactions of an alcohol in the presence of chro-
mium catalyst. The reaction of 1a with MeOH (2 equiv) in
THF was carried out at room temperature in the presence of
5 mol % of [Cr(CO)5(THF)], but no adducts were obtained
(eq 5). On the other hand, the reaction of the carbonyl–ene–
yne compound 1b afforded the unexpected 2-alkoxy-5-alkyli-
dene-2,5-dihydrofuran 25b in 38% yield instead of the typical
adduct 26b (Scheme 2).13 Barluenga and co-workers reported
that the nucleophilic conjugate addition reactions of organo-
lithium reagents to Fischer carbene complexes led to the for-
mation of 2,3-dihydrofurans.14,15 To the best of our knowl-
edge, the present reaction is the first example of the conjugate
addition of methanol to arylcarbene complexes. Among the
other solvents examined for this chromium-mediated conju-
gate addition reaction, benzene was revealed to be the best sol-
vent of choice (69% yield). Secondary alcohols were less reac-
tive under identical conditions, giving the corresponding ad-
ducts in 10%–20% yields, while tert-butyl alcohol gave no ad-
ducts at all. Interestingly, adduct 25b was gradually isomerized
into thermodynamically stable 25b0 at room temperature under
slightly acidic conditions (eq 6).13 This indicates that the more
hindered chromium moiety rather than the benzoyl group is
oriented towards the less hindered oxygen in order to avoid
steric repulsion from the cyclohexane ring in intermediate B
and transient structure C.
2.5 mol%
[Rh2(OAc)4]
Ph
OH
(2 equiv)
ð2Þ
+
1d
N
CH2Cl2
H
O
O
H Ph
N
+
H
OH
N
MeO2C
17d
O
Ph
O
18d
temp. time/h 17d
18d
rt
6
90%
6%
reflux
19
31% 17%
Finally, we examined the addition reactions of Si–H and S–
H bonds with 1d in the presence of a Rh catalyst. Since silanes
are known as good acceptors of carbene intermediates generat-
ed from diazoalkanes,6 the reactions of 1d with triethylsilane
or triphenylsilane were carried out. Expectedly, the rhodium-
catalyzed addition reaction proceeded to give 19d (67% yield)
and 20d (20% yield), respectively (eq 3). Reactions of 1d with
alkanethiol and benzenethiol gave sulfides 21d (35% yield)
and 22d (59% yield), respectively (eq 4). To the best of our
knowledge, only a few catalytic addition reactions of S–H
bonds to carbene species generated from diazoalkanes have
been reported.7 Interestingly, arenethiols gave the correspond-
ing adducts 23d and 24d in good yields, irrespective of the
electronic nature of the substituents.
Ph
5 mol%
[Cr(CO)5(THF)]
O
N. R.
MeOH
ð5Þ
THF, rt, 24 h
(2 equiv)
1a
OMe
O
30 mol%
[Cr(CO)5(THF)]
CHO
MeOH
rt, 1 h
(2 equiv)
Bz
1b
Bz
25b (38% in THF)
25b (69% in benzene)
Me
Bz
MeOH
MeOH
[Cr]
O H
O
5
4
3
2.5 mol%
[Rh2(OAc)4]
O
O
O
X
SiR3
H
X 2
ð3Þ
R3SiH
(2 equiv)
+
1d
1
[Cr]
OMe
MeOH
CH2Cl2, rt
MeO2C
Bz
Bz
B
C
26b
R = Et 19d 67% (2 h)
20d 20% (8 h)
Ph
Scheme 2.

K. Miki et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 9 (2008) 1161
a flame dried Schlenk flask was added [Rh2(OAc)4] (2.2 mg,
0.005 mmol) at room temperature under N2. After the reaction
was complete, the organic solvent was removed under reduced
pressure, and the residue was subjected to column chromatogra-
phy on SiO2 with hexane/AcOEt (v/v = 20/1) as an eluent to
afford the corresponding products.
OMe
O
ð6Þ
25b
CDCl3, rt
Bz
25b'
3-Furfurylcyclohexa-1,4-diene 2b. A colorless oil (12.5 mg,
0.039 mmol, 20% yield); IR (neat) 544, 599, 699, 759, 800, 1026,
1094, 1260, 1446, 1596, 1681, 1773 (C=O), 2817, 2853, 2921,
In conclusion, we have demonstrated the rhodium- and
chromium-catalyzed addition reactions of various ꢀ-bonds,
such as C–H, N–H, O–H, Si–H, and S–H, based on the in situ
generation of (2-furyl)carbenoids from conjugated carbonyl–
ene–yne compounds. We also found that carbonyl–ene–yne
compounds having electron-withdrawing groups on an alkyne
terminus act as a strongly electrophilic carbenoid precursor for
Rh- and Cr-catalyzed reactions. In the case of chromium-cata-
lyzed reactions, the addition of an alcohol to the (2-furyl)car-
bene chromium intermediates takes place in a conjugate man-
ner to afford 2-alkoxy-5-alkylidene-2,5-dihydrofuran. These
results strongly support the generation of (2-furyl)carbene
species from conjugated carbonyl–ene–ynes. These nucleo-
philic addition reactions of O–H, N–H, O–H, Si–H, and S–H
ꢀ-bonds to carbene complex intermediates will be applicable
to asymmetric synthesis.
1
3028, 3400, 2855, 2931, 3073 cmꢃ1; H NMR (400 MHz, CDCl3,
25 ꢁC) ꢂ 1.60–1.62 (m, 4H), 2.35–2.56 (m, 4H), 2.65–2.70 (m,
2H), 3.83–3.86 (m, 1H), 4.51 (d, J ¼ 10:8 Hz, 1H), 5.36 (d, J ¼
10:8 Hz, 1H), 5.67–5.77 (m, 3H), 7.07 (s, 1H), 7.41 (dd, J ¼
7:2, 7.2 Hz, 2H), 7.50 (t, J ¼ 7:2 Hz, 1H), 7.95 (d, J ¼ 7:2 Hz,
2H); 13C NMR (100 MHz, CDCl3, 25 ꢁC) ꢂ 20.2, 20.6, 23.0,
23.2, 26.4, 35.4, 53.0, 119.3, 122.4, 125.5, 125.6, 126.6, 127.1,
128.4, 128.4, 132.8, 136.6, 136.9, 142.5, 195.3. HRMS (FAB)
Calcd for C22H23O2 (M þ Hþ): 319.1698. Found: 319.1698.
3-Furfurylcyclohexa-1,4-diene 2c. A yellow oil (31.3 mg,
0.070 mmol, 35% yield); IR (neat) 402, 701, 742, 791, 849,
1112, 1152, 1260, 1353, 1416, 1443, 1556, 1634, 1722 (C=O),
2857, 2954, 3029, 3428 cmꢃ1
;
1H NMR (400 MHz, CDCl3,
25 ꢁC) ꢂ 1.59–1.67 (m, 4H), 2.08 (s, 3H), 2.41–2.44 (m, 2H),
2.50–2.53 (m, 2H), 2.59–2.63 (m, 2H), 3.56–3.58 (m, 2H), 5.32
(d, J ¼ 10:0 Hz, 1H), 5.67–5.70 (m, 2H), 5.75–5.78 (m, 1H),
7.10 (s, 1H); 13C NMR (100 MHz, CDCl3, 25 ꢁC) ꢂ 20.2, 20.4,
23.1, 23.2, 26.3, 29.3, 34.7, 58.4, 119.7, 122.3, 125.4, 125.7,
126.3, 126.8, 136.6, 142.8, 204.5. Anal. Calcd for C17H20O2: C,
74.97; H, 7.40%. Found: C, 74.48; H, 7.62%. HRMS (FAB) Calcd
for C17H21O2 (M þ Hþ): 257.1542. Found: 257.1547.
Experimental
General Procedures. Analytical thin-layer chromatographies
(TLC) were performed with silica gel 60 Merck F-254 plates. Col-
umn chromatographies were performed with Merck silica gel 60.
NMR spectra were measured for solutions in CDCl3 with SiMe4
as an internal standard or CD2Cl2 (1H and 13C): the following ab-
breviations are used; s: singlet, d: doublet, t: triplet, q: quartet, m:
multiplet. IR spectra were recorded with an FT-IR spectrometer.
Melting points are uncorrected. High-resolution mass spectra
(FAB HRMS) and low-resolution mass spectra (FAB LRMS)
were obtained with JEOL, JMX-SX 102A spectrometer. Elemen-
tal analyses were performed at Microanalytical Center of Kyoto
University. All new compounds prepared were fully characterized.
Tetrahydrofuran (THF) was distilled from sodium benzophenone
ketyl under argon, and other solvents were dried by the usual
methods and distilled before use.
3-Furfurylcyclohexa-1,4-diene 2d. A colorless oil (31.3 mg,
0.11 mmol, 57% yield); IR (neat) 608, 708, 738, 761, 889, 919,
989, 1020, 1113, 1155, 1255, 1321, 1384, 1434, 1556, 1635,
1
1739 (C=O), 2855, 2931, 3028, 3478 cmꢃ1; H NMR (400 MHz,
CDCl3, 25 ꢁC) ꢂ 1.65–1.68 (m, 4H), 2.45–2.50 (m, 4H), 2.62–
2.64 (m, 2H), 3.57–3.59 (m, 1H), 3.70 (s, 3H), 5.33–5.36 (m,
1H), 5.67–5.73 (m, 2H), 5.78–5.82 (m, 1H), 7.10 (s, 1H);
13C NMR (100 MHz, CDCl3, 25 ꢁC) ꢂ 20.2, 20.3, 23.1, 23.2,
26.3, 35.9, 50.5, 52.0, 119.2, 122.1, 125.7, 125.8, 126.1, 126.3,
136.3, 142.7, 171.0. HRMS (FAB) Calcd for C17H21O3
(M þ Hþ): 273.1491. Found: 273.1488.
Synthesis of 1. Compounds 1a–1d were prepared by reported
procedures.9
3-Furfurylcyclohexa-1,4-diene 2e. A colorless oil (44.9 mg,
0.13 mmol, 67% yield); IR (neat) 689, 707, 739, 942, 1024, 1070,
1123, 1162, 1193, 1318, 1492, 1592, 1637, 1758 (C=O), 2857,
Ene–Yne–Carbonyl Compound 1e. Ene–yne–carbonyl com-
pound 1e was prepared by the same procedure for the synthesis of
1d9 using phenyl chloroformate instead of methyl chloroformate
to introduce a phenyloxycarbonyl moiety at an alkyne terminus.
A yellow solid (0.52 g, 2.04 mmol, 68% yield for 2 steps); mp
53.8–54.0 ꢁC; IR (KBr) 495, 694, 733, 758, 846, 939, 1063,
1127, 1161, 1215, 1254, 1366, 1426, 1455, 1491, 1588, 1682
(C=O), 1720 (C=O), 2215 (CꢂC), 2840, 2864, 2939, 3062,
2932, 3030, 3450 cmꢃ1
;
1H NMR (400 MHz, CDCl3, 25 ꢁC)
ꢂ 1.68–1.70 (m, 4H), 2.51–2.53 (m, 4H), 2.67 (dd, J ¼ 4:0,
4.0 Hz, 2H), 3.66–3.73 (m, 1H), 3.76 (d, J ¼ 10:0 Hz, 1H),
5.43–5.45 (m, 1H), 5.75–5.78 (m, 1H), 5.84–5.87 (m, 2H), 7.04
(d, J ¼ 7:2 Hz, 2H), 7.14 (s, 1H), 7.20 (t, J ¼ 7:2 Hz, 1H), 7.34
(dd, J ¼ 7:2, 7.2 Hz, 2H); 13C NMR (100 MHz, CDCl3, 25 ꢁC)
ꢂ 20.2, 20.4, 23.2, 23.2, 26.4, 36.0, 50.7, 119.5, 121.4, 122.2,
125.6, 125.7, 125.9, 126.1, 126.4, 129.2, 136.6, 142.3, 150.6,
168.9. Anal. Calcd for C22H22O3: C, 79.02; H, 6.63%. Found:
C, 79.09; H, 6.84%.
3346, 3441 cmꢃ1 1H NMR (300 MHz, CDCl3, 25 ꢁC) ꢂ 1.60–
;
1.81 (m, 4H), 2.25–2.38 (m, 2H), 2.43–2.55 (m, 2H), 7.15 (d,
J ¼ 7:2 Hz, 2H), 7.27 (t, J ¼ 7:2 Hz, 1H), 7.41 (dd, J ¼ 7:2,
7.2 Hz, 2H), 10.1 (s, 1H); 13C NMR (75 MHz, CDCl3, 25 ꢁC)
ꢂ 20.5, 21.4, 22.3, 31.0, 84.4, 87.5, 121.2, 126.5, 129.5, 135.2,
148.4, 149.9, 151.5, 191.2. Anal. Calcd for C16H14O3: C, 75.57;
H, 5.55%. Found: C, 75.12; H, 5.58%. HRMS (FAB) Calcd for
C16H15O3 (M þ Hþ): 255.1021. Found: 255.1024.
4-Furfurylcyclohexa-1,3-diene 3e. A colorless oil (31.4 mg,
0.093 mmol, 47% yield, dr = 80/20); IR (neat) 411, 502, 689,
734, 1024, 1094, 1118, 1384, 1441, 1493, 1593, 1748 (C=O),
2851, 2925, 3040, 3412 cmꢃ1
;
1H NMR (400 MHz, CD2Cl2,
25 ꢁC): major isomer, ꢂ 1.67–1.74 (m, 4H), 1.89 (ddd, J ¼ 5:2,
6.4, 17.6 Hz, 1H), 2.19–2.20 (m, 1H), 2.50–2.56 (m, 4H), 3.10–
3.18 (m, 1H), 3.98 (d, J ¼ 10:8 Hz, 1H), 5.76 (dd, J ¼ 4:8,
9.6 Hz, 1H), 5.95–6.00 (m, 2H), 6.07 (dd, J ¼ 4:8, 9.6 Hz, 1H),
Typical Procedure for Rh-Catalyzed Reaction of 1 with
Allylic C–H Bonds. To a solution of 1 (0.20 mmol) and diene
or triene (2 mmol) in dry and deoxygenated CH2Cl2 (1.0 mL) in

1162 Bull. Chem. Soc. Jpn. Vol. 81, No. 9 (2008)
Catalytic Insertion Reactions of Carbenoids
7.01 (d, J ¼ 7:6 Hz, 2H), 7.16 (s, 1H), 7.23 (t, J ¼ 7:6 Hz, 1H),
7.37 (dd, J ¼ 7:6, 7.6 Hz, 2H); minor isomer, ꢂ 1.67–1.74 (m,
4H), 2.21–2.23 (m, 1H), 2.45–2.56 (m, 5H), 3.22–3.31 (m, 1H),
3.96 (d, J ¼ 10:8 Hz, 1H), 5.50 (dd, J ¼ 4:0, 8.8 Hz, 1H), 5.85–
5.89 (m, 1H), 5.95–5.97 (m, 2H), 7.03 (d, J ¼ 7:6 Hz, 2H), 7.16
(s, 1H), 7.23 (t, J ¼ 7:6 Hz, 1H), 7.37 (dd, J ¼ 7:6, 7.6 Hz, 2H);
13C NMR (100 MHz, CD2Cl2, 25 ꢁC): major isomer, ꢂ 20.7,
20.7, 23.6, 23.6, 25.9, 33.2, 46.8, 121.8, 122.0, 122.7, 124.3,
125.5, 125.7, 126.0, 128.2, 129.6, 136.9, 142.9, 151.1, 169.7;
minor isomer, ꢂ 20.5, 20.5, 23.5, 23.5, 27.5, 33.6, 47.1, 121.8,
121.9, 123.1, 124.5, 125.5, 125.9, 126.2, 127.8, 129.7, 136.5,
143.2, 151.6, 169.8. Anal. Calcd for C22H22O3 (a mixture of
isomers): C, 79.02; H, 6.63%. Found: C, 78.95; H, 6.88%.
25 ꢁC) ꢂ 15.0, 20.0, 20.1, 22.9, 22.9, 52.4, 64.8, 73.0, 121.3,
122.2, 137.3, 142.2, 169.4. Anal. Calcd for C13H18O4: C, 65.53;
H, 7.61%. Found: C, 65.76; H, 7.69%.
Benzyl Furfuryl Ether 8d.
A colorless oil (25.2 mg,
0.084 mmol, 42% yield); IR (neat) 401, 699, 747, 934, 1026,
1093, 1204, 1263, 1384, 1435, 1681, 1739 (C=O), 2339, 2359,
2859, 2932, 3458 cmꢃ1
;
1H NMR (300 MHz, CDCl3, 25 ꢁC)
ꢂ 1.59–1.66 (m, 4H), 2.30–2.37 (m, 1H), 2.46–2.50 (m, 3H),
3.76 (s, 3H), 4.52 (d, J ¼ 12:0 Hz, 1H), 4.62 (d, J ¼ 12:0 Hz,
1H), 4.97 (s, 1H), 7.12 (s, 1H), 7.25–7.34 (m, 5H); 13C NMR
(75 MHz, CDCl3, 25 ꢁC) ꢂ 19.9, 20.0, 22.8, 22.8, 52.4, 70.7,
71.6, 121.9, 122.3, 127.8, 128.0, 128.3, 137.0, 137.6, 142.0,
169.3. Anal. Calcd for C18H20O4: C, 71.98; H, 6.71%. Found:
C, 71.70; H, 6.77%.
7-Furfurylcyclohepta-1,3,5-triene 4e.
A colorless oil
(26.2 mg, 0.076 mmol, 38% yield); IR (neat) 500, 701, 742, 935,
1023, 1070, 1123, 1162, 1195, 1243, 1399, 1441, 1492, 1592,
Furfuryl i-Propyl Ether 9d.
A colorless oil (27.0 mg,
0.11 mmol, 54% yield); IR (neat) 601, 667, 758, 919, 990, 1019,
1090, 1174, 1197, 1264, 1384, 1435, 1633, 1760 (C=O), 2351,
;
2856, 2929, 3390 cmꢃ1 1H NMR (300 MHz, CDCl3, 25 ꢁC)
1
1759 (C=O), 2855, 2932, 3017, 3478 cmꢃ1; H NMR (300 MHz,
CDCl3, 25 ꢁC) ꢂ 1.60–1.75 (m, 4H), 2.42–2.59 (m, 4H), 3.03
(ddd, J ¼ 6:3, 6.3, 11.1 Hz, 1H), 4.10 (d, J ¼ 11:1 Hz, 1H), 5.24
(dd, J ¼ 6:3, 9.3 Hz, 1H), 5.47 (dd, J ¼ 6:3, 9.3 Hz, 1H), 6.20
(ddd, J ¼ 2:4, 3.6, 9.3 Hz, 1H), 6.30 (ddd, J ¼ 2:4, 3.6, 9.3 Hz,
1H), 6.63–6.75 (m, 2H), 7.02 (d, J ¼ 7:8 Hz, 2H), 7.11 (s, 1H),
7.19 (t, J ¼ 7:8 Hz, 1H), 7.33 (dd, J ¼ 7:8, 7.8 Hz, 2H); 13C NMR
(75 MHz, CDCl3, 25 ꢁC) ꢂ 20.1, 20.3, 23.0, 23.1, 39.3, 45.1,
119.9, 121.4, 121.5, 122.2, 123.1, 123.8, 125.7, 125.7, 125.8,
129.2, 130.8, 136.8, 142.7, 150.7, 169.2. Anal. Calcd for
C23H22O3: C, 79.74; H, 6.40%. Found: C, 79.48; H, 6.61%.
2-Furfuryl-2,5-dihydrofuran 5e. A colorless oil (44.0 mg,
0.14 mmol, 68% yield, dr = 67/33); IR (neat) 501, 608, 690,
751, 818, 900, 1022, 1074, 1141, 1162, 1193, 1254, 1441, 1492,
ꢂ 1.18 (d, J ¼ 6:0 Hz, 3H), 1.22 (d, J ¼ 6:0 Hz, 3H), 1.66–1.69
(m, 4H), 2.44–2.61 (m, 4H), 3.65 (sep, J ¼ 6:0 Hz, 1H), 3.76
(s, 3H), 5.02 (s, 1H), 7.10 (s, 1H); 13C NMR (100 MHz, CDCl3,
25 ꢁC) ꢂ 20.0, 20.1, 21.9, 21.9, 22.9, 22.9, 52.3, 70.6, 70.9,
120.9, 122.3, 137.3, 142.8, 170.0. HRMS (FAB) Calcd for
C14H21O4 (M þ Hþ): 253.1440. Found: 253.1442.
Furfuryl p-Nitrophenyl Ether 10d. A yellow oil (29.1 mg,
0.087 mmol, 44% yield); IR (neat) 640, 688, 733, 751, 763, 845,
877, 912, 969, 1039, 1112, 1202, 1243, 1299, 1340, 1384, 1436,
1516, 1592, 1760 (C=O), 2857, 2932 cmꢃ1; H NMR (300 MHz,
1
CDCl3, 25 ꢁC) ꢂ 1.62–1.70 (m, 4H), 2.48–2.58 (m, 4H), 3.82
(s, 3H), 5.74 (s, 1H), 7.00 (d, J ¼ 9:3 Hz, 2H), 7.18 (s, 1H),
8.19 (d, J ¼ 9:3 Hz, 2H); 13C NMR (75 MHz, CDCl3, 25 ꢁC)
ꢂ 19.9, 20.0, 22.6, 22.6, 53.0, 71.6, 115.3, 122.9, 122.9, 125.8,
138.3, 139.8, 142.3, 161.8, 167.3. Anal. Calcd for C17H17NO6:
C, 61.63; H, 5.17; N, 4.23%. Found: C, 61.71; H, 5.20; N, 3.94%.
1592, 1758 (C=O), 2855, 2932, 3081, 3478 cmꢃ1 1H NMR
;
(400 MHz, CD2Cl2, 25 ꢁC): major isomer, ꢂ 1.69–1.71 (m, 4H),
2.53–2.55 (m, 4H), 4.01 (d, J ¼ 7:2 Hz, 1H), 4.61 (d, J ¼
4:4 Hz, 2H), 5.44–5.48 (m, 1H), 5.99–6.01 (m, 2H), 7.03 (d, J ¼
7:6 Hz, 2H), 7.15 (s, 1H), 7.23 (dd, J ¼ 7:6, 7.6 Hz, 1H), 7.37 (dd,
J ¼ 7:6, 7.6 Hz, 2H); minor isomer, ꢂ 1.69–1.71 (m, 4H), 2.54–
2.56 (m, 4H), 3.96 (d, J ¼ 8:7 Hz, 1H), 4.65–4.69 (m, 2H),
5.52–5.58 (m, 1H), 5.68–5.72 (m, 1H), 5.94–5.96 (m, 1H), 7.06
(d, J ¼ 7:6 Hz, 2H), 7.15 (s, 1H), 7.23 (t, J ¼ 7:6 Hz, 1H), 7.37
(dd, J ¼ 7:6, 7.6 Hz, 2H); 13C NMR (100 MHz, CD2Cl2, 25 ꢁC):
major isomer, ꢂ 20.5, 20.7, 23.5, 23.6, 50.1, 75.8, 85.6, 120.1,
121.7, 122.8, 126.2, 127.7, 128.9, 129.6, 136.8, 142.3, 150.9,
168.5; minor isomer, ꢂ 20.4, 23.5, 23.5, 51.3, 75.9, 85.6, 120.1,
121.9, 122.9, 126.2, 127.8, 128.8, 129.7, 137.2, 141.8, 151.2,
168.8. Anal. Calcd for C20H20O4 (a mixture of isomers): C,
74.06; H, 6.21%. Found: C, 73.80; H, 6.19%.
ꢀ-Amino Acid Ester 11d.
A colorless oil (45.1 mg,
0.13 mmol, 69% yield); IR (neat) 691, 750, 920, 949, 997, 1033,
1111, 1196, 1307, 1366, 1435, 1504, 1598, 1751 (C=O), 2854,
;
2931, 3025 cmꢃ1 1H NMR (300 MHz, CDCl3, 25 ꢁC) ꢂ 1.60–
1.78 (m, 4H), 2.21–2.35 (m, 1H), 2.40–2.53 (m, 3H), 2.84 (s,
3H), 3.75 (s, 3H), 5.54 (s, 1H), 6.76 (d, J ¼ 7:5 Hz, 2H), 6.79
(t, J ¼ 7:5 Hz, 1H), 7.13 (s, 1H), 7.24 (dd, J ¼ 7:5, 7.5 Hz, 2H);
13C NMR (75 MHz, CDCl3, 25 ꢁC) ꢂ 20.1, 20.1, 22.9, 22.9,
34.2, 52.3, 59.3, 113.3, 117.9, 120.9, 122.4, 129.2, 137.0, 142.1,
149.3, 170.7. Anal. Calcd for C18H21NO3: C, 72.22; H, 7.07; N,
4.68%. Found: C, 72.39; H, 7.34; N, 4.61%.
ꢀ-Amino Acid Ester 12d.
A colorless oil (32.8 mg,
Furfuryl Methyl Ether 6d.
A colorless oil (36.6 mg,
0.090 mmol, 45% yield); IR (neat) 601, 701, 745, 908, 921, 988,
1039, 1073, 1095, 1271, 1359, 1447, 1494, 1590, 1754 (C=O),
0.16 mmol, 82% yield); IR (neat) 602, 763, 850, 920, 947, 1009,
1109, 1194, 1270, 1335, 1439, 1581, 1758 (C=O), 2856, 2932,
2855, 2933, 3059 cmꢃ1
;
1H NMR (300 MHz, CDCl3, 25 ꢁC)
3437 cmꢃ1
;
1H NMR (400 MHz, CDCl3, 25 ꢁC) ꢂ 1.68–1.70 (m,
ꢂ 1.37–1.53 (m, 4H), 1.90–1.98 (m, 1H), 2.05–2.17 (m, 1H),
2.35–2.41 (m, 2H), 3.80 (s, 3H), 5.73 (s, 1H), 6.83 (d, J ¼
7:5 Hz, 4H), 6.95 (dd, J ¼ 7:5, 7.5 Hz, 2H), 6.97 (s, 1H), 7.18
(dd, J ¼ 7:5, 7.5 Hz, 4H); 13C NMR (75 MHz, CDCl3, 25 ꢁC)
ꢂ 19.9, 19.9, 22.7, 22.7, 52.5, 59.4, 122.0, 122.2, 122.2, 122.2,
128.8, 136.8, 140.8, 146.0, 170.6. Anal. Calcd for C23H23NO3:
C, 76.43; H, 6.41; N, 3.88%. Found: C, 76.34; H, 6.45; N, 3.77%.
4H), 2.52–2.55 (m, 4H), 3.37 (s, 3H), 3.79 (s, 3H), 4.84 (s, 1H),
7.12 (s, 1H); 13C NMR (100 MHz, CDCl3, 25 ꢁC) ꢂ 20.1, 20.1,
23.0, 23.0, 52.5, 57.0, 74.5, 121.8, 122.3, 137.6, 141.8, 169.1.
Anal. Calcd for C12H16O4: C, 64.27; H, 7.19%. Found: C,
63.99; H, 7.23%.
Ethyl Furfuryl Ether 7d.
A colorless oil (30.1 mg,
0.12 mmol, 63% yield); IR (neat) 613, 727, 760, 935, 987, 1024,
1052, 1113, 1203, 1236, 1269, 1332, 1436, 1651, 1751 (C=O),
ꢀ-Amino Acid Ester 13d.
A colorless oil (26.4 mg,
0.091 mmol, 46% yield); IR (neat) 408, 507, 551, 602, 692, 749,
818, 849, 920, 988, 1074, 1147, 1176, 1202, 1256, 1311, 1385,
1434, 1504, 1603, 1738 (C=O), 2854, 2934, 3022, 3051,
2862, 2938, 3467 cmꢃ1
;
1H NMR (400 MHz, CDCl3, 25 ꢁC)
ꢂ 1.25 (t, J ¼ 7:2 Hz, 3H), 1.67–1.71 (m, 4H), 2.46–2.60 (m,
4H), 3.51 (q, J ¼ 7:2 Hz, 1H), 3.54 (q, J ¼ 7:2 Hz, 1H), 3.77 (s,
3H), 4.94 (s, 1H), 7.11 (s, 1H); 13C NMR (100 MHz, CDCl3,
3405 cmꢃ1
;
1H NMR (270 MHz, CDCl3, 25 ꢁC) ꢂ 1.66–1.80 (m,
4H), 2.48–2.53 (m, 4H), 3.75 (s, 3H), 4.76 (d, J ¼ 7:3 Hz, 1H),

K. Miki et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 9 (2008) 1163
5.13 (d, J ¼ 7:3 Hz, 1H), 6.61 (d, J ¼ 7:3 Hz, 2H), 6.73 (t, J ¼
7:3 Hz, 1H), 7.09 (s, 1H), 7.15 (dd, J ¼ 7:3, 7.3 Hz, 2H);
13C NMR (67.5 MHz, CDCl3, 25 ꢁC) ꢂ 20.1, 20.2, 22.9, 23.8,
52.8, 54.0, 113.3, 118.4, 119.4, 122.4, 129.1, 136.8, 142.4,
145.8, 170.5. Anal. Calcd for C17H19NO3: C, 71.56; H, 6.71; N,
4.91%. Found: C, 71.31; H, 6.83; N, 5.18%.
(d, J ¼ 7:6 Hz, 2H), 6.86 (t, J ¼ 7:6 Hz, 1H), 7.10 (s, 1H), 7.26
(dd, J ¼ 7:6, 7.6 Hz, 2H); 13C NMR (100 MHz, CDCl3, 25 ꢁC)
ꢂ 20.1, 20.4, 22.9, 23.0, 43.1, 58.2, 65.8, 112.9, 119.2, 120.3,
122.7, 129.4, 137.2, 142.0, 147.1, 166.6. HRMS (FAB) Calcd
for C18H20NO3 (M + Hþ): 298.1443. Found: 298.1443.
Triethyl(furfuryl)silane 19d.
A colorless oil (41.1 mg,
ꢀ-Amino Acid Ester 14d.
A colorless oil (7.8 mg,
0.13 mmol, 67% yield); IR (neat) 732, 772, 806, 836, 944, 972,
1007, 1072, 1163, 1240, 1435, 1650, 1712 (C=O), 1769, 2877,
0.024 mmol, 12% yield); IR (neat) 401, 606, 671, 692, 732, 803,
892, 919, 1044, 1093, 1203, 1351, 1442, 1481, 1526, 1583,
1739 (C=O), 2874, 2931, 3092, 3377 cmꢃ1; H NMR (400 MHz,
2951, 3450 cmꢃ1 1H NMR (300 MHz, CDCl3, 25 ꢁC) ꢂ 0.64
;
1
(q, J ¼ 7:8 Hz, 6H), 0.92 (t, J ¼ 7:8 Hz, 9H), 1.58–1.65 (m,
4H), 2.32–2.40 (m, 2H), 2.49–2.52 (m, 2H), 3.47 (s, 1H), 3.65
(s, 3H), 7.08 (s, 1H); 13C NMR (67.5 MHz, CDCl3, 25 ꢁC) ꢂ 3.3,
6.9, 20.2, 20.5, 23.2, 23.3, 33.8, 51.5, 116.7, 121.9, 135.6,
143.8, 172.2. Anal. Calcd for C17H28O3Si: C, 66.19; H, 9.15%.
Found: C, 65.98; H, 8.94%.
CDCl3, 25 ꢁC) ꢂ 1.55–1.67 (m, 4H), 2.49–2.52 (m, 4H), 3.73 (s,
3H), 3.74 (s, 3H), 4.50 (d, J ¼ 5:6 Hz, 1H), 5.06 (d, J ¼ 5:6 Hz,
1H), 6.59 (d, J ¼ 8:8 Hz, 2H), 6.75 (d, J ¼ 8:8 Hz, 2H), 7.09 (s,
1H); 13C NMR (100 MHz, CDCl3, 25 ꢁC) ꢂ 20.1, 20.2, 22.9,
23.0, 52.7, 55.0, 55.6, 114.7, 115.0, 119.4, 122.4, 136.8, 140.0,
142.6, 152.7, 170.7. HRMS (FAB) Calcd for C18H21NO4 (Mþ):
315.1471. Found: 315.1472.
Furfuryltriphenylsilane 20d.
A white solid (17.8 mg,
0.039 mmol, 20% yield); mp 111.2–111.6 ꢁC; IR (KBr) 479, 503,
699, 740, 847, 986, 1114, 1175, 1189, 1276, 1308, 1335, 1428,
ꢀ-Amino Acid Ester 15d.
A yellow solid (41.2 mg,
0.12 mmol, 62% yield); mp 131.2–131.8 ꢁC; IR (KBr) 497, 696,
754, 763, 842, 1004, 1115, 1149, 1185, 1218, 1252, 1292, 1317,
1731 (C=O), 2848, 2917, 2937, 3071, 3427 cmꢃ1 1H NMR
;
(400 MHz, CDCl3, 25 ꢁC) ꢂ 1.46–1.62 (m, 4H), 2.05–2.12 (m, 1H),
2.21–2.27 (m, 1H), 2.39–2.41 (m, 2H), 3.38 (s, 3H), 4.28 (s, 1H),
6.91 (s, 1H), 7.32 (dd, J ¼ 7:2, 7.2 Hz, 6H), 7.39 (t, J ¼ 7:2 Hz,
3H), 7.49 (d, J ¼ 7:2 Hz, 6H); 13C NMR (100 MHz, CDCl3, 25 ꢁC)
ꢂ 20.2, 20.5, 23.1, 23.2, 36.4, 51.6, 118.2, 121.9, 127.5, 129.6,
132.7, 135.8, 136.0, 142.1, 171.3. Anal. Calcd for C29H28O3Si:
C, 76.95; H, 6.24%. Found: C, 76.53; H, 6.33%. HRMS (FAB)
Calcd for C29H28O3Si (Mþ): 452.1808. Found: 452.1808.
1474, 1500, 1523, 1597, 1728 (C=O), 2855, 2935, 3385 cmꢃ1
;
1H NMR (400 MHz, CDCl3, 25 ꢁC) ꢂ 1.58–1.69 (m, 4H), 2.39–
2.51 (m, 4H), 3.80 (s, 3H), 5.18 (d, J ¼ 6:4 Hz, 1H), 5.59 (d,
J ¼ 6:4 Hz, 1H), 6.55 (d, J ¼ 9:2 Hz, 2H), 7.10 (s, 1H), 8.07 (d,
J ¼ 9:2 Hz, 2H); 13C NMR (100 MHz, CDCl3, 25 ꢁC) ꢂ 20.0,
20.1, 22.8, 22.8, 53.1, 53.3, 111.7, 120.2, 122.7, 126.1, 137.3,
138.9, 140.9, 150.7, 169.3. Anal. Calcd for C17H18N2O5: C,
61.81; H, 5.49; N, 8.48%. Found: C, 61.66; H, 5.53; N, 8.29%.
n-Butyl Furfuryl Sulfide 21d.
A colorless oil (19.5 mg,
Furfurylsulfonamide 16d.
A
colorless oil (37.1 mg,
0.069 mmol, 35% yield); IR (neat) 480, 535, 606, 671, 692, 732,
803, 845, 892, 919, 1045, 1093, 1166, 1202, 1351, 1440, 1481,
1529, 1538, 1620, 1693, 1735 (C=O), 1972, 2436, 2872, 2931,
;
3091, 3383 cmꢃ1 1H NMR (270 MHz, CD2Cl2, 25 ꢁC) ꢂ 0.80
0.10 mmol, 51% yield); IR (neat) 402, 558, 671, 704, 736, 815,
1010, 1034, 1090, 1162, 1269, 1288, 1337, 1384, 1438, 1598,
1721, 1746 (C=O), 2857, 2934, 3279 cmꢃ1; H NMR (400 MHz,
1
CDCl3, 25 ꢁC) ꢂ 1.56–1.59 (m, 4H), 2.34–2.37 (m, 7H), 3.64 (s,
3H), 5.11 (d, J ¼ 7:6 Hz, 1H), 5.63 (d, J ¼ 7:6 Hz, 1H), 6.88 (s,
1H), 7.18 (d, J ¼ 8:0 Hz, 2H), 7.58 (d, J ¼ 8:0 Hz, 2H); 13C NMR
(100 MHz, CDCl3, 25 ꢁC) ꢂ 19.7, 19.9, 21.5, 22.7, 22.8, 52.0,
53.1, 120.7, 122.1, 126.8, 129.1, 136.9, 137.0, 140.3, 143.0,
168.3. Anal. Calcd for C18H21NO5S: C, 59.49; H, 5.82; N,
3.85%. Found: C, 59.34; H, 5.79; N, 3.67%.
(t, J ¼ 7:3 Hz, 3H), 1.29 (tq, J ¼ 7:3, 7.3 Hz, 2H), 1.42 (tq, J ¼
7:3, 7.3 Hz, 2H), 1.58–1.60 (m, 4H), 2.41–2.46 (m, 7H), 3.63 (s,
3H), 4.59 (s, 1H), 7.02 (s, 1H); 13C NMR (67.5 MHz, CD2Cl2,
25 ꢁC) ꢂ 20.4, 20.7, 22.3, 23.4, 23.4, 31.6, 31.7, 32.1, 44.8,
53.0, 120.3, 122.9, 137.1, 142.0, 169.4. HRMS (FAB) Calcd for
C15H22O3S (Mþ): 282.1290. Found: 282.1296.
Furfuryl Phenyl Sulfide 22d.
A colorless oil (35.6 mg,
ꢀ-Amino Acid Ester 17d.
A colorless oil (59.8 mg,
0.12 mmol, 59% yield); IR (neat) 404, 692, 738, 798, 900, 947,
977, 1008, 1047, 1143, 1163, 1268, 1295, 1384, 1435, 1640,
0.18 mmol, 90% yield); IR (neat) 693, 749, 1007, 1038, 1095,
1110, 1165, 1204, 1276, 1383, 1436, 1504, 1598, 1738 (C=O),
1
1692, 1708 (C=O), 2859, 2943, 3412 cmꢃ1; H NMR (300 MHz,
2856, 2932, 3437 cmꢃ1
;
1H NMR (300 MHz, CDCl3, 25 ꢁC)
C4D8O, 25 ꢁC) ꢂ 1.54–1.57 (m, 4H), 2.33–2.47 (m, 4H), 3.63
(s, 3H), 5.04 (s, 1H), 7.09 (s, 1H), 7.22–7.33 (m, 5H); 13C NMR
(75 MHz, C4D8O, 25 ꢁC) ꢂ 20.9, 20.9, 23.9, 23.9, 50.3, 52.6,
121.4, 123.1, 128.7, 129.3, 129.5, 134.5, 137.8, 142.5, 168.7.
HRMS (FAB) Calcd for C17H19O3S (M þ Hþ): 303.1055. Found:
303.1048.
ꢂ 1.56–1.78 (m, 4H), 2.15–2.30 (m, 1H), 2.41–2.60 (m, 3H),
3.08 (br s, 1H), 3.24 (ddd, J ¼ 3:4, 3.9, 15.1 Hz, 1H, N–CH2),
3.48 (ddd, J ¼ 3:9, 4.9, 11.2 Hz, 1H, O–CH2), 3.56 (ddd,
J ¼ 3:9, 4.9, 15.1 Hz, 1H, N–CH2), 3.67 (ddd, J ¼ 3:4, 3.9,
11.2 Hz, 1H, O–CH2), 3.82 (s, 3H), 5.46 (s, 1H), 6.80 (d,
J ¼ 7:8 Hz, 2H), 6.83 (t, J ¼ 7:8 Hz, 1H), 7.15 (s, 1H), 7.25
(dd, J ¼ 7:8, 7.8 Hz, 2H) (The peaks between 3.24–3.67 ppm were
assigned by using D2O experiments, see the Supporting Informa-
tion); 13C NMR (75.5 MHz, CDCl3, 25 ꢁC) ꢂ 20.0, 20.1, 22.8,
22.9, 49.1, 52.9, 59.8, 60.3, 114.7, 118.9, 121.7, 122.6, 129.3,
137.4, 141.3, 147.7, 172.3. HRMS (FAB) Calcd for C19H24NO4
(M þ Hþ): 330.1705. Found: 330.1710.
Furfuryl p-Methoxyphenyl Sulfide 23d.
A colorless oil
(48.7 mg, 0.14 mmol, 73% yield); IR (neat) 418, 527, 606, 639,
671, 692, 732, 803, 831, 892, 919, 1044, 1093, 1149, 1173,
1288, 1351, 1441, 1481, 1493, 1525, 1569, 1620, 1692, 1732
(C=O), 2868, 2933, 3091, 3352 cmꢃ1
;
1H NMR (270 MHz,
CD2Cl2, 25 ꢁC) ꢂ 1.54–1.68 (m, 4H), 1.83–1.95 (m, 1H), 2.24–
2.32 (m, 1H), 2.45–2.48 (m, 2H), 3.69 (s, 3H), 3.78 (s, 3H),
4.82 (s, 1H), 6.80 (d, J ¼ 8:9 Hz, 2H), 7.11 (s, 1H), 7.24 (d,
J ¼ 8:9 Hz, 2H); 13C NMR (65 MHz, CD2Cl2, 25 ꢁC) ꢂ 20.3,
20.4, 23.3, 23.3, 50.5, 55.6, 114.5, 121.5, 122.8, 123.2, 137.2,
137.3, 141.3, 160.7, 168.7. HRMS (FAB) Calcd for C18H20O4S
(Mþ): 332.1082. Found: 332.1801.
N-Phenylmorpholin-2-one 18d.
0.033 mmol, 17% yield); IR (neat) 692, 733, 910, 1075, 1204,
1278, 1378, 1468, 1504, 1600, 1753 (C=O), 2854, 2931 cmꢃ1
1H NMR (400 MHz, CDCl3, 25 ꢁC) ꢂ 1.60–1.75 (m, 4H), 2.39–
2.65 (m, 4H), 3.61 (ddd, J ¼ 3:6, 10.0, 11.6 Hz, 1H), 3.68 (ddd,
J ¼ 3:2, 3.6, 11.6 Hz, 1H), 4.56 (ddd, J ¼ 3:2, 3.6, 11.6 Hz,
1H), 4.85 (ddd, J ¼ 3:6, 10.0, 11.6 Hz, 1H), 5.42 (s, 1H), 6.70
A colorless oil (9.8 mg,
;
Furfuryl p-Nitrophenyl Sulfide 24d. A yellow oil (55.5 mg,
0.16 mmol, 80% yield); IR (neat) 411, 473, 539, 622, 638, 723,

1164 Bull. Chem. Soc. Jpn. Vol. 81, No. 9 (2008)
Catalytic Insertion Reactions of Carbenoids
740, 761, 801, 825, 853, 902, 948, 985, 1009, 1047, 1110, 1143,
1218, 1296, 1347, 1397, 1433, 1477, 1579, 1595, 1633, 1644,
T. Ye, Modern Catalytic Methods for Organic Synthesis with
Diazo Compounds, Wiley-Interscience, New York, 1998.
1
1681, 1743 (C=O), 2856, 2927, 3097 cmꢃ1; H NMR (300 MHz,
2
For reviews on addition reactions of ꢀ-bonds, see: a) T.
CD2Cl2, 25 ꢁC) ꢂ 1.61–1.67 (m, 4H), 2.46–2.49 (m, 4H), 3.68
(s, 3H), 5.49 (s, 1H), 7.13 (s, 1H), 7.40 (d, J ¼ 9:0 Hz, 2H),
8.06 (d, J ¼ 9:0 Hz, 2H); 13C NMR (75 MHz, CD2Cl2, 25 ꢁC) ꢂ
19.9, 20.3, 23.0, 23.0, 49.7, 52.2, 120.8, 122.5, 123.4, 124.1,
133.6, 137.4, 141.5, 145.7, 168.4. HRMS (FAB) Calcd for
C17H17NO5S (Mþ): 347.0827. Found: 347.0827.
Ye, M. A. McKervey, Chem. Rev. 1994, 94, 1091. b) M. P. Doyle,
D. C. Forbes, Chem. Rev. 1998, 98, 911. c) H. M. L. Davies,
R. E. J. Beckwith, Chem. Rev. 2003, 103, 2861. d) D. J. Miller,
C. J. Moody, Tetrahedron 1995, 51, 10811. e) M. P. Doyle,
J. Org. Chem. 2006, 71, 9253. f) H. M. L. Davies, J. Nikolai,
Org. Biomol. Chem. 2005, 3, 4176. g) H. M. L. Davies, Angew.
Chem., Int. Ed. 2006, 45, 6422. h) S. Matsubara, K. Oshima, K.
Utimoto, J. Organomet. Chem. 2001, 617–618, 39.
Cr-Catalyzed Addition Reaction of 1b with MeOH. A solu-
tion of [Cr(CO)6] (66 mg, 0.30 mmol) and THF (24 mL, 0.30
mmol) in benzene (10 mL) in flame-dried Schlenk tube under
N2 was irradiated by Hg lamp (450 W, 350 nm) at room tempera-
ture for 2 h. After N2 blowing bubbles into the yellow solution, to
the yellow solution were added 1b (60 mg, 0.25 mmol) and MeOH
(20 mL, 0.50 mmol) at room temperature. The color of the reaction
mixture gradually changed from deep blue to yellowish brown as
the reaction proceeded. The solvent was removed under reduced
pressure and the residue was subjected to column chromatography
on SiO2 with hexane/AcOEt as an eluent to afford a white
solid 25b (48 mg, 69% yield); mp 68.3–69.8 ꢁC; IR (KBr) 706,
937, 965, 1069, 1081, 1207, 1391, 1573, 1591, 1651 (C=O),
3
For selected addition reactions of C–H, see: a) M. P.
Doyle, W. R. Winchester, J. A. A. Hoorn, V. Lynch, S. H.
Simonsen, R. Ghosh, J. Am. Chem. Soc. 1993, 115, 9968. b)
D. F. Taber, R. Ealter, R. P. Meagley, J. Org. Chem. 1994, 59,
6014. c) H. M. L. Davies, T. Hansen, M. R. Churchill, J. Am.
Chem. Soc. 2000, 122, 3063. d) H. M. L. Davies, E. G.
Antoulinakis, Org. Lett. 2000, 2, 4153. e) H. M. L. Davies,
M. V. A. Grazini, E. Aouad, Org. Lett. 2001, 3, 1475. f) M. M.
Diaz-Requejo, T. R. Belderrain, M. C. Nicasio, S. Trofimenko,
P. J. Perez, J. Am. Chem. Soc. 2002, 124, 896. g) K. Minami,
H. Saito, H. Tsutsui, H. Nambu, M. Anada, S. Hashimoto, Adv.
Synth. Catal. 2005, 347, 1483. h) R. P. Reddy, G. H. Lee,
H. M. L. Davies, Org. Lett. 2006, 8, 3437. i) H. M. L. Davies,
S. J. Hedley, B. R. Bohall, J. Org. Chem. 2005, 70, 10737. j)
S. J. Hedley, D. L. Ventura, P. M. Dominiak, C. L. Nygren,
H. M. L. Davies, J. Org. Chem. 2006, 71, 5349. k) N. R. Candeias,
P. M. P. Gois, C. A. M. Afonso, J. Org. Chem. 2006, 71, 5489.
l) A. Ni, J. E. France, H. M. L. Davies, J. Org. Chem. 2006, 71,
5594. m) J. L. Thompson, H. M. L. Davies, J. Am. Chem. Soc.
2933 cmꢃ1 1H NMR (CDCl3) ꢂ 1.60–1.79 (m, 4H), 2.20–2.28
;
(m, 2H), 2.47–2.62 (m, 1H), 2.62–2.78 (m, 1H), 3.47 (s, 3H),
5.74 (s, 1H), 6.46 (s, 1H), 7.39–7.54 (m, 3H), 7.92–7.96 (m,
2H); 13C NMR (CDCl3) ꢂ 21.2, 22.3, 22.8, 24.0, 54.8, 97.4,
107.8, 128.0, 128.2, 131.9, 134.2, 139.3, 149.2, 170.6, 189.2.
HRMS (FAB) Calcd for C17H19O3 (M þ Hþ): 271.1334. Found:
271.1327. 25b was gradually isomerized under slightly acidic con-
ditions (e.g. in CDCl3 at room temperature) to afford the thermo-
dynamically more stable diastereoisomer 25b0 quantitatively:
A white solid; mp 82.7–83.4 ꢁC; IR (KBr) 629, 705, 715, 772,
854, 935, 1004, 1218, 1317, 1569, 1600, 1650 (C=O), 2860,
´
2007, 129, 6090. n) J. M. Fraile, J. I. Garcıa, J. A. Mayoral, M.
Roldan, Org. Lett. 2007, 9, 731. o) H. M. Mbuvi, L. K. Woo,
´
Organometallics 2008, 27, 637.
For selected addition reactions of O–H, see: a) W. Kirmse,
2930 cmꢃ1
;
1H NMR (CDCl3) ꢂ 1.63–1.78 (m, 4H), 2.20–2.25
4
(m, 4H), 3.55 (s, 3H), 5.92 (s, 1H), 5.94 (s, 1H), 7.39–7.52 (m,
3H), 7.92 (d, J ¼ 7:0 Hz, 2H); 13C NMR (CDCl3): ꢂ 20.3, 21.7,
21.7, 22.1, 56.0, 92.0, 111.1, 127.7, 128.1, 131.5, 134.6, 139.8,
146.8, 168.4, 188.9.
Crystallographic data have been deposited with Cambridge
Crystallographic Data Centre. Deposition numbers CCDC-
687434 for compound 25b and CCDC-687435 for compound
25b0. Copies of the data can be obtained free of charge via
http://www.ccdc.cam.ac.uk/conts/retrieving.html (or from the
Cambridge Crystallographic Data Centre, 12, Union Road, Cam-
bridge, CB2 1EZ, UK; Fax: +44 1223 336033; e-mail: deposit@
ccdc.cam.ac.uk).
in Advances in Carbene Chemistry, ed. by U. Brinker, JAI Press,
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This work was financially supported by the Ministry of
Education, Culture, Sports, Science and Technology of Japan
and by Tokuyama Science Foundation.
Supporting Information
1H and 13C NMR spectra of 1e, 2b–2d, 9d, 14d, 17c, 18c, 20d,
21d, 22d, and 23d, and also X-ray crystallographic data of 25b
and 25b0 (CCDC #687434 (25b) and #687435 (25b0), respec-
tively). This material is available free of charge on the Web at:
http://www.csj.jp/journals/bcsj/.
5
For selected addition reactons of N–H, see: a) C. J. Moody,
E. Swann, Synlett 1998, 135. b) C. J. Moody, E. Swann, L. Ferris,
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H. Li, P. Livant, J. Org. Chem. 2001, 66, 6729. d) M. E.
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