Tandem sequential ring-closing metathesis/Diels-Alder/cross-metathesis: Formation of polycyclic compounds by a new three-component reaction

Article abstract of DOI:10.1002/ejoc.200600946

Polycyclic oxygenated compounds have been generated from penta- or hexadienyl propargyl ethers by a new procedure that combines the selective formation of a 1,3-diene by ring-closing metathesis (RCM), a Diels-Alder (DA) reaction and subsequent cross-metat

Full text of DOI:10.1002/ejoc.200600946

FULL PAPER
DOI: 10.1002/ejoc.200600946
Tandem Sequential Ring-Closing Metathesis/Diels–Alder/Cross-Metathesis:
Formation of Polycyclic Compounds by a New Three-Component Reaction
Marie-Alice Virolleaud[a] and Olivier Piva*[a]
Dedicated to Professor Dieter Enders on the occasion of his 60th birthday
Keywords: Ring-closing metathesis / Cycloaddition / Tandem reaction / Cross-metathesis / Enynes
Polycyclic oxygenated compounds have been generated
from penta- or hexadienyl propargyl ethers by a new pro-
cedure that combines the selective formation of a 1,3-diene
by ring-closing metathesis (RCM), a Diels–Alder (DA) reac-
tion and subsequent cross-metathesis (CM) with a chosen al-
kene, which allows the functionalization of the vinyl group
generated during the first step. All these processes can be
performed in a one-pot reaction with a yield of up to 63%.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2007)
development of tandem or domino procedures.[9–12] For ex-
ample, enyne ring-closing metathesis provides a direct entry
to cyclic 1,3-dienes which could be further used in Diels–
Alder reactions.[13–23] In some cases, the thermal cycload-
dition reaction has been performed directly without purifi-
cation to avoid the isolation of sensitive or volatile dienes
generated during the first step. In this way, complex polycy-
clic structures can be obtained in one-pot procedures. In
connection with our interest in metathesis reactions, we re-
cently reported the access to functionalized γ- and δ-lac-
tones through a tandem reaction starting from 1,4-pen-
Introduction
Since the commercial availability of air-stable catalysts
such as 1a and 1b that tolerate numerous functionalities,
alkene metathesis has been widely used for the formation
of complex structures and therefore used in the total syn-
thesis of natural products.[1–6] Reactions of the same ruthe-
nium carbene complexes and other metal catalysts with en-
ynes have also attracted the attention of chemists and usu-
ally deliver 1,3-dienes in high yields.[7,8] The usual mild con-
ditions required for these reactions have also favoured the
Scheme 1. Tandem RCM/CM of pentadienyl esters.
tadien-3-yl acrylates or 3-butenoates.[24,25] After an initial
[a] Université LYON 1; UMR CNRS 5246 – ICBMS – Equipe RCM reaction, subsequent cross-coupling with an alkene
chimie organique – Photochimie et synthèse,
already present in the reaction medium afforded the target
molecules in high yield and with (E) stereocontrol of the
double bond fixed on the lateral chain (Scheme 1). Despite
Bat. Raulin/4, 43 Bd du 11 Novembre 1918, 69622 Villeur-
banne, France
Fax: +33-4-7244-8136
E-mail: piva@univ-lyon1.fr
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Polycyclic Compounds by a New Three-Component Reaction
FULL PAPER
Scheme 2. Sequential ring-closing metathesis, Diels–Alder and cross-metathesis reaction of propargyl ethers 2 and 3.
their apparent simplicity and great synthetic potential, it 1,4-pentadien-3-ol with propargyl bromide in moderate-to-
should be mentioned that to date, only a few processes com- acceptable yields (Scheme 3).[39,40] Attempts to improve the
bining both RCM and CM have been successfully designed yields of 3 by using the corresponding propargyl triflate or
for alkenes[26–30] or enynes.[31–38]
by varying the nature of the solvent or base were unsuccess-
In order to develop new tandem procedures for the syn- ful.
thesis of oxygenated heterocycles that also combine RCM
and CM reactions, we have now investigated the reactivity
of unsaturated propargyl ethers 2 and 3 (n, m = 0, 1) in the
presence of catalytic amounts of Grubbs reagents 1a or 1b
(Scheme 2). In our strategy, RCM was expected to deliver
first a cyclic 1,3-diene that could be immediately subjected
to a Diels–Alder cycloaddition reaction. To avoid intermo-
Scheme 3. Formation of propargyl ethers 2 and 3 from the corre-
lecular cross-coupling between the alkynyl group and an-
other alkene moiety and the formation of acyclic 1,3-dienes,
we reasoned that the ring-closing metathesis reaction
should be carried out first and under highly dilute condi-
tions. Finally, the vinyl group generated during the first cyc-
lization step could later be functionalized by cross-metathe-
sis. For all these processes, it is important to note that the
catalyst should tolerate various functionalities such as
ketones and carboxylic acid derivatives (esters or amides)
often present in dienophiles. According to the overall
scheme, three different components could take part in the
planned procedure and could give rapid (ideally in a one-
pot procedure) access to highly functionalized polycyclic
structures.
sponding alcohols.
Ether 2 (Scheme 4) was treated with Grubbs type I cata-
lyst 1a (5%) in dichloromethane (10–2 ). After heating for
4 h, TLC control revealed the complete disappearance of
the starting material and the formation of a new compound
with a similar polarity which was later identified as the vi-
nyl-1,3-diene 4 possessing a six-membered ring. Note that
no trace of 5 was detected. Cookson’s reagent (4-phenyl-
4,5-dihydro-3H-1,2,4-triazole-3,5-dione, 6), which is widely
known to undergo Diels–Alder reactions even at room tem-
perature,[41–43] was then added to the reaction mixture. Af-
ter stirring for only 1 h, polar products were detected by
TLC control and were identified as compounds 7/7Ј which
could not be separated by flash chromatography.
The formation of a six-membered cycle was confirmed
by H NMR spectroscopy and was in agreement with re-
Results and Discussion
1
Starting materials 2 and 3 were respectively prepared by sults obtained by Lee with related alkynylsilyloxy-tethered
alkylation of commercially available 1,5-hexadien-3-ol and dienynes.[44] Similarly, 4 has also been used in a [4+2] cyclo-
Scheme 4. Sequential RCM/Diels–Alder reaction of ether 2.
Eur. J. Org. Chem. 2007, 1606–1612
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M.-A. Virolleaud, O. Piva
FULL PAPER
addition reaction with 8,[45] which required a higher tem-
perature and longer reaction time. After 24 h in refluxing
dichloromethane, a mixture of two diastereomers 9/9Ј was
isolated in 59% yield (Figure 1).
Scheme 6. Cross-metathesis of 7/7Ј with alkene 10.
Table 1. Results of the cross-metathesis reaction of 7/7Ј with alkene
10.
Figure 1. Product obtained in the reaction with diethyl azodicar-
boxylate (8) as dienophile.
Since the regioselectivity of the enyne RCM reaction was
high, we decided to functionalize the lateral vinyl group
through a cross-metathesis reaction. We considered that
RCM and CM could be performed advantageously by using
Grubbs type I catalyst 1a in the same vessel. Therefore,
ether 2 dissolved in dichloromethane was directly heated in
the presence of catalyst 1a and alkene 10c was introduced
in large excess in the middle of the reaction (5 equiv.). The
reaction was stirred for 4 h under reflux and dienophile 6
was subsequently added at room temperature (Scheme 5,
Method A). After purification of the reaction mixture by
flash chromatography, compounds 7/7’ were obtained as the
major products (62%) with two new compounds also iso-
lated after careful separation by flash chromatography
which were identified as the two epimeric compounds 11c/
11Јc. At this stage, the poor reactivity of 7/7Ј in the cross-
[a] Ratio of diastereoisomers determined for the crude product by
1H NMR spectroscopy. [b] Reaction performed in the presence of
Ti(OiPr)4 (0.3 equiv.).
This process was next generalized for alkenes 10b–d
metathesis reaction was attributed to the steric hindrance (Table 1). The CM reaction was performed using the condi-
of the vinyl group and the propensity of terminal alkene 10 tions defined above. Similar yields were obtained with ter-
to react in a competitive self-coupling process.
minal alkenes 10b,c, whereas the use of 1,4-dibromobut-2-
The reaction conditions were then reconsidered to im- ene led to 11d/11Јd less efficiently. NOE experiments were
prove the yield of the last process. The vinyl group of cy- performed on each diastereomer prepared from 10a–d in
cloadducts 7/7Ј was functionalized by using the ruthenium order to assign the syn or anti configuration of compounds
catalyst 1a or 1b in the presence of 2 equiv. of 1-tridecene 11/11Ј.
10a chosen as a model (Scheme 6, Table 1). The best results
In order to develop an efficient one-pot three-component
were clearly obtained with catalyst 1b which is widely reaction, we then selected the optimal conditions for each
known to react in the presence of a variety of functionalities process of the RCM/DA/CM sequence. As a consequence,
and does not suffer from steric hindrance with the sub- ether 2 was treated with catalyst 1a to deliver first a 1,3-
strates, as already pointed out in the literature.[1,4–5] diene. The cycloaddition reaction then took place following
1
Furthermore, the H NMR spectra allowed the (E) confor- the introduction of Cookson’s reagent 6. Alkene 10
mation to be assigned to the exocyclic double bond in both (2 equiv.) was finally added along with Grubbs type II cata-
cases (J = 15.6 Hz), reflecting the reversibility of the final lyst 1b to promote the cross-metathesis reaction (Scheme 7,
coupling reaction.
Method B).
Scheme 5. One-pot RCM/CM/Diels–Alder reaction of ether 2: Method A.
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Polycyclic Compounds by a New Three-Component Reaction
FULL PAPER
Conclusions
In conclusion, we have described a straightforward one-
pot synthesis of new tricyclic compounds by a process
based on regioselective ring-closing metathesis of an enyne
generating a 1,3-diene. This diene was subsequently in-
volved in a Diels–Alder reaction and the vinyl moiety was
functionalized by cross-metathesis to yield a product with
(E) stereochemistry. Work is now in progress to perform
this tandem procedure with other dienophiles and in this
way access more complex polycyclic structures.
Scheme 7. One-pot RCM/Diels–Alder/CM reaction of ether 2:
Method B.
Following this method, tricyclic compounds 11/11Ј were
synthesized in a one-pot procedure with high overall yields
(Table 2).
Experimental Section
Table 2. Results of the one-pot RCM/Diels–Alder/CM reaction of
ether 2 following Method B.
General Remarks: NMR spectra were recorded with a Bruker AC
300 or AM 500 spectrometer. H and 13C NMR were recorded in
1
CDCl3; chemical shifts are calibrated with reference to the residual
proton and carbon resonances of the solvent (CDCl3: δH = 7.26,
δC = 77.36 ppm). Data are reported as follows: chemical shift, mul-
tiplicity (s = singlet, d = doublet, t = triplet, q = quartet, quint =
quintuplet, m = multiplet), coupling constant (Hz), integration and
assignment. High-resolution mass spectra were recorded with a
Finnigan-MAT 95XL spectrometer. Tetrahydrofuran was distilled
from sodium and benzophenone, whereas HPLC grade dichloro-
methane was used. Grubbs type I and II catalysts are commercially
available compounds from Aldrich and were used as received. TLC
analysis was conducted using the spray reagent molybdic acid and
heating until development of colour.
A similar RCM/DA process was then applied to pen-
tadienyl ether 3 (Scheme 8). As for 2, the initial ring-closing
metathesis took place rapidly within only 4 h leading to the
1,3-diene 12 (TLC control). This compound was trapped
directly with 6 to deliver only one cycloadduct 13 in 47%
1,5-Hexadien-3-yl Propargyl Ether (2): Sodium hydride (60% in
mineral oil, 300 mg, 7.5 mmol) was added to a stirred suspension
of 1,5-hexadien-3-ol (0.49 mL, 4.3 mmol), propargyl bromide (80%
yield. In this case, the formation of a single diastereoisomer in toluene, 0.65 mL, 7.5 mmol) and tetrabutylammonium iodide
(185 mg, 0.5 mmol) in dry THF (10 mL). The reaction mixture was
stirred at room temperature for 12 h. The reaction was quenched
by addition of aqueous saturated solution of NH4Cl (7 mL). The
aqueous phase was extracted with Et2O (2ϫ15 mL) and the com-
bined organic layers were washed with brine (15 mL) and dried
with MgSO4. After filtration, the solvent was removed. The residue
was purified by flash column chromatography [petroleum ether
(PE)/ethyl acetate, 95:5] to afford 2 as a light yellow liquid. Yield
was observed probably because the vinyl group is closer to
the diene part than in precursor 4. At this stage, compound
13 was subjected to two new cross-coupling reactions per-
formed in the presence of only 5% catalyst 1b. The reac-
tions furnished functionalized products 14b,c with (E)
stereochemistry with the same efficiency.
A one-pot procedure following Method A and in the
presence of catalyst 1a has also been carried out with 5-
bromopentene 10e. In this way, new product 14e was ob-
tained directly from ether 3 with a modest yield of 32%.
1
63% (378 mg). Rf = 0.71 (PE/EtOAc, 95:5). H NMR (300 MHz,
CDCl3): δ = 2.39 (t, J = 2.3 Hz, 1 H, ϵCH), 2.24–2.47 (m, 2 H,
CH2), 3.97 (q, J = 6.5 Hz, 1 H, CHO), 4.04 (dd, J = 15.7, 2.3 Hz,
Scheme 8. Formation of 14 through a RCM/Diels–Alder reaction and subsequent cross-metathesis from 1,4-pentadien-3-yl ether 3 or by
a tandem process.
Eur. J. Org. Chem. 2007, 1606–1612
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M.-A. Virolleaud, O. Piva
1 H, CH2O), 4.21 (dd, J = 15.7, 2.3 Hz, 1 H, CH2O), 5.08–5.32 (C=O) ppm. HRMS: calcd. for C15H22N2O5+H+ = 310.1519;
FULL PAPER
(m, 4 H, =CH2), 5.66 (ddd, J = 17.7, 9.8, 7.9 Hz, 1 H,
found 310.1518.
CH2=CHCH2), 5.81 (ddd,
J = 17.1, 10.2, 7.0 Hz, 1 H,
Compound 13: Obtained from ether 3 and 6 as a brown oil. Yield
47% (116 mg). Rf = 0.38 (PE/EtOAc, 50:50). H NMR (300 MHz,
CH2=CHCHO) ppm. 13C NMR (75 MHz, CDCl3): δ = 40.0 (CH2),
55.4 (CH2O), 74.2 (ϵCH), 79.7 (CHO), 80.3 (Cq), 117.3–118.7
(=CH2), 134.4–137.5 (=CH) ppm.
1
CDCl3): δ = 3.97–4.19 (m, 2 H, CH2N), 4.43–4.64 (m, 4 H, CH2O,
CHO, CHN), 5.29 (dt, J = 10.4, 1.1 Hz, 1 H, =CH2cis), 5.51 (dt, J
= 17.3, 1.3 Hz, 1 H, =CH2trans), 5.83 (s, 1 H, CHCH2N), 6.42 (ddd,
J = 17.2, 10.6, 5.3 Hz, 1 H, CH2=CH), 7.30–7.58 (m, 5 H, H
arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = 42.9 (CH2N), 62.5
(CHN), 68.1 (CH2O), 81.9 (CHO), 113.2 (CHCH2N), 117.1
(=CH2), 125.7, 128.5, 129.4 (CH arom.), 131.1 (Cq arom.), 136.3
(CH2=CH), 136.9 (Cq-CH2O), 151.9, 153.9 (C=O) ppm. HRMS:
calcd. for C16H15N3O3+H+ = 298.1192; found 298.1191.
1,4-Pentadien-3-yl Propargyl Ether (3): Ether 3 was prepared as a
light-yellow liquid following the same procedure as above starting
from 1,4-pentadien-3-ol. Yield 27% (167 mg). Rf = 0.75 (PE/
EtOAc, 95:5). 1H NMR (300 MHz, CDCl3): δ = 2.41 (t, J = 2.4 Hz,
1 H, ϵCH), 4.15 (d, J = 2.4 Hz, 2 H, CH2O), 4.45 (tt, J = 6.6,
1.0 Hz, 1 H, CHO), 5.25 (dt, J = 10.2, 1.1 Hz, 2 H, =CH2cis), 5.31
(dt, J = 17.1, 1.2 Hz, 2 H, =CH2trans), 5.78 (ddd, J = 17.1, 10.2,
6.6 Hz, 2 H, =CH) ppm. 13C NMR (75 MHz, CDCl3): δ = 55.2
(CH2O), 74.5 (ϵCH), 80.0 (Cq), 80.6 (CHO), 118.0 (=CH2), 136.9
(=CH) ppm.
General Procedure for CM. Preparation of Compounds 11a/11Јa:
Catalyst 1b (17 mg, 5%) was added to a dichloromethane solution
(5 mL) of compounds 7/7Ј (130 mg, 0.42 mmol) and alkene 10a
(0.20 mL, 0.84 mmol).The reaction mixture was heated for 6 h at
40 °C. After cooling to room temperature, the solvent was removed
and the residue purified by flash column chromatography (petro-
leum ether/ethyl acetate, 80:20) to afford 11a and 11Јa in 81% yield
and with a 63:37 anti/syn ratio. anti-11a: Brown oil. Rf = 0.73 (PE/
EtOAc, 50:50). 1H NMR (300 MHz, CDCl3): δ = 0.88 (t, J =
6.5 Hz, 3 H, CH3), 1.12–1.47 (m, 18 H, CH2), 2.03 (dd, J = 12.4,
5.6 Hz, 1 H, CH2CHN), 2.09 (q, J = 7.0 Hz, 2 H, CH2CH=CH),
2.98 (ddd, J = 12.4, 4.9, 1.7 Hz, 1 H, CH2CHN), 4.07 (d, J =
12.5 Hz, 1 H, CH2N), 4.16 (s, 2 H, CH2O), 4.33 (d, J = 12.5 Hz, 1
H, CH2N), 4.56–4.70 (s, 2 H, CHO, CHN), 5.62 [dd, J = 15.5(E),
3.8 Hz, 1 H, CH=CHCHO], 5.80 (s, 1 H, =CHCH2N), 5.86 [dt, J
= 15.5(E), 7.0 Hz, 1 H, CH=CHCHO], 7.30–7.58 (m, 5 H,
arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = 14.4 (CH3), 23.0,
29.4, 29.5, 29.6, 29.8, 29.9, 30.0, 30.1, 32.2, 32.9, 34.9, 42.8 (CH2),
42.8 (CHN), 64.9 (CH2O), 72.6 (CHO), 114.5 (=CHCH2N), 125.7,
127.7, 129.4 (CH arom.), 128.4 (CH=CHCHO), 131.4 (Cq arom.),
133.8 (Cq-CH2O), 135.5 (CH=CHCHO), 152.1, 152.7 (C=O) ppm.
syn-11Јa: Brown oil. Rf = 0.67 (PE/EtOAc, 50:50). 1H NMR
(300 MHz, CDCl3): δ = 0.88 (t, J = 6.6 Hz, 3 H, CH3), 1.16–1.44
(m, 18 H, CH2), 1.70 (dt, J = 12.4, 11.5 Hz, 1 H, CH2CHN), 2.02
(q, J = 6.8 Hz, 2 H, CH2CH=CH), 2.86 (ddd, J = 12.4, 4.9, 1.7 Hz,
1 H, CH2CHN), 4.04–4.13 (m, 2 H, CH2N, CHN), 4.18 (s, 2 H,
CH2O), 4.35 (d, J = 12.4 Hz, 1 H, CH2N), 4.50 (d, J = 11.5 Hz, 1
H, CHO), 5.46 [dd, J = 15.4(E), 6.2 Hz, 1 H, CH=CHCHO], 5.76
[dt, J = 15.4(E), 6.8 Hz, 1 H, CH=CHCHO], 5.84 (s, 1 H,
=CHCH2N), 7.30–7.56 (m, 5 H, arom.) ppm. 13C NMR (75 MHz,
CDCl3): δ = 14.4 (CH3), 23.0, 29.3, 29.5, 29.7, 29.8, 29.9, 30.0,
30.1, 32.2, 32.6, 38.4, 42.9 (CH2), 54.9 (CHN), 70.5 (CH2O), 76.6
(CHO), 115.5 (=CHCH2N), 125.8, 128.7, 129.5 (CH arom.), 128.5
(CH=CHCHO), 130.4 (Cq arom.), 132.6 (Cq-CH2O), 134.2
(CH=CHCHO), 152.2–152.3 (C=O) ppm. HRMS: calcd. for
C28H39N3O3 465.2991; found 465.2990.
General Procedure for Enyne RCM/DA Reaction. Preparation of
Compounds 7/7Ј: Catalyst 1a (97 mg, 5%) was added to a stirred
solution of ether
2 (322 mg, 2.4 mmol) in dichloromethane
(240 mL) and the reaction mixture was heated for 4 h at 40 °C.
After cooling to room temperature, N-phenyltriazole 6 (435 mg,
2.5 mmol) was added and the reaction mixture was stirred for 1 h.
The solvent was then removed and the residue purified by flash
column chromatography (petroleum ether/ethyl acetate, 60:40) to
afford 7 as a brown oil.
Compounds 7/7Ј: Yield 92% (167 mg). Rf = 0.47 (PE/EtOAc, 50:50),
two diastereoisomers: anti-7/syn-7Ј = 57/43. 1H NMR (500 MHz,
CDCl3): δ = 1.70 (dt, J = 12.3, 11.7 Hz, 1 H, CH2CHN syn), 2.08
(td, J = 12.3, 5.7 Hz, 1 H, CH2CHN anti), 2.92 (ddd, J = 12.6, 5.0,
1.9 Hz, 1 H, CH2CHN anti), 3.03 (ddd, J = 12.7, 5.0, 1.9 Hz, 1 H,
CH2CHN syn), 4.13 (d, J = 12.9 Hz, 1 H, CH2N anti), 4.14 (d, J
= 12.6 Hz, 1 H, CH2N syn), 4.18–4.21 (m, 3 H, CH2O, CH2N anti,
syn), 4.34 (d, J = 12.3 Hz, 1 H, CHN syn), 4.38 (d, J = 12.3 Hz, 1
H, CHN anti), 4.54 (d, J = 11.3 Hz, 1 H, CHO syn), 4.64 (d, J =
11.6 Hz, 1 H, CHO anti), 4.66–4.70 (m, 1 H, CH2O), 5.18 (dt, J =
10.7, 1.3 Hz, 1 H, =CH2cis syn), 5.32 (dt, J = 17.3, 1.3 Hz, 1 H,
=CH2trans syn), 5.41 (dd, J = 11.0, 2.2 Hz, 1 H, =CH2cis anti), 5.47
(dd, J = 17.6, 1.3 Hz, 1 H, =CH2trans anti), 5.82 (s, 1 H, =CHCH2N
anti), 5.85 (ddd, J = 17.3, 10.7, 5.0 Hz, 1 H, CH2=CH syn), 5.86
(s, 1 H, =CHCH2N syn), 6.00 (ddd, J = 17.6, 11.0, 3.5 Hz, 1 H,
CH2=CH anti), 7.33–7.58 (m, 5 H, arom.) ppm. 13C NMR
(75 MHz, CDCl3): δ = 33.9 (CH2CHN anti), 37.6 (CH2CHN syn),
42.4 (CH2N), 51.3 (CHN anti), 54.4 (CHN syn), 64.7 (CH2O anti),
70.0 (CH2O syn), 72.3 (CHO anti), 75.8 (CHO syn), 114.4
(=CHCH2N anti), 115.3 (=CHCH2N syn), 115.9, 118.2 (=CH2
anti, syn), 125.3, 128.0, 129.1 (CH arom.), 131.3, 131.8, 132.9 (Cq
arom., Cq-CH2O anti, syn), 136.3, 136.8 (CH2=CH anti, syn),
151.7, 152.3 (C=O) ppm. HRMS: calcd. for C17H17N3O3 311.1270;
found 311.1271.
Compounds 11b/11Јb: Obtained from compounds 7/7Ј and alkene
10b. Yield 74% (140 mg). anti/syn = 60/40. anti-11b: Brown oil. Rf
Compounds 9/9Ј: Obtained from ether 2 and 8 as a brown oil. Yield
59% (123 mg). Rf = 0.38 (PE/EtOAc, 70:30). H NMR (500 MHz,
1
1
= 0.67 (PE/EtOAc, 50:50). H NMR (300 MHz, CDCl3): δ = 0.03
CDCl3): δ = 1.17–1.38 (m, 6 H, CH3), 1.98–2.19 (m, 1 H,
(s, 3 H, CH3Si), 0.08 (s, 3 H, CH3Si), 0.90 [s, 9 H, (CH3)3CSi],
CH2CHN), 2.23–2.43 (m, 1 H, CH2CHN), 3.63 (d, J = 15.6 Hz, 1 1.50–1.72 (m, 2 H, CH2CH2CH2), 2.06 (dt, J = 12.5, 3.8 Hz, 1 H,
H, CHN), 3.94 (d, J = 12.0 Hz, 1 H, CH2N), 4.09–4.32 (m, 5 H, CH2CHN), 2.17 (q, J = 7.2 Hz, 2 H, CH2CH2CH=), 2.98 (ddd, J
CH2CH3, CH2N), 4.47–4.62 (m, 2 H, Cq-CH2O), 4.66–4.88 (m, 1
H, CHO), 5.39 (d, J = 10.9 Hz, 1 H, =CH2cis), 5.44 (d, J = 17.5 Hz,
= 12.5, 4.9, 2.1 Hz, 1 H, CH2CHN), 3.62 (t, J = 6.4 Hz, 2 H, Si-
OCH2), 4.08 (d, J = 12.4 Hz, 1 H, CH2N), 4.18 (s, 2 H, CH2O),
1 H, =CH2trans), 5.70 (s, 1 H, =CHCH2N), 5.98 (ddd, J = 17.5, 4.34 (d, J = 12.5 Hz, 1 H, CH2N), 4.56–4.73 (m, 2 H, CHO, CHN),
10.9, 3.5 Hz, 1 H, CH=CH2) ppm. 13C NMR (75 MHz, CDCl3): δ 5.65 [dd, J = 15.9(E), 3.9 Hz, 1 H, CH=CHCHO], 5.82 (s, 1 H),
= 14.7 (CH3), 34.2 (CH2CHN), 42.8 (CH2N), 50.5 (CHN), 62.3,
5.88 [dt, J = 15.9(E), 7.2 Hz, 1 H, CH=CHCHO], 7.31–7.60 (m, 5
62.4 (CH2CH3), 66.0 (Cq-CH2O), 73.4 (CHO), 117.6 (=CHCH2N), H arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = –5.0 (CH3Si), 18.6
118.0 (=CH2), 128.2 (Cq-CH2O), 136.8 (CH2=CH), 155.2, 155.5 (Cq-Si), 26.2 [(CH3)3CSi], 29.2, 32.2, 34.8, 42.7 (CH2), 51.8 (CHN),
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Polycyclic Compounds by a New Three-Component Reaction
FULL PAPER
62.7 (CH2Si), 64.9 (CH2O), 72.5 (CHO), 114.5 (=CHCH2N), 125.7, 152.1, 152.8 (C=O) ppm. syn-11Јd: Brown oil. Rf = 0.40 (PE/
128.0, 129.4 (CH arom.), 128.4 (CH=CHCHO), 131.3 (Cq arom.), EtOAc, 50:50). 1H NMR (300 MHz, CDCl3): δ = 1.67 (dt, J =
133.6 (Cq-CH2O), 134.8 (CH=CHCHO), 152.1, 152.7 (C=O) ppm.
syn-11Јb: Brown oil. Rf = 0.49 (PE/EtOAc, 50:50). 1H NMR
(300 MHz, CDCl3): δ = 0.03 (s, 3 H, CH3Si), 0.10 (s, 3 H, CH3Si),
12.4, 11.5 Hz, 1 H, CH2CHN), 2.90 (ddd, J = 12.4, 4.9, 1.8 Hz, 1
H, CH2CHN), 3.93 (d, J = 7.6 Hz, 2 H, CH2Br), 4.10 (d, J =
12.8 Hz, 1 H, CH2N), 4.18 (s, 2 H, CH2O), 4.19 (s, 1 H, CHN),
0.88 [s, 9 H, (CH3)3CSi], 1.53–1.64 (m, 2 H, CH2CH2CH2), 1.70 4.38 (d, J = 12.8 Hz, 1 H, CH2N), 4.50 (d, J = 11.5 Hz, 1 H, CHO),
(dt, J = 12.4, 11.5 Hz, 1 H, CH2CHN), 2.10 (q, J = 7.0 Hz, 2 H, 5.76 [dd, J = 15.3(E), 5.1 Hz, 1 H, CH=CHCHO], 5.86 (s, 1 H,
CH2CH2CH=), 2.85 (ddd, J = 12.4, 4.9, 1.7 Hz, 1 H, CH2CHN), =CHCH2N), 5.98 [dt, J = 15.3(E), 7.6 Hz, 1 H, CH=CHCHO],
3.60 (t, J = 6.4 Hz, 2 H, SiOCH2), 4.04–4.14 (m, 2 H, CHN, 7.33–7.62 (m, 5 H, arom.) ppm. 13C NMR (75 MHz, CDCl3): δ =
CH2N), 4.18 (s, 2 H, CH2O), 4.33 (d, J = 12.4 Hz, 1 H, CH2N), 31.9, 37.9, 42.8 (CH2), 54.7 (CHN), 70.5 (CH2O), 74.9 (CHO),
4.51 (d, J = 11.5 Hz, 1 H, CHO), 5.48 [dd, J = 15.4(E), 6.1 Hz, 1
H, CH=CHCHO], 5.77 [dt, 15.4(E), 7.0 Hz, H,
115.9 (=CHCH2N), 125.7 (CH=CHCHO), 125.8, 128.1, 129.5 (CH
arom.), 128.5 (Cq arom.), 132.1 (Cq-CH2O), 133.6 (CH=CHCHO),
152.0, 152.1 (C=O) ppm. HRMS: calcd. for C18H18BrN3O3 – H+
403.0532; found 403.0533.
J
=
1
CH=CHCHO], 5.84 (s, 1 H), 7.30–7.58 (m, 5 H, arom.) ppm. 13C
NMR (75 MHz, CDCl3): δ = –4.9 (CH3Si), 18.6 (Cq-Si), 26.3
[(CH3)3CSi], 28.9, 32.3, 38.4, 42.8 (CH2), 54.9 (CHN), 62.7
(CH2Si), 70.5 (CH2O), 76.4 (CHO), 115.5 (=CHCH2N), 125.8,
128.5, 129.4 (CH arom.), 129.0 (CH=CHCHO), 131.4 (Cq arom.),
132.6 (Cq-CH2O), 133.5 (CH=CHCHO), 152.2, 152.6 (C=O) ppm.
HRMS: calcd. for C26H37N3O4Si+H+ 484.2632; found 484.2632.
Compound 14b: Obtained from compound 13 and alkene 10b as a
brown oil. Yield 82% (75 mg). Rf = 0.71 (PE/EtOAc, 50:50). 1H
NMR (500 MHz, CDCl3): δ = 0.02 (s, 6 H, CH3Si), 0.87 [s, 9 H,
(CH3)3CSi], 1.63 (quint, J = 7.0 Hz, 2 H, CH2CH2CH2), 2.15 (q, J
= 6.9 Hz, 2 H, CH2CH=CH), 3.61 (t, J = 6.4 Hz, 2 H, CH2OSi),
4.05 (dt, J = 16.4, 2.3 Hz, 1 H, CH2O), 4.14 (d, J = 5.0 Hz, 1 H,
CHO), 4.43 (dt, J = 16.4, 2.8 Hz, 1 H, CH2O), 4.45–4.51 (m, 2 H,
CH2N, CHN), 4.56 (d, J = 12.0 Hz, 1 H, CH2N), 5.84 (s, 1 H,
CHCH2N), 5.93 [dt, J = 15.4(E), 6.3 Hz, 1 H, CH=CHCHO], 5.98
[dd, J = 15.4(E), 5.0 Hz, 1 H, CH=CHCHO], 7.30–7.55 (m, 5 H,
arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = –5.0 (CH3Si), 18.6
(Cq-Si), 26.2 [(CH3)3CSi], 28.9, 32.4 (CH2), 42.9 (CH2N), 62.7
(CHN), 62.9 (CH2OSi), 68.0 (CH2O), 82.1 (CHO), 113.0
(CHCH2N), 125.9, 128.6, 129.5 (CH arom.), 128.1 (CH=CHCHO),
129.6 (Cq arom.), 134.2 (CH=CHCHO), 137.2 (Cq-CH2O), 152.1,
Compounds 11c/11Јc: Obtained from compounds 7/7Ј and alkene
10c. Yield 66% (152 mg). anti/syn = 55/45. anti-11c: Brown oil. Rf
1
= 0.40 (PE/EtOAc, 50:50). H NMR (300 MHz, CDCl3): δ = 2.05
(dt, J = 12.6, 5.8 Hz, 1 H, CH2CHN), 2.98 (ddd, J = 12.6, 4.9,
2.0 Hz, 1 H, CH2CHN), 3.20 (d, J = 7.0 Hz, 2 H, CH2C=O), 4.05
(d, J = 12.6 Hz, 1 H, CH2N), 4.15 (s, 2 H, CH2OCH), 4.28 (d, J
= 12.6 Hz, 1 H, CH2N), 4.54 (d, J = 11.7 Hz, 1 H, CHO), 4.64 (s,
1 H, CHN), 5.10 (s, 2 H, CH2–Ph), 5.75 [dd, J = 16.1(E), 3.6 Hz,
1 H, CH=CHCHO], 5.77 (s, 1 H, =CHCH2N), 5.98 [dt, J =
16.1(E), 7.0 Hz, 1 H, CH=CHCHO], 7.28–7.40 (m, 5 H, arom.),
7.42–7.58 (m, 5 H, arom.) ppm. 13C NMR (75 MHz, CDCl3): δ =
34.8, 38.0, 42.6 (CH2), 51.6 (CHN), 64.9 (CH2O), 66.8 (BnOCH2)
71.9 (CHO), 114.6 (=CHCH2N), 125.6, 126.2, 128.3, 128.5, 128.6,
128.8, 129.3 (CH arom., CH=CHCHO), 131.3 (Cq arom.), 132.4
(Cq-CH2O), 133.3 (CH=CHCHO), 135.9 (Cq arom.), 151.9, 152.7
(C=O), 171.2 (C=O) ppm. syn-11Јc: Brown oil. Rf = 0.35 (PE/
EtOAc, 50:50). 1H NMR (300 MHz, CDCl3): δ = 1.70 (dt, J =
12.2, 11.7 Hz, 1 H, CH2CHN), 2.89 (ddd, J = 12.2, 4.9, 1.7 Hz, 1
H, CH2CHN), 3.13 (d, J = 7.0 Hz, 2 H, CH2C=O), 4.11 (d, J =
12.4 Hz, 1 H, CH2N), 4.07–4.22 (m, 3 H, CHN, CH2OCH), 4.37
(d, J = 12.4 Hz, 1 H, CH2N), 4.51 (d, J = 11.7 Hz, 1 H, CHO),
5.10 (s, 2 H, CH2Ph), 5.62 [dd, J = 15.6(E), 5.6 Hz, 1 H,
CH=CHCHO], 5.86 (s, 1 H, =CHCH2N), 5.91 [dt, J = 15.6(E),
7.0 Hz, 1 H, CH=CHCHO], 7.29–7.42 (m, 5 H, arom.), 7.43–7.57
(m, 5 H, arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = 37.9, 38.0,
42.8 (CH2), 54.7 (CHN), 66.8 (BnOCH2), 70.4 (CH2O), 75.6
(CHO), 115.7 (=CHCH2N), 124.6, 125.7, 128.4, 128.5, 128.6,
128.8, 129.4 (CH arom., CH=CHCHO), 129.3, 131.3 (Cq arom.),
132.3 (Cq-CH2O), 132.8 (CH=CHCHO), 152.1, 152.5 (C=O),
171.2 (C=O) ppm. HRMS: calcd. for C26H25N3O5 459.1794; found
459.1792.
153.7 (C=O) ppm. HRMS: calcd. for C25H35N3O4Si + H+
470.2475; found 470.2472.
=
Compound 14c: Obtained from compound 13 and alkene 10c as a
brown oil. Yield 53% (51 mg). Rf = 0.44 (PE/EtOAc, 50:50). 1H
NMR (500 MHz, CDCl3): δ = 3.20 (t, J = 6.3 Hz, 2 H, CH2C=O),
4.05 (dt, J = 16.7, 2.2 Hz, 1 H, CH2O), 4.12 (d, J = 5.0 Hz, 1 H,
CHO), 4.43 (dt, J = 16.7, 2.6 Hz, 1 H, CH2O), 4.49 (d, J = 12.3 Hz,
1 H, CH2N), 4.50–4.54 (m, 1 H, CHN), 4.57 (d, J = 12.3 Hz, 1 H,
CH2N), 5.10 (s, 2 H, CH2Ph), 5.83 (s, 1 H, =CHCH2N), 6.09 [dt,
J = 15.4(E), 7.0 Hz, 1 H, CH=CHCHO], 6.24 [dd, J = 15.4(E),
5.0 Hz, 1 H, CH=CHCHO], 7.27–7.40 (m, 5 H, arom.), 7.43–7.55
(m, 5 H, arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = 37.9, 42.9
(CH2), 62.6 (CHN), 66.7, 68.2 (CH2O, BnOCH2), 81.2 (CHO),
113.2 (=CHCH2N), 124.7 (CH=CHCHO), 125.7, 128.4, 128.5,
128.6–128.8, 129.5 (CH arom.), 131.2 (Cq arom.), 132.1
(CH=CHCHO), 136.1, 136.2 (Cq-CH2O, Cq arom.), 152.0, 153.9
(C=O), 171.5 (C=O) ppm. HRMS: calcd. for C25H23N3O5 + H+
446.1716; found 446.1714.
=
General Procedure for RCM/CM/DA, Method A. Preparation of
Compound 14e: Catalyst 1a (21 mg, 5%) was added to a stirred
solution of ether 3 (61 mg, 0.5 mmol) and alkene 10e (0.29 mL,
2.5 mmol) in dichloromethane (50 mL). The reaction mixture was
heated for 4 h at 40 °C. After cooling to room temperature, N-
phenyltriazole 6 (96 mg, 0.55 mmol) was added and the reaction
mixture was stirred for 1 h. The solvent was removed and the resi-
due purified by flash column chromatography (petroleum ether/
ethyl acetate, 60:40) to afford 14e as a brown oil in a yield of 32%.
Compounds 11d/11Јd: Obtained from compounds 7/7Ј and alkene
10d. Yield 52% (52 mg). anti/syn = 56:44. anti-11d: Brown oil. Rf
1
= 0.42 (PE/EtOAc, 50:50). H NMR (300 MHz, CDCl3): δ = 2.10
(dt, J = 12.4, 5.6 Hz, 1 H, CH2CHN), 2.98 (ddd, J = 12.4, 4.9,
1.9 Hz, 1 H, CH2CHN), 4.00 (d, J = 7.2 Hz, 2 H, CH2Br), 4.12 (d,
J = 12.8 Hz, 1 H, CH2N), 4.17 (s, 2 H, CH2O), 4.32 (d, J = 12.8 Hz,
1 H, CH2N), 4.56 (d, J = 11.9 Hz, 1 H, CHO), 4.68 (s, 1 H, CHN),
5.82 (s, 1 H, =CHCH2N), 5.93 [dd, J = 15.6(E), 3.3 Hz, 1 H, Rf = 0.27 (PE/EtOAc, 50:50). 1H NMR (300 MHz, CDCl3): δ =
CH=CHCHO], 6.10 [dt, J = 15.6(E), 7.2 Hz, 1 H, CH=CHCHO],
7.32–7.59 (m, 5 H, arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = H, CH2CH2CH=), 3.41 (t, J = 6.9 Hz, 2 H, CH2Br), 3.96–4.24 (m,
31.9, 34.8, 42.7 (CH2), 51.7 (CHN), 65.3 (CH2O), 71.6 (CHO), 2 H, CH2N), 4.32–4.64 (m, 4 H, CH2O, CHO, CHN), 5.82 (s, 1 H,
115.0 (=CHCH2N), 125.7 (CH=CHCHO), 128.5, 129.5, 130.3 (CH CHCH2N), 5.88 [dt, J = 15.4(E), 6.6 Hz, 1 H, CH=CHCHO], 6.04
arom.), 131.3 (Cq arom.), 133.1 (Cq-CH2O), 133.4 (CH=CHCHO), [dd, J = 15.4(E), 5.1 Hz, 1 H, CH=CHCHO], 7.30–7.66 (m, 5 H,
1.96 (quint, J = 7.0 Hz, 2 H, CH2CH2CH2). 2.24 (q, J = 6.7 Hz, 2
Eur. J. Org. Chem. 2007, 1606–1612
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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1611

M.-A. Virolleaud, O. Piva
FULL PAPER
arom.) ppm. 13C NMR (75 MHz, CDCl3): δ = 30.9, 32.1, 33.5
(CH2), 42.9 (CH2N), 62.5 (CHN), 68.0 (CH2O), 81.9 (CHO), 113.1
(CHCH2N), 125.8, 128.5, 128.9 (CH arom.), 129.4 (CH=CHCHO),
131.1 (Cq arom.), 132.2 (CH=CHCHO), 137.0 (Cq-CH2O), 152.0,
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General Procedure for RCM/DA/CM, Method B. Preparation of
Compound 11a/11Јa: Catalyst 1a (10 mg, 5%) was added to a stirred
solution of ether 2 (35 mg, 0.26 mmol) in dichloromethane (26 mL)
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Received: October 30, 2006
Published Online: February 9, 2007
1612
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Eur. J. Org. Chem. 2007, 1606–1612