Silver versus gold catalysis in tandem reactions of carbonyl functions onto alkynes: A versatile access to furoquinoline and pyranoquinoline cores

Article abstract of DOI:10.1002/chem.200700202

An efficient and versatile tandem process of acetalization and cycloisomerization reactions has been developed for the reactions of 1-alkynyl-2-carbonyl-quinoline substrates. The reaction occurs thanks to Au ¹ and Ag¹ catalysis. Silver(I) catalysis has been extensively studied (11 different silver species) on a broad range of quinoline derivatives (variation of alkyne substituent, of carbonyl function and of nucleophiles), leading to a variety of furoquinoline and pyranoquinoline moieties. An insight is given for the presumed mechanism along with DFT-B3LYP/6-31G** calculations to address the 6-endo and 5-exo regioselectivities observed.

Full text of DOI:10.1002/chem.200700202

DOI: 10.1002/chem.200700202
Silver versus Gold Catalysis in Tandem Reactions ofCarbonyl Functions onto
Alkynes: A Versatile Access to Furoquinoline and Pyranoquinoline Cores
Thomas Godet,[a] Carine Vaxelaire,[a] Carine Michel,[b] Anne Milet,[b] and
Philippe Belmont*[a]
Abstract: An efficient and versatile tandem process of acetalization and cycloiso-
merization reactions has been developed for the reactions of 1-alkynyl-2-carbonyl-
quinoline substrates. The reaction occurs thanks to AuI and AgI catalysis. Silver(I)
catalysis has been extensively studied (11 different silver species) on a broad range
of quinoline derivatives (variation of alkyne substituent, of carbonyl function and
of nucleophiles), leading to a variety of furoquinoline and pyranoquinoline moiet-
ies. An insight is given for the presumed mechanism along with DFT-B3LYP/6–
31G** calculations to address the 6-endo and 5-exo regioselectivities observed.
Keywords: acetalization
isomerization · gold · quinolines ·
silver · tandem reactions
·
cyclo-
AHCTREUNG
Introduction
derived structures (Scheme 1) has been extensively studied
with various activating species such as IPy2BF4,[3] I2,[4] ICl,[4]
NBS,[4] PhSeBr,[4] p-NO2C6H4SCl,[4] PdII,[5] CuII or CuI,[6a]
Furoquinoline (furo[2,3-b]quinoline, shown here) and pyra-
A
noquinoline derivatives are alkaloids isolated mainly from
rutaceous plants.[1] Many efforts are
still being made in order to isolate
new family members due to their
broad biological properties, which in-
clude antiplatelet aggregation, anti-
fungal, insecticide, antibacterial, antimicrobial, analgesic, an-
tipyretic and also cytotoxic properties.[1] We recently devel-
oped a base-catalyzed reaction that allowed the formation
Scheme 1. Carbonyl groups addition on alkynes.
of 1,3-dihydro-furo[3,4-b]quinoline derivatives through a 5-
U
PdII/CuII,[6b] AuI or AuIII,[7] and various other metallic salts
(W, Pt, Ru).[5c] Upon activation of the alkyne group, oxygen-
ated functions, among others, have been studied for their
ability to target activated alkynes.[8] Carbonyl groups are of
particular interest, since tandem reactions with nucleophiles
can occur at this function, broadening the structural panel
of the products formed (Scheme 1).[3–7] Although recent de-
velopments in gold chemistry include activation of al-
kynes,[7–9] to the best of our knowledge this tandem reaction
(Scheme 1) has received little interest under the aspect of
gold catalysis.[10] A publication from Li[11a] reported a cas-
cade alkynylation/cyclization catalyzed with a phosphane–
AuI complex, and related work on a a,b-unsaturated ket-
Due to limitations of this methodology we searched for
an original method with an extended scope. Electrophilic ac-
tivation (with organic or metallic species) of related alkynyl-
[a] T. Godet, C. Vaxelaire, Dr. P. Belmont
Institut de Chimie et Biochimie MolØculaires et SupramolØculaires
ICBMS, UniversitØ Claude Bernard, Lyon I. UMR CNRS 5246
Bâtiment CPE, 43 boulevard du 11 Novembre 1918
69622 Villeurbanne cedex (France)
Fax : (+33) 472-432-963
E-mail: belmont@cpe.fr
[b] C. Michel, Prof. Dr. A. Milet
DØpartement de Chimie MolØculaire
AHCTREUNG
DCM, UMR CNRS 5250, UniversitØ Joseph Fourier
Grenoble 1, BP53, 38041 Grenoble cedex 9 (France)
acetalization/cycloisomerization reactions of quinoline sub-
strates. However, the main interest of this paper is to inves-
Supporting information for this article is available on the WWW
under http://www.chemeurj.org/ or from the author.
5632
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2007, 13, 5632 – 5641

FULL PAPER
Table 2. Diversity in silver catalysis.[a]
tigate and empower the novel use of silver catalysts in such
reactions in order to reach furoquinoline and pyranoquino-
line cores.
[c]
[Ag]
Reaction
time [h]
5-exo-dig
6-endo-dig
product 3[b]
pKa
complex
product 2[b]
1AgSbF
2
2
4
0.75
3
15
2
12
2
0.16
0.5
1
1
<0
<0
<0
<0
2
00
00
6
2
3
4
5
6
AgPF6
AgOTf
AgNO3
Ag2SO4
AgF
100
100
95
3.2
60
52
Results and Discussion
5
95
40
We first investigated AuI and AuIII tandem acetalization/cy-
7
8
9
1
AgOCN
AgOAc
Ag2CO3
2OAg
3.7
cloisomerization catalysis on quinoline derivative
1
(Table 1),[12] easily amenable in one step from commercially
available 2-chloro-3-quinoline carboxaldehyde.[12b]
48
4.8
10.3
15.7
15.7
100
100
100
0
11
AgO
Table 1. [Au]-catalyzed tandem acetalization/cycloisomerization.[a]
[a] 0.05m reaction mixture in MeOH and [Ag] 5 mol%. [b] Ratio be-
tween 2 and 3, estimated by 1H NMR analysis. [c] pKa values of silver
counterion.[18]
(Table 2, entry 1–4) allow an efficient transformation of
quinoline derivative 1 to the 6-endo-dig product 3. With
Ag2SO4 and AgF (Table 2, entry 5 and 6) a 95:5 ratio be-
tween cyclized derivative 3:2 was observed. A second group,
AgOCN and AgOAc (Table 2, entry 7 and 8), led to poor or
no selectivity between products 2 and 3 (ratio 40:60 and
48:52, respectively). Finally, for the last group of silver salts,
Ag2CO3, Ag2O, and AgO (Table 2, entry 9–11), the selectivi-
ty was reversed from that of the first group, since the only
compound detected was the 5-exo-dig product 2.
Catalyst (5 mol%)
Product
1[d]
3
3
3
Conv.[%][c]
1AuCl
–
25
>95
>95
3
2
3
4
A
N
[b]
A
N
[a] 0.05m reaction mixture in MeOH. [b] [AuCl(PPh3)] (5 mol%) and
G
AgSbF6 (5 mol%) mixed in situ prior to addition of 1. [c] Conversion cal-
culated by 1H NMR analysis. [d] Contaminated with undetermined com-
pounds.
It appeared that chloride salts AuCl3 (Table 1, entry 1),
with methanol as nucleophile and solvent, did not catalyzed
the formation of furoquinolines 2 or pyranoquinolines 3
(Table 1) and only poor conversion (25%) was observed
The first group of silver salts (AgSbF6, AgPF6, AgOTf,
and AgNO3) is known for forming p complexes with al-
kynes,[13,15] thus acting as a transition-metal catalyst[16] and
we can assume that the same reactivity occurs with AgF and
Ag2SO4, since they give the same regioselectivity upon reac-
tion with quinoline 1 (Scheme 2, path A). The last group of
silver catalysts group (Ag2CO3, Ag2O, and AgO) are mainly
characterized through their oxidizing properties of oxygen-
ated functions.[17] Therefore, they should interact mainly
with compound 1 by activation of the aldehyde function
(Scheme 2, path B); this may explain the different regiose-
lectivity observed (5-exo versus 6-endo). The second group
of silver salts, AgOCN and AgOAc (Table 2, entry 7 and 8)
may exhibit hybrid activation from the two other groups
which may account for the poor regioselectivity.
with [AuCl
was circumvented with the use of a more reactive gold com-
plex such as [Au(PPh3)]SbF6 ([AuCl
(PPh3)]/AgSbF6),[7j,q,v]
A
A
ACHTREUNG
providing pyranoquinoline 3 with a high conversion rate
(Table 1, entry 3).
Interestingly, a control experiment with AgSbF6 gave re-
sults comparable to the activated gold catalyst (Table 1,
entry 4 vs. entry 3). It should be noted that in most of the lit-
erature reports on gold studies, control experiments are per-
formed with the requisite silver salts used for preparation of
the activated gold catalyst. Usually, the comparative results
are poor[7n] or nonexistent[7p,q] with the silver species, but in
some cases when noticeable yields are observed, the reac-
tion may be much slower,[7j,u] or even faster[7e] than in the
gold-catalyzed reaction. Also, control experiments may pin-
point a different reaction product.[7o]
Also, it is worth noting that the pKa value[18] of the silver
counterion fits fairly well with the regioselectivity observed.
Overall, the nature of the silver salts (lewis acidity, oxidizing
agent, transition-metal properties, type of counter anion)
seems to be determinant for the regioselectivity, so we pre-
sume that the reaction mechanism may be different, and we
propose two reaction pathways (Scheme 2, path A and B)
depending on the silver coordination site.,[5d,6a,7y,11b,13d]
The path A (Scheme 2) accounts for the first silver salts
group (Table 2, entry 1–6), for which upon coordination of
the triple-bond of 1 (intermediate 4) the enhancement of
electrophilicity of the alkyne gives rise to subsequent nucle-
ophilic attack of the carbonyl oxygen atom on the electron-
deficient alkyne to yield the intermediate silver ate complex
5.[7w,z] The solvent/nucleophile MeOH can then attack inter-
Silver catalysis has received less attention and in recent
À
À
work mostly C C and C N bond formation have been re-
ported,[13] and no mention has been made for such direct
tandem acetalization/cycloisomerization reactions with car-
bonyl species. The sole example is one side product reported
by Yamamoto.[14]
Therefore we studied this new reactivity by using a range
of silver catalysts with quinoline derivative 1 as a model sub-
strate (Table 2). The results can be divided in three catego-
ries. First of all, AgSbF6, AgPF6, AgOTf, and AgNO3
Chem. Eur. J. 2007, 13, 5632 – 5641ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5633

P. Belmont et al.
Table 3. Furoquinolines and pyranoquinolines synthesis.[a]
Starting material
Product[b], [Ag] (yield%[c]
)
1
2
3
1
1
4
5
1
1
Scheme 2. Proposed cyclization mechanisms: Paths A and B.
mediate 5, to give intermediate 6, and lead to catalyst recy-
cling and liberation of the 6-endo-dig product 3.
Path B (Scheme 2) can account for reactivity of the last
group of silver catalysts (Table 2, entry 9–11), the oxidative
properties of which direct coordination to the oxygen atom
of the aldehyde function. Thus, intermediate 7 (Scheme 2,
path B) can then lead in turn to the acetal derivative 8,
which cyclizes to give complex 9 and, after catalyst recy-
cling, yields the 5-exo-dig product 2.
AgOTf, Ag2O, and AgOAc catalysts were used to expand
the structural diversity of furo- and pyranoquinolines
(Table 3).[12]
6
7
1
1
Quinoline derivative 1 was treated under AgOTf catalysis
with various alcohol substrates such as methanol, diol (eth-
ylene glycol); poor nucleophiles (trifluoromethanol, hexa-
fluoroisopropanol); and benzylic or hindered secondary and
tertiary alcohols (entries 1–8, Table 3). In all cases, 6-endo-
dig products (3, 10--12, 14--16, 18) were obtained efficiently
(88%–quantitative yields). On the other hand, Ag2O cataly-
sis with methanol, benzylic, and tertiary alcohols (entries 1,
5, 8) gave exclusively 5-exo-dig products (2, 13, 17) in high
yields (94%–quantitative). Modification of the quinoline
ring (entry 9 and 10) or the presence of functionalized or
hindered alkyl-alkynes (entries 11–14) made no difference
in the reactivity. Thus, 6-endo-dig products (20, 22, 25, 28,
30, 32) were obtained with AgOTf catalysis, whereas Ag2O
catalysis led to 5-exo-dig products (24, 27), always in high
yield (85%–quantitative). Interestingly, the reaction con-
ducted with simple or substituted phenylalkynes (entries 15–
18) gave reversed selectivity compared with previous data
8
1
9
10
11
5634
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ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2007, 13, 5632 – 5641

Silver Catalysts
FULL PAPER
nature of the silver salt. Moreover, experiments performed
with model compounds 47 and 50 (entries 19–20) attested
that the presence of the nitrogen on the quinoline ring had
no impact on the reaction course. Finally, the reactions
tested with AgOAc gave as expected mixture of compounds,
in various ratios.[19]
Table 3. (Continued)
Starting material
Product[b], [Ag] (yield%[c]
)
12
The 5-exo versus 6-endo cycloaddition is a long-standing
observation[20] and we tried to rationalize our results through
DFT-B3LYP/6–31G** calculations[21] using Gaussian 03 soft-
ware.[22] If we consider the reactive complex formed be-
tween AgI (AgF) and a phenyl-substituted triple bond
(Figure 1), a slight elongation of the triple bond and defor-
13
14
15
16
Figure 1. Reactive LUMO of modeled compounds with AgF complex.
17
18
mation from the linearity is observed. We note that the co-
ordination of the silver atom is trans to the attacking oxygen
atom, in accordance with the final stereochemistry of the
double bond formed in the 5-exo product. The reactive
LUMO clearly shows a difference of orbital coefficients be-
tween the two acetylenic carbon atoms in agreement with
the reactivity obtained. However, when the CH2OMe sub-
stituent is used, no such difference is observed and only the
natural charge population analysis can explain the reaction
with a difference of 0.1e between the two acetylenic carbon
atoms, the more electrophilic carbon atom leading to the
formation of the 6-endo product.
19
20
Conclusion
We have described a versatile and efficient method with
silver catalysts producing a broad range of functionalized fu-
roquinolines and pyranoquinolines, under smooth reaction
conditions, allowing acetalization/cycloisomerization reac-
tions even with poor and/or hindered nucleophiles. More-
over the methodology is handy, since we can control the re-
giochemistry depending on the type of silver catalyst used.
Besides, the nature of the alkynyl substituent is an impor-
tant factor in the regiochemistry observed. Also, we dis-
closed here an original study to rationalize the regiochemis-
try showing that the coordination of the silver complex to
the triple bond modifies its properties both from an orbital
[a] [Ag] (5 mol%) in a 0.05m reaction mixture. [b] R3-OH (1.2 equiv) in
Cl
(CH2)2Cl or as solvent.[12b] [c] Isolated yield. Quant=quantitative.
ACHTREUNG
(entries 1–14). Indeed 5-exo-dig products (34, 37, 39, 41, 44,
46) were produced under AgOTf catalysis, whereas catalysis
with Ag2O gave only 6-endo-dig products (35, 42). Again,
the tandem reactions occurred in high yields (89–96%).
Also, the presence of an electron-withdrawing or electron-
donating group on the phenyl substituent made no differ-
ence on the selectivity, which seems to be driven by the
Chem. Eur. J. 2007, 13, 5632 – 5641ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5635

P. Belmont et al.
55.8 ppm; MS (TOF ES+): m/z (%): 256 (100) [M+H]+; HRMS (TOF
ES+): m/z calcd for [C15H14NO3]+: 256.0974; found: 256.0982.
and charge point of view and can explain the difference in
reactivity.
Compound 23: This compound was isolated as an brown solid (quantita-
tive). 1H NMR (300 MHz, [D]CHCl3, 258C): d=10.65 (s, 1H), 8.71 (s,
1H), 8.12 (d, 3J
(ddd, 4J(H,H)=1.5 Hz, 3J
(ddd, 4J(H,H)=1.1 Hz, 3J(H,H)=6.8 Hz, 3J
1H), 3.91–3.66 (m, 4H), 1.28 ppm (t, 3J(H,H)=7.2 Hz, 6H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=190.3, 149.9, 142.6, 137.0, 133.0, 129.6,
129.3, 128.8, 128.5, 128.4, 126.9, 91.6, 80.9, 61.4, 15.0 ppm; MS ESI+: m/z
(%): 284 (100) [M+H]+; HRMS (ESI+): m/z calcd for [C17H18NO3]+:
284.1287; found: 284.1287.
A
ACHTREUNG
G
N
ACHTREUNG
Experimental Section
A
G
ACHTREUNG
AHCTREUNG
General information: Unless otherwise noted, all commercial materials
were used without further purification. Methanol and 1,2-dichloroethane
are ACS reagents grade, and were used as received unless otherwise
noted. Silver salts were obtained from Acros and Strem chemicals com-
panies. TLC analysis of reaction mixtures was performed on Merck silica
gel 60 F254 TLC plates. Flash chromatography was carried out on Merck
60 silica gel (32–63 mm). 1H and 13C NMR spectra were recorded with
Bruker ALS-300 and DRX-300 spectrometers and referenced to CDCl3
unless otherwise noted. Low- and high-resolution mass spectra (m/z)
were measured on a Thermo-Finnigan Mat 95XL spectrometer by the
Mass facility operated by the UniversitØ Claude Bernard Lyon 1(UMR
CNRS-UCBL 5246, Lyon), and also by the CNRS Service Central dꢁAna-
lyse (USR CNRS 59, Lyon) on a LCT Waters, electrospray/TOF.
Compound 26: This compound was isolated as a pale yellow solid (95%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.67 (s, 1H), 8.67 (s, 1H),
8.12 (dd, 4J
A
G
ACHTREUNG
1.5 Hz, 3J
6.8 Hz, 3J
6.8 Hz, 3J
A
ACHTREUNG
R
ACHTREUNG
AHCTREUNG
[D]CHCl3, 258C): d=191.3, 150.0, 144.5, 136.8, 132.8, 129.6, 129.1, 128.7,
127.9, 126.2, 105.9, 76.0, 30.5, 28.4 ppm; MS ESI+: m/z (%): 238 (100)
[M+H]+; HRMS (ESI+): m/z calcd [C16H16NO]+: 238.1232; found:
238.1230.
Starting materials were synthesized according to published procedures[23]
and following Scheme 3.
Compound 29: This compound was isolated as a yellow solid (98%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.63 (s, 1H), 8.65 (s, 1H),
8.08 (d, 3J
4J(H,H)=1.5 Hz, 3J
(H,H)=1.1 Hz, 3J(H,H)=7.2 Hz, 3J
1.00 ppm (d, 3J(H,H)=6.8 Hz, 4H); 13C NMR (75 MHz, [D]CHCl3,
A
ACHTREUNG
A
N
ACHTREUNG
A
N
ACHTREUNG
AHCTREUNG
258C): d=191.2, 150.0, 144.4, 136.8, 132.8, 129.5, 129.1, 128.8, 127.8,
126.1, 101.4, 72.8, 30.1, 9.2, 0.3 ppm; MS ES+: m/z (%): 222 (100)
[M+H]+; HRMS (TOF ES+): m/z calcd for [C15H12NO]+: 222.0919;
found: 222.0927.
Scheme 3. Starting materials were synthesized according to published
Compound 31: This compound was isolated as a brown solid (94%). M.p
778C; 1H NMR (300 MHz, [D]CHCl3, 258C): d=10.6 (s, 1H), 8.69 (s,
procedures: i) Villsmeyer–Haack[23a]
;
ii) Sonogashira[23b–d]
;
iii) 1.
Grignard[23c,d], 2. oxidation[23c,d]; iv) Sonogashira.[23b–d]
1H), 8.10 (d, 3J
(ddd, 4J(H,H)=1.5 Hz, 3J
(ddd, 4J(H,H)=1.2 Hz, 3J(H,H)=6.9 Hz, 3J
4J
(H,H)=3.3 Hz, 1H), 4.70–4.55 ( m, 2H), 3.94–3.81
A
ACHTREUNG
G
N
ACHTREUNG
A
G
ACHTREUNG
General procedure for the Sonogashira reaction: CuI (0.025 mmol,
4.5 mg), Pd(PPh3)2Cl2 (0.05 mmol, 35 mg), Et3N (0.6 mL) and the alkyne
G
ACHTREUNG
ACHTREUNG
(m, 1H), 1.92–1.44 ppm (m, 6H); further characterization was consistent
with published data.[23d]
(1.2 mmol) were added under argon to a stirred solution of quinoline
(1mmol) in anhydrous DMF (1mL). The mixture was stirred at room
temperature and monitored by TLC. After evaporation under vacuum,
the crude mixture was purified by column chromatography on silica gel.
Compound 33: This compound was isolated as a yellowish solid (92%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.9 (s, 1H), 8.70 (s, 1H), 8.12
(d, 3J
N
N
(H,H)=8.3 Hz, 1H), 7.85–7.78 (m, 2H), 7.59–7.50 (m, 2H), 7.44 (t, 3J-
(H,H)=7.5 Hz, 1H), 3.93 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3,
Compound 1: This compound was isolated as a brown-reddish solid
(quantitative). 1H NMR (300 MHz, [D]CHCl3, 258C): d=10.66 (s, 1H),
AHCTREUNG
8.71(s, 1H), 8.12 (d,
3J(H,H)=8.3 Hz, 1H), 7.85 (ddd, 4J
(H,H)=8.3 Hz, 1H), 7.62 (ddd, 4J(H,H)=1.1 Hz, 3J
(H,H)=7.9 Hz, 1H), 4.47 (s, 2H), 3.51ppm (s, 3H); 13C NMR (75 MHz,
3J
A
ACHTREUNG
258C): d=192.2, 166.0, 150.2, 144.1, 136.6, 135.0, 132.9, 132.1, 132.0,
130.7, 129.7, 129.4, 129.4, 128.2, 126.5, 122.1, 93.7, 52.6 ppm; MS (TOF
ES+): m/z (%): 316 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for
[C20H14NO3]+: 316.0974; found: 316.0985.
A
N
ACHTREUNG
A
N
ACHTREUNG
ACHTREUNG
[D]CHCl3, 258C): d=190.5, 149.9, 143.1, 137.1, 133.0, 129.6, 129.3, 128.7,
128.3, 126.5, 91.5, 82.5, 60.2, 58.2 ppm; TOF MS ES+: m/z (%): 226
(100) [M+H]+; HRMS (ESI+): m/z calcd for [C14H12NO2]+: 226.0868;
found: 226.0876.
Compound 36: This compound was isolated as a yellow solid (91%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.6 (s, 1H), 8.58 (s, 1H), 8.03
(d, 3J
A
ACHTREUNG
AHCTREUNG
Compound 19: This compound was isolated as a yellow solid (98%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.59 (s, 1H), 8.49 (s, 1H),
7.52 (s, 1H), 7.30 (s, 1H), 4.45 (s, 2H), 4.39 (m, 4H), 3.50 ppm (s, 3H);
13C NMR (75 MHz, [D]CHCl3, 258C): d=191.0, 150.5, 147.3, 146.3, 142.1,
135.6, 127.9, 123.1, 114.5, 114.0, 91.1, 83.2, 65.0, 64.6, 60.7, 58.6 ppm; MS
(TOF ES+): m/z (%): 284 (100) [M+H]+; HRMS (TOF ES+): m/z
calcd for [C16H14NO4]+: 284.0923; found: 284.0921.
130.1, 130.0, 129.8, 129.7, 128.9, 127.0, 126.5 (q, 2J
ACHTREUNG
90.7 ppm; MS (TOF ES+): m/z (%): 326 (100) [M+H]+; HRMS (TOF
ES+): m/z calcd for [C19H11NOF3]+: 326.0793; found: 326.0801.
Compound 38: This compound was isolated as a yellow solid (89%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.9 (s, 1H), 8.65 (s, 1H), 8.11
(d, 3J
(H,H)=1.5 Hz, 3J
(H,H)=1.9 Hz, 3J(H,H)=7.9 Hz, 1H), 7.54 (ddd, 4J
(H,H)=7.9 Hz, 3J(H,H)=8.7 Hz, 1H), 7.35 (ddd, 4J
(H,H)=7.5 Hz, 3J(H,H)=8.3 Hz, 1H), 6.92 (td, 4J(H,H)=0.8 Hz, 3J-
A
N
A
N
ACHTREUNG
Compound 21: This compound was isolated as an orange solid (quantita-
tive). 1H NMR (300 MHz, [D]CHCl3, 258C): d=10.64 (s, 1H), 8.64 (s,
A
N
ACHTREUNG
A
N
ACHTREUNG
1H), 7.83 (d, 3J
(dd, 4J(H,H)=2.6 Hz, 3J
(H,H)=9.0 Hz, 1H), 4.49 (s, 2H), 3.99 (s, 3H),
A
N
A
N
ACHTREUNG
(H,H)=7.5 Hz, 1H), 6.86 (d, 3J
(H,H)=8.7 Hz, 1H), 3.91ppm (s, 3H);
G
A
N
3.54 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=190.4, 163.7,
152.2, 143.8, 136.4, 130.7, 127.2, 122.0, 121.9, 107.0, 91.3, 82.6, 60.3, 58.2,
134.2, 133.2, 131.9, 130.1, 129.7, 129.4, 128.4, 126.8, 121.0, 111.1, 93.2,
5636
www.chemeurj.org
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2007, 13, 5632 – 5641

Silver Catalysts
FULL PAPER
90.2, 56.2 ppm; MS (TOF ES+): m/z (%): 288 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C19H14NO2]+: 288.1025; found: 288.1044.
U
A
ACHTREUNG
ACHTREUNG
A
N
ACHTREUNG
Compound 40: This compound was isolated as a yellow solid (95%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.7 (s, 1H), 8.77 (s, 1H), 8.54
7.2 Hz, 1H), 4.32 (m, 2H), 3.53 (s, 3H), 3.38 ppm (s, 3H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=153.3, 152.9, 149.9, 131.5, 130.6, 129.6,
129.0, 128.5, 127.7, 126.9, 104.4, 97.4, 66.2, 57.8, 55.0 ppm; MS ESI+: m/z
(%): 258 (100) [M+H]+; HRMS (CI): m/z calcd for [C15H16NO3]+:
258.1130; found: 258.1130.
(s, 1H), 8.28 (d, 3J
A
N
7.99–7.90 (m, 3H), 7.67–7.61ppm (m, 2H); 13C NMR (75 MHz,
[D]CHCl3, 258C): d=190.0, 150.1, 148.2, 142.6, 137.8, 137.7, 133.3, 129.7,
129.6, 129.4, 128.9, 128.7, 127.0, 126.6, 124.4, 123.2, 91.9, 87.6 ppm; MS
(TOF ES+): m/z (%): 303 (100) [M+H]+; HRMS (TOF ES+): m/z
calcd for [C18H11N2O3]+: 303.0770; found: 303.0785.
Compound 3: This compound was prepared by method A. It was isolated
as a yellow solid (quantitative). 1H NMR (300 MHz, [D]CHCl3, 258C):
d=8.10 (s, 1H), 8.07 (d, 3J
U
ACHTREUNG
Compound 43: This compound was isolated as an orange solid (96%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.71 (s, 1H), 8.60 (s, 1H),
1.5 Hz, 3J
7.1Hz, 3J
N
G
ACHTREUNG
7.78 (d, 3J
A
G
ACHTREUNG
7.2 Hz, 3J
ACHTREUNG
A
N
A
G
ACHTREUNG
(75 MHz, [D]CHCl3, 258C): d=190.5, 149.9, 163.6, 152.3, 144.4, 136.3,
132.2, 130.7, 130.6, 129.7, 128.7, 128.5, 127.2, 121.8, 121.7, 121.4, 107.0,
95.2, 85.5, 55.8 ppm; IR (neat): n˜ =3362, 2927, 1614, 1505, 1451, 1264,
1160, 1023, 737 cmÀ1; MS ES+: m/z (%): 288 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C19H14NO2]+: 288.1025; found: 288.1043.
3.40 ppm (s, 3H); to confirm that the signal at 4.17 ppm was not a quad-
ruplet, the spectrum was also performed in [D6]acetone: 1H NMR
(300 MHz, [D6]acetone, 258C): d=8.11 (s, 1H), 7.87 (d, 3J
ACHTREUNG
8.7 Hz, 1H), 7.75 (app. d, 3J
1.5 Hz, 3J(H,H)=7.2 Hz, 3J(H,H)=8.3 Hz, 1H), 7.32 (ddd, 4J
0.8 Hz, 3J(H,H)=6.8 Hz, 3J
1H), 3.86 (dd, 2J
(H,H)=7.9 Hz, 1H), 7.51 (ddd, 4J
ACHTREUNG
Compound 45: This compound was isolated as a dark oil. 1H NMR
C
U
ACHTREUNG
(300 MHz, [D]CHCl3, 258C): d=8.39 (s, 1H), 8.03 (d, 3J
ACHTREUNG
U
ACHTREUNG
1H), 7.73 (d, 3J
(H,H)=7.2 Hz, 3J
(H,H)=1.1 Hz, 3J
A
ACHTREUNG
G
ACHTREUNG
3.11 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=158.4, 149.1,
147.3, 135.0, 131.0, 128.2, 127.9, 127.2, 126.2, 122.6, 103.6, 99.8, 71.5, 58.5,
55.9 ppm; IR (neat): n˜ =2918, 2849, 1739, 1618, 1500, 1252, 1139, 1076,
990, 635 cmÀ1; TOF MS ES+: m/z (%): 258 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C15H16NO3]+: 258.1130; found: 258.1146.
A
ACHTREUNG
A
N
ACHTREUNG
2.78 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=192.5, 161.6,
150.6, 144.9, 137.0, 134.2, 133.2, 131.9, 130.1, 129.7, 129.4, 128.4, 126.8,
121.0, 111.1, 93.2, 90.2, 56.2 ppm; MS EI+: m/z (%): 271(100) [ M]+, 256
(64) [MÀCH3]+, 228 (40) [MÀCH3ÀCO]+.
Compound 10: This compound was prepared by method A. It was isolat-
1
ed as a pale oil (quantitative). H NMR (300 MHz, [D]CHCl3, 258C): d=
Compound 47: This compound was isolated as a yellow oil (86%).
8.01(d, 3J
E
N
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.4 (s, 1H), 7.81 (d, 3J-
1H), 7.67 (td, 3J
E
G
4
3
ACHTREUNG
A
8.3 Hz, 4J
U
3.39 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=191.5, 136.2,
133.9, 133.7, 129.0, 127.4, 126.2, 92.5, 82.2, 60.5, 58.0 ppm; MS ES+: m/z
(%): 175 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for [C11H11O2]+:
175.0759; found: 175.0766.
2
2
ACHTREUNG
4.16 (d, J
G
(H,H)=13.9 Hz, 1H), 4.05 (m,
1H), 3.95 (m, 1H), 3.78 (m, 2H), 3.44 ppm (s, 3H); 13C NMR (75 MHz,
[D]CHCl3, 258C): d=156.4, 149.1, 149.0, 134.0, 130.8, 129.0, 128.3, 127.5,
126.3, 122.8, 105.4, 99.9, 72.3, 71.5, 62.2, 59.0 ppm; IR (neat): n˜ =3200,
2919, 2850, 1735, 1461, 1376, 1260, 1079, 635 cmÀ1; MS ES+: m/z (%):
288 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for [C16H18NO4]+:
288.1236; found: 288.1242.
Compound 50: This compound was isolated as an orange oil (89%).
1H NMR (300 MHz, [D]CHCl3, 258C): d=10.6 (s, 1H), 7.93 (dd, 4J-
A
N
(m, 4H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=191.7, 136.1, 134.0,
133.5, 129.3, 128.8, 128.8, 127.5, 122.6, 96.6, 85.2 ppm; MS ES+: m/z
(%): 207 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for [C15H11O]+:
207.0810; found: 207.0821.
Compound 11: This compound was prepared by method A. It was isolat-
ed as
a
3
258C): d=8.08 (d, J
(H,H)=7.9 Hz, 1H), 8.07 (s, 1H), 7.83 (d, 3J
ACHTREUNG
8.3 Hz, 1H), 7.74 (t, 3J
1H), 6.52 (s, 1H), 6.42 (s, 1H), 4.23 (d, 2J
2H), 4.10 (d, 2J
(H,H)=7.2 Hz, 1H), 7.52 (t, 3J
General procedures for the silver(i) catalyzed O-cyclization
AHCTREUNG
Method A: The silver catalyst (5 mol%) was added to a flask charged
with quinoline (0.1mmol) dissolved in the corresponding alcohol (0.05 m
solution in MeOH, tBuOH, ethylene glycol, trifluoroethanol). The flask
was rubber capped and stirred at room temperature (258C) until the re-
action was judged complete by TLC analysis. The crude reaction mixture
was dissolved in dichloromethane and washed three times with a saturat-
ed aqueous solution of NaHCO3. The organic phase was dried over
Na2SO4 and filtered, and the solvents removed under vacuum. If needed,
the residue was loaded on a silica gel column and elution with the appro-
priate mixture of cyclohexane/ethyl acetate yielded the pure cyclized
products.
AHCTREUNG
(75 MHz, [D]CHCl3, 258C): d=155.5, 148.2, 134.3, 130.7, 128.7, 128.0,
127.0, 126.1, 121.0, 105.4, 98.7, 71.7, 65.1, 64.6, 64.2, 63.7, 58.4 ppm; IR
(neat): n˜ =2920, 2851, 1660, 1621, 1498, 1432, 1269, 1178, 1161, 1082,
1035, 771 cmÀ1; MS (TOF ES+): m/z (%): 326 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C16H15F3NO3]+: 326.1004; found: 326.10117.
Compound 12: This compound was prepared by method B. It was isolat-
ed as a pale yellow solid (quantitative). 1H NMR (300 MHz, [D]CHCl3,
258C): d=8.09 (d, 3J(H,H)=7.2 Hz, 1H), 8.08 (s, 1H), 7.87 (dd, 4J-
G
G
G
ACHTREUNG
A
U
ACHTREUNG
Method B: The corresponding alcohol (1.2 equivalents) and then the
silver catalyst (5 mol%) were added to a flask charged with quinoline
(0.1mmol) dissolved in 1,2-dichloroethane (0.05 m solution). The flask
was rubber capped and stirred at room temperature (258C) until the re-
action was judged complete by TLC analysis. The crude reaction mixture
was dissolved in dichloromethane and washed three times with a saturat-
ed aqueous solution of NaHCO3. The organic phase was dried over
Na2SO4 and filtered, and the solvents removed under vacuum. The resi-
due was loaded on a silica gel column and elution with the appropriate
mixture of cyclohexane/ethyl acetate yielded the pure cyclized products.
3
A
U
ACHTREUNG
A
ACHTREUNG
3.48 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=155.0, 149.3,
134.5, 129.0, 128.1, 127.0, 126.3, 119.7, 105.3, 99.0, 71.2, 58.8, 29.7, 26.9,
14.1 ppm; MS ESI+: m/z (%): 394 (100) [M+H]+; HRMS (ESI+): m/z
calcd for [C17H14F6NO3]+: 394.0878; found: 394.0884.
Compound 13: This compound was prepared by method B. It was isolat-
ed as a yellow solid (94%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=
8.16 (s, 1H), 8.14 (d, 3J
3J
(H,H)=8.3 Hz, 1H), 7.55 (ddd, 4J
(H,H)=8.3 Hz, 1H), 7.34 (d, 3J(H,H)=8.3 Hz, 2H), 7.30 (d, 3J
A
ACHTREUNG
N
N
ACHTREUNG
Compound 2: This compound was prepared by method A. It was isolated
as a light yellow solid (quantitative). 1H NMR (300 MHz, [D]CHCl3,
U
N
ACHTREUNG
258C): d=8.21(s, 1H), 8.61 (d,
3J
A
E
U
ACHTREUNG
Chem. Eur. J. 2007, 13, 5632 – 5641ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5637

P. Belmont et al.
8.7 Hz, 2H), 6.63 (s, 1H), 5.96 (t, 3J
G
): m/z (%): 316 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for
A
[C17H18NO5]+: 316.1185; found: 316.1193.
Compound 14: This compound was prepared by method B. It was isolat-
ed as a yellow solid (93%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=
Compound 22: This compound was prepared by method A. It was isolat-
ed as a light yellow solid (quantitative). 1H NMR (300 MHz, [D]CHCl3,
258C): d=7.91(s, 1H), 7.65 (d, 3J
U
ACHTREUNG
8.01(dd, 4J
4J(H,H)=1.1 Hz, 3J
(H,H)=6.8 Hz, 3J(H,H)=7.2 Hz, 1H), 7.45 (ddd, 4J
(H,H)=6.8 Hz, 4J(H,H)=7.2 Hz, 1H), 7.32 (d, 3J
(H,H)=8.7 Hz, 2H),
7.90 (d, 3J(H,H)=9.0 Hz, 2H), 6.44 (d, 4J
(H,H)=0.8 Hz, 1H), 6.32 (s,
1H), 4.85 (dd, 2J(H,H)=11.7 Hz, 2J(H,H)=23.7 Hz, 2H), 4.11 (ddd, 4J-
(H,H)=0.8 Hz, 3J(H,H)=13.6 Hz, 2J
(H,H)=27.5 Hz, 2H), 3.81(s, 3H),
A
ACHTREUNG
2.6 Hz, 1H), 7.10 (dd, 3J
A
A
N
ACHTREUNG
1H), 6.17 (s, 1H), 4.20 (d, 2J
A
ACHTREUNG
A
N
ACHTREUNG
12.8 Hz, 1H), 3.93 (s, 3H), 3.60 (s, 3H), 3.46 ppm (s, 3H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=161.4, 156.1, 150.5, 149.0, 133.2, 128.8,
122.2, 119.0, 106.7, 104.7, 100.1, 71.8, 58.4, 55.6, 55.5 ppm; IR (neat): n˜ =
2918, 2850, 1636, 1503, 1452, 1378, 1245, 1145, 1083, 996, 958, 790,
633 cmÀ1; MS (TOF ES+): m/z (%): 288.1(100) [ M+H]+; HRMS (TOF
ES+): m/z calcd for [C16H18NO4]+: 288.1236; found: 288.1252.
A
N
ACHTREUNG
A
ACHTREUNG
A
ACHTREUNG
A
N
ACHTREUNG
3.47 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=159.5, 156.3,
149.1, 148.8, 133.3, 130.1, 129.8, 129.0, 128.8, 127.9, 127.2, 125.6, 122.7,
113.9, 104.9, 97.4, 71.8, 69.4, 58.4, 55.3 ppm; IR (neat): n˜ =2923, 2852,
1720, 1618, 1560, 1500, 1432, 1259, 1199, 1086, 1015, 972, 906, 801,
638 cmÀ1; MS (TOF ES+): m/z (%): 364 (100) [M+H]+; HRMS (TOF
ES+): m/z calcd for [C22H22NO4]+: 364.1549; found: 364.1539.
Compound 24: This compound was prepared by method A. It was isolat-
1
ed as a brownish solid (93%). H NMR (300 MHz, [D]CHCl3, 258C): d=
8.20 (s, 1H), 8.14 (d, 3J
U
ACHTREUNG
1H), 7.76 (ddd, 4J
1H), 7.56 (t, 3J
A
(H,H)=6.8 Hz, 3J
ACHTREUNG
C
ACHTREUNG
Compound 15: This compound was prepared by method B. It was isolat-
ed as an orange powder (92%). 1H NMR (300 MHz, [D]CHCl3, 258C):
AHCTREUNG
d=8.06 (s, 1H), 8.03 (d, 3J
U
ACHTREUNG
AHCTREUNG
1.1 Hz, 3J
A
ACHTREUNG
(75 MHz, [D]CHCl3, 258C): d=152.7, 150.0, 131.4, 130.6, 129.8, 128.4,
127.8, 104.7, 98.4, 97.0, 60.9, 60.9, 55.0, 15.3 ppm; MS CI+: m/z (%): 316
(100) [M+H]+; HRMS (CI +): m/z calcd for [C18H22NO4]+: 316.1549;
found: 316.1555.
8.3 Hz, 1H), 7.70 (ddd, 4J
8.7 Hz, 1H), 7.68 (ddd, 4J
C
ACHTREUNG
ACHTREUNG
7.9 Hz, 1H), 7.39 (dd, 4J
A
4J
(H,H)=1.1 Hz, 3J
N
Compound 25: This compound was prepared by method A. It was isolat-
1
A
N
ACHTREUNG
ed as a brownish solid (95%). H NMR (300 MHz, [D]CHCl3, 258C): d=
7.96 (d, 3J
C
ACHTREUNG
A
N
ACHTREUNG
23.7 Hz, 2H), 3.46 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C):
d=156.3, 149.0, 139.4, 139.2, 133.7, 130.3, 129.6, 129.5, 128.8, 128.4, 128.3,
128.0, 127.2, 125.7, 122.3, 104.9, 98.7, 98.3, 74.0, 71.8, 58.5 ppm; IR (neat):
n˜ =2922, 2849, 1722, 1619, 1562, 1497, 1432, 1364, 1229, 1196, 1074, 976,
906, 797, 647 cmÀ1; MS ESI+: m/z (%): 460.0 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C21H19INO3]+: 460.0410; found: 460.0434.
ACHTREUNG
ACHTREUNG
1H), 6.6 (s, 1H), 6.13 (s, 1H), 5.01 (s, 1H), 3.66 (m, 2H), 3.58 (m, 2H),
3.57 (s, 3H), 1.21 ppm (td, 4J(H,H)=1.1 Hz, 3J
(H,H)=7.2 Hz, 6H);
A
ACHTREUNG
13C NMR (75 MHz, [D]CHCl3, 258C): d=155.4, 148.7, 133.6, 130.3, 128.8,
127.9, 127.2, 125.8, 122.7, 104.7, 100.0, 98.7, 62.0, 61.6, 55.8, 15.1 ppm; IR
(neat): n˜ =2973, 2920, 2849, 1651, 1621, 1497, 1433, 1354, 1155, 1114, 997,
965, 754, 637 cmÀ1; MS CI+: m/z (%): 316 (100) [M+H]+; HRMS (CI+):
m/z calcd for [C18H22NO4]+: 316.1549; found: 316.1549.
Compound 16: This compound was prepared by method B. It was isolat-
ed as a pale oil (88%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=8.01
(d, 3J
A
ACHTREUNG
A
N
ACHTREUNG
Compound 27: This compound was prepared by method A. It was isolat-
ed as
a
yellow solid (quantitative). 1H NMR (300 MHz, [D]CHCl3,
G
ACHTREUNG
3
258C): d=8.16 (s, 1H), 8.10 (d, J
(H,H)=8.7 Hz, 1H), 7.83 (d, 3J
ACHTREUNG
R
ACHTREUNG
7.9 Hz, 1H), 7.74 (ddd, 4J
8.7 Hz, 1H), 7.53 (ddd, 4J
(H,H)=1.5 Hz, 3J
(H,H)=0.8 Hz, 3J
G
ACHTREUNG
ACHTREUNG
2.03 (m, 1H), 1.99–1.90 (m, 1H), 1.83–1.70 (m, 2H), 1.61–1.51 (m, 1H),
1.45–1.33 (m, 2H), 1.32–1.20 (m, 2H), 0.92–0.80 ppm (m, 1H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=156.5, 149.3, 133.0, 130.0, 128.7, 127.8,
127.2, 125.5, 123.2, 104.5, 97.2, 77.2, 71.9, 58.4, 33.6, 31.8, 29.7, 25.5, 24.2,
24.0 ppm; MS ESI+: m/z (%): 326 (100) [M+H]+; HRMS (TOF ES+):
m/z calcd for [C20H24NO3]+: 326.1756; found: 326.1744.
G
E
ACHTREUNG
7.9 Hz, 1H), 6.5 (s, 1H), 5.85 (s, 1H), 3.52 (s, 3H), 1.33 ppm (s, 9H);
13C NMR (75 MHz, [D]CHCl3, 258C): d=155.0, 149.8, 148.7, 131.3, 130.4,
129.3, 128.4, 128.2, 127.5, 126.4, 112.1, 103.8, 54.4, 31.8, 30.3 ppm; MS
ES+: m/z (%): 270 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for
[C17H20NO2]+: 270.1494; found: 270.1498.
Compound 18: This compound was prepared by method A. It was isolat-
ed as a pale solid (quantitative). 1H NMR (300 MHz, [D]CHCl3, 258C):
Compound 28: This compound was prepared by method A. It was isolat-
ed as
a
yellow solid (quantitative). 1H NMR (300 MHz, [D]CHCl3,
d=8.01(d, 3J
(H,H)=8.3 Hz, 1H), 7.86 (s, 1H), 7.77 (dd, 4J
ACHTREUNG
3
258C): d=8.14 (s, 1H), 8.08 (d, J
(H,H)=8.3 Hz, 1H), 7.77 (d, 3J
ACHTREUNG
1.3 Hz, 3J
7.2 Hz, 3J
C
N
ACHTREUNG
8.3 Hz, 1H), 7.59 (t, 3J
(H,H)=8.3 Hz, 1H), 7.40 (d, 3J
ACHTREUNG
1H), 6.30 (s, 1H), 6.16 (s, 1H), 3.56 (s, 3H), 1.07 ppm (s, 9H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=172.9, 151.1, 146.7, 136.7, 132.2, 129.0,
127.8, 127.6, 126.8, 123.1, 100.0, 98.9, 56.8, 37.0, 28.1 ppm; IR (neat): n˜ =
2965, 2931, 2359, 1617, 1503, 1436, 1262, 1237, 1157, 1071, 1028, 993, 754,
687 cmÀ1; TOF MS ES+: m/z (%): 270 (100) [M+H]+; HRMS (TOF
ES+): m/z calcd for [C17H20NO2]+: 270.1494; found: 270.1508.
ACHTREUNG
7.2 Hz, 3J
A
ACHTREUNG
1H), 4.11 (ddd, 4J
G
E
ACHTREUNG
2H), 3.45 (s, 3H), 1.41 ppm (s, 9H); 13C NMR (75 MHz, [D]CHCl3,
258C): d=156.9, 149.5, 132.2, 129.7, 128.5, 127.6, 127.1, 125.2, 123.8,
103.9, 94.2, 76.4, 71.7, 58.2, 28.7 ppm; IR (neat): v=2960, 2907, 1632,
1622, 1498, 1433, 1261, 1063, 977, 913, 779, 620 cmÀ1; MS ESI+: m/z
(%): 300 (100) [M+H]+; HRMS (ESI+): m/z calcd for [C18H22NO3]+
300.1599; found: 326.1597.
Compound 30: This compound was prepared by method A. It was isolat-
ed as
[D]CHCl3, 258C): d=7.99 (d, 3J
(d, 3J(H,H)=7.9 Hz, 1H), 7.65 (td, 3J
1H), 7.39 (td, 3J(H,H)=6.8 Hz, 4J
(H,H)=1.1Hz, 1H), 6.26 (s, 1H), 6.08
a pale yellow powder (
quantitative); 1H NMR (300 MHz,
AHCTREUNG
Compound 20: This compound was prepared by method A. It was isolat-
ed as an orange solid (quantitative). 1H NMR (300 MHz, [D]CHCl3,
258C): d=7.77 (s, 1H), 7.45 (s, 1H), 7.17 (s, 1H), 6.35 (s, 1H), 6.13 (s,
A
N
ACHTREUNG
A
ACHTREUNG
(s, 1H), 3.57 (s, 3H), 1.75 (m, 1H), 1.06 (m, 1H), 0.90 ppm (m, 4H);
13C NMR (75 MHz, [D]CHCl3, 258C): d=162.4, 149.8, 148.3, 133.4, 130.2,
128.1, 127.8, 126.6, 125.1, 122.0, 100.8, 99.9, 55.7, 14.8, 7.5, 6.0 ppm; IR
(neat): n˜ =3008, 2919, 2848, 1635, 1617, 1497, 1428, 1078, 1046, 1004, 962,
961, 752, 624 cmÀ1; TOF MS ES+: m/z (%): 254 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C16H16NO2]+: 254.1181; found: 254.1177.
1H), 4.36 (m, 4H), 4.18 (d, 2J
N
N
13 Hz, 1H), 3.59 (s, 3H), 3.44 ppm (s, 3H); 13C NMR (75 MHz,
[D]CHCl3, 258C): d=155.2, 147.4, 147.4, 145.2, 143.8, 131.9, 123.0, 120.9,
113.5, 112.1, 105.0, 100.1, 71.9, 64.4, 64.3, 58.3, 55.5 ppm; IR (neat): n˜ =
2920, 2850, 1655, 1499, 1285, 1246, 1233, 1066, 639 cmÀ1; MS (TOF ES+
5638
www.chemeurj.org
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2007, 13, 5632 – 5641

Silver Catalysts
FULL PAPER
Compound 32: This compound was prepared by method A. It was isolat-
ed as a pale oil (85%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=8.02
C
G
ACHTREUNG
4
3
3
ACHTREUNG
(d, 3J
7.68 (ddd, J
(ddd, 4J(H,H)=0.8 Hz, 3J
1H), 6.19 (s, 1H), 4.81 (q, 4J
1.1 Hz, 2J(H,H)=13.9 Hz, 1H), 4.24 (dd, 4J
N
ACHTREUNG
4
3
3
ACHTREUNG
G
G
A
N
ACHTREUNG
R
ACHTREUNG
R
E
ACHTREUNG
13.9 Hz, 1H), 3.97–3.87 (m, 1H), 3.61 (s, 3H), 1.80–1.55 (m, 5H), 1.07–
0.90 ppm (m, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=mixture of
2 diastereoisomers 157.6, 157.3, 149.6, 149.5, 149.2, 133.9, 133.8, 130.6,
129.2, 128.3, 127.5, 126.1, 122.9, 104.6, 104.2, 100.4 (”2), 98.5, 97.9, 66.2,
65.9, 62.3 (”2), 56.1, 43.9, 30.6, 30.1, 27.3, 25.8, 19.4, 19.3 ppm; TOF MS
ES+: m/z (%): 328 (100) [M+H]+; HRMS (TOF ES+): m/z calcd for
[C19H22NO4]+: 328.1549; found: 328.1548.
Compound 42: This compound was prepared by method A. It was isolat-
ed as a yellow solid (94%); 1H NMR (300 MHz, [D]CHCl3, 258C): d=
8.86 (s, 1H), 8.27 (s, 1H), 8.17 (d, 3J
ACHTREUNG
2H), 7.90 (d, 3J
A
ACHTREUNG
A
N
ACHTREUNG
AHCTREUNG
3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=153.8, 152.8, 150.0, 148.6,
137.0, 134.6, 131.7, 130.9, 129.6, 129.2, 128.6, 128.5, 127.9, 127.2, 123.4,
121.0, 106.0, 98.5, 55.8 ppm; MS (TOF ES+): m/z (%): 335 (100)
[M+H]+; HRMS (TOF ES+): m/z calcd for [C19H15N2O4]+: 335.1032;
found: 335.1049.
Compound 34: This compound was prepared by method A. It was isolat-
1
ed as a pale oil (95%). H NMR (300 MHz, [D]CHCl3, 258C): d=8.06 (s,
1H), 8.02 (d, 3J
C
G
A
(H,H)=1.1 Hz, 3J
(H,H)=6.8 Hz, J
ACHTREUNG
4
3
3
ACHTREUNG
7.69 (ddd, J
(dd, 4J(H,H)=1.5 Hz, 3J
3J
A
G
Compound 44: This compound was prepared by method A. It was isolat-
ed as a brown solid (92%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=
G
G
ACHTREUNG
N
G
ACHTREUNG
7.97 (s, 1H), 7.91 (m, 2H), 7.68 (d, 3J
ACHTREUNG
A
N
ACHTREUNG
7.14 (dd, 3J
A
ACHTREUNG
6.56 (s, 1H), 6.35 (s, 1H), 3.88 (s, 3H), 3.68 ppm (s, 3H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=168.5, 157.9, 150.4, 148.7, 134.9, 132.6,
131.4, 131.2, 130.1, 129.7, 129.6, 128.7, 128.0, 127.3, 125.7, 122.7, 105.2,
101.7, 56.5, 52.3 ppm; MS ES+: m/z (%): 348 (100) [M+H]+; HRMS
(TOF ES+): m/z calcd for [C21H18NO4]+: 348.1236; found: 348.1230.
1H), 3.97 (s, 1H), 3.70 ppm (s, 1H); 13C NMR (75 MHz, [D]CHCl3,
258C): d=161.4, 155.7, 150.6, 149.9, 133.8, 133.0, 129.8, 128.9, 125.4,
122.2, 120.3, 118.8, 106.6, 101.9, 100.2, 77.1, 55.7, 55.5 ppm; IR (neat): n˜ =
2918, 2849, 1608, 1503, 1451, 1379, 1241, 1157, 1077, 1046, 954, 907, 765,
689, 630 cmÀ1; MS ESI+: m/z (%): 320 (100) [M+H]+; HRMS (ESI+):
m/z calcd for [C20H18NO3]+: 320.1287; found: 320.1276.
Compound 35: This compound was prepared by method A. It was isolat-
ed as a pale oil (96%); 1H NMR (300 MHz, [D]CHCl3, 258C): d=8.40
Compound 46: This compound was prepared by method A. It was isolat-
ed as a dark oil (89%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=8.05
(dd, 4J
(dd, 4J(H,H)=1.5 Hz, 3J
1H), 7.78 (ddd, 4J(H,H)=1.1 Hz, 3J
1H), 7.65 (s, 1H), 7.56 (td, 4J
(H,H)=0.8 Hz, J
A
ACHTREUNG
G
ACHTREUNG
(s, 1H), 8.03 (d, 3J
(H,H)=1.3 Hz, 3J
(H,H)=7.0 Hz, 3J
(H,H)=8.5 Hz, 1H), 7.49–7.43 (m, 4H), 6.84 (s, 1H),
A
G
ACHTREUNG
A
G
A
3
ACHTREUNG
N
A
ACHTREUNG
7.28 (m, 1H), 6.66 (s, 1H), 3.99 (s, 3H), 3.61ppm (s, 3H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=168.3, 154.3, 151.8, 150.1, 135.6, 131.6,
131.4, 130.5, 130.5, 130.4, 129.8, 129.1, 128.4, 128.2, 127.7, 126.8, 126.2,
105.4, 97.9, 55.0, 52.2 ppm; MS ES+: m/z (%): 348 (100) [M+H]+;
HRMS (TOF ES+): : m/z calcd for [C21H18NO4]+: 348.1236; found:
348.1254.
3.36 (s, 3H), 1.97 ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=
155.8, 151.4, 150.6, 136.2, 132.5, 131.4, 130.8, 130.7, 130.4, 129.0, 128.4,
127.1, 126.0, 125.9, 110.8, 100.7, 51.3, 27.1 ppm; IR (neat): n˜ =2928, 2848,
1749, 1633, 1443, 1255, 1094, 749 cmÀ1; MS ESI+: m/z (%): 304 (100)
[M+H]+; HRMS (ESI+): m/z calcd for [C20H18NO2]+: 304.1338; found:
304.1341.
Compound 37: This compound was prepared by method A. It was isolat-
ed as a pale oil (89%); 1H NMR (300 MHz, [D]CHCl3, 258C): d=8.49
Compound 48: This compound was prepared by method A. It was isolat-
ed as a yellow oil (quantitative). 1H NMR (300 MHz, [D]CHCl3, 258C):
(d, 3J
3J
(H,H)=8.7 Hz, 1H), 7.71 (d, 3J
7.32 (t, 3J
U
ACHTREUNG
d=7.50–7.47 (m, 1H), 7.42–7.37 (m, 2H), 6.39 (s, 1H), 5.20 (t, 2J
(H,H)=
R
U
7.2 Hz, 1H), 4.34–4.20 (m, 2H), 3.43 (s, 3H), 3.39 ppm (s, 3H); 13C NMR
(75 MHz, [D]CHCl3, 258C): d=155.5, 138.1, 134.5, 130.2, 129.7, 123.4,
120.5, 106.9, 94.1, 66.7, 58.1, 54.7 ppm; MS (TOF ES+): m/z (%): 207
(100) [M+H]+; HRMS (TOF ES+): m/z calcd for [C12H15O3]+: 207.1021;
found: 207.1034.
N
Compound 39: This compound was prepared by method A. It was isolat-
ed as a yellow solid (94%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=
Compound 49: This compound was prepared by method A. It was isolat-
ed as a yellow oil (quantitative). 1H NMR (300 MHz, [D]CHCl3, 258C):
8.07 (d, 3J
3J
7.69 (ddd, J
(ddd, 4J(H,H)=1.1 Hz, 3J
1H), 7.38 (ddd, 4J(H,H)=1.5 Hz, 3J
1H), 7.06 (dd, 4J(H,H)=1.5 Hz, 3J(H,H)=7.5 Hz, 1H), 7.01 (app. d, 3J-
(H,H)=7.9 Hz, 1H), 6.31 (s, 1H), 3.97 (s, 3H), 3.68 ppm (s, 3H);
A
ACHTREUNG
d=7.32 (qd, 4J
7.12 (d, 3J
A
ACHTREUNG
(H,H)=7.9 Hz, 1H), 7.79 (dd, 4J
3
ACHTREUNG
AHCTREUNG
A
N
A
N
ACHTREUNG
further characterization was consistent with published data.[6a]
A
N
ACHTREUNG
Compound 51: This compound was prepared by method A. It was isolat-
ed as a brown oil (96%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=7.85
A
ACHTREUNG
ACHTREUNG
(d, 3J
(H,H)=6.9 Hz, 1H), 7.44–7.36 (m, 5H), 7.25–7.30 (m, 3H), 6.64 (s,
R
13C NMR (75 MHz, [D]CHCl3, 258C): d=158.1, 150.3, 133.1, 130.7, 130.2,
128.5, 128.3, 127.9, 127.1, 125.5, 122.8, 120.4, 111.3, 107.3, 99.9, 55.9,
55.5 ppm; IR (neat): n˜ =2919, 2850, 2325, 1713, 1614, 1490, 1428, 1243,
1170, 1122, 1009, 954, 900, 810, 610 cmÀ1; MS (TOF ES+): m/z (%): 320
(100) [M+H]+; HRMS (TOF ES+): m/z calcd for [C20H18NO3]+:
320.1287; found: 320.1291.
1H), 6.18 (s, 1H), 3.64 ppm (s, 3H); MS (TOF ES +): m/z (%): 239 (100)
[M+H]+; HRMS (ESI+): m/z calcd for [C16H15O2]+: 239.1072; found:
239.1059. further characterization was consistent with published data.[5a]
Compound 52: This compound was prepared by method A. It was isolat-
1
ed as a brown oil (96%); H NMR (300 MHz, [D]CHCl3, 258C): d=7.77
(d, 3J
A
G
N
Compound 41: This compound was prepared by method A. It was isolat-
ed as a yellow solid (94%). 1H NMR (300 MHz, [D]CHCl3, 258C): d=
1H), 7.48–7.33 (m, 5H), 7.22–7.16 (m, 1H), 6.57 (s, 1H), 6.00 (s, 1H),
3.51ppm (s, 3H); 13C NMR (75 MHz, [D]CHCl3, 258C): d=171.1, 135.8,
135.5, 129.9, 128.9, 128.4, 128.3, 125.9, 123.1, 119.8, 107.4, 98.2, 60.3 ppm;
MS (TOF ES+): m/z (%): 239 (100) [M+H]+; HRMS (ESI+): m/z
calcd for [C16H15O2]+: 239.1072; found: 239.1086.
8.76 (t, 4J
2.3 Hz, 3J
7.9 Hz, 1H), 8.10 (s, 1H), 8.08 (d, 3J
(H,H)=1.1 Hz, 3J(H,H)=8.3 Hz, 1H), 7.75 (ddd, 4J
C
G
ACHTREUNG
U
ACHTREUNG
N
ACHTREUNG
Chem. Eur. J. 2007, 13, 5632 – 5641ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5639

P. Belmont et al.
2004, 104, 3079; for alcohols and phenols see: e) S. Antoniotti, E.
Genin, V. Michelet, J.-P. GenÞt, J. Am. Chem. Soc. 2005, 127, 9976;
f) B. M. Trost.; Y. H. Rhee, J. Am. Chem. Soc. 2003, 125, 7482; g) B.
Gabriele, G. Salerno, A. Fazio, R. Pittelli, Tetrahedron 2003, 59,
6251; h) A. S. Droz, U. Neidlein, S. Anderson, P. Seiler, F. Diederich,
Helv. Chim. Acta 2001, 84, 2243; i) K. Hiroya, R. Jouka, M.
Kameda, A. Yasuhara, T. Sakamoto, Tetrahedron 2001, 57, 9697;
j) F. E. McDonald, Chem. Eur. J. 1999, 5, 3103; k) J. H. Teles, S.
Brode, M. Chabanas, Angew. Chem. 1998, 110, 1475; Angew. Chem.
Int. Ed. 1998, 37, 1415; l) M. D. Weingarten, A. Padwa, Tetrahedron
Lett. 1995, 36, 4717; m) D. Villemin, D. Goussu, Heterocycles 1989,
29, 1255; for acids see: n) V. Subramanian, V. R. Batchu, D. Bar-
ange, M. Pal, J. Org. Chem. 2005, 70, 4778; o) G. Balme, D. Bouyssi,
T. Lomberget, N. Monteiro, Synthesis 2003, 2115; p) F. Bellina, D.
Ciucci, P. Vergamini, R. Rossi, Tetrahedron 2000, 56, 2533; q) Y.
Ogawa, M. Maruno, T. Wakamatsu, Heterocycles 1995, 41, 2587.
[9] For recent reviews, see: a) an extensive review on gold chemistry:
A. S. K. Hashmi, G. J. Hutchings, Angew. Chem. 2006, 118, 8064;
Angew. Chem. Int. Ed. 2006, 45, 7896; b) A. S. K. Hashmi, Angew.
Chem. 2005, 117, 7150; Angew. Chem. Int. Ed. 2005, 44, 6990;
c) A. S. K. Hashmi, Hung. Build. Bull. Gold. Bull. 2004, 37, 51 ; d) G.
Dyker, Angew. Chem. 2000, 112, 4407; Angew. Chem. Int. Ed. 2000,
39, 4237.
Acknowledgements
P.B. thanks the Centre National de la Recherche Scientifique (CNRS),
the Minist›re de lꢁEducation Nationale et de la Recherche (Fellowships
for T.G. and C.M.) and the Association pour la Recherche sur le Cancer
(ARC) for financial support. We also thank N. Henriques, L. Rousset-
Arzel, Dr. D. Bouchu, and Dr. G. Dessalces for the mass spectrometry
data.
[1] J. P. Michael, Nat. Prod. Rep. 2005, 22, 627; J. P. Michael, Nat. Prod.
Rep. 2004, 21, 650; J. P. Michael, Nat. Prod. Rep. 2003, 20, 476; J. P.
Michael, Nat. Prod. Rep. 2002, 19, 742.
[2] T. Godet, J. Bosson, P. Belmont, Synlett 2005, 2786.
[3] a) J. Barluenga, H. Vµsquez-Villa, I. Merino, A. Ballesteros, J. M.
Gonzµlez, Chem. Eur. J. 2006, 12, 5790; b) J. Barluenga, H.
Vµsquez-Villa, A. Ballesteros, J. M. Gonzal›z, J. Am. Chem. Soc.
2003, 125, 9028.
[4] D. Yue, N. D. Cà, R. C. Larock, Org. Lett. 2004, 6, 1581.
[5] a) L.-L. Wei, L.-M. Wei, W.-B. Pan, M.-J. Wu, Synlett 2004, 1497;
b) S. Mondal, T. Nogami, N. Asao, Y. Yamamoto, J. Org. Chem.
2003, 68, 9496; c) M. Guliàs, J. R. Rodrìguez, L. Castedo, J. L. Mas-
careÇas, Org. Lett. 2003, 5, 1975; d) N. Asao, T. Nogami, K. Takaha-
shi, Y. Yamamoto, J. Am. Chem. Soc. 2002, 124, 764.
[10] a) On related substrates AuIII-catalyzed reactions of aldehydes on al-
kynes led only to benzannulation; see references [7a,g,w,z];
b) review: N. Asao, Synlett 2006, 1645.
[6] a) N. T. Patil, Y. Yamamoto, J. Org. Chem. 2004, 69, 5139; b) N.
Asao, C. S. Chan, K. Takahashi, Y. Yamamoto, Tetrahedron 2005,
61, 11322.
[11] a) X. Yao, C.-J. Li, Org. Lett. 2006, 8, 1953; b) a AuCl3-catalyzed
furan synthesis by a tandem 1,4-addition of oxygenated species fol-
lowed by addition of carbonyl onto alkynes: T. Yao, X. Zhang, R. C.
Larock, J. Am. Chem. Soc. 2004, 126, 11164; c) a AuCl3-catalyzed
furanone synthesis from 2-oxo-butanoates: Y. Liu, M. Liu, S. Guo,
H. Tu, Y. Zhou, H. Gao, Org. Lett. 2006, 8, 3445.
[7] a) A. B. Beeler, S. Su, C. A. Singleton, J. A. Porco Jr., J. Am. Chem.
Soc. 2007, 129, 1413; b) C. Ferrer, C. H. M. Amijs, A. M. Echavar-
ren, Chem. Eur. J. 2007, 13, 1358; c) R. Skouta, C.-J. Li, Angew.
Chem. 2007, 119, 1135; Angew. Chem. Int. Ed. 2007, 46, 1 1 1 7;
d) A. K. Buzas, F. M. Istrate, F. Gagosz, Angew. Chem. 2007, 119,
1159; Angew. Chem. Int. Ed. 2007, 46, 1141; e) T. J. Harrison, J. A.
Kozak, M. Corbella-PanØ, G. R. Dake, J. Org. Chem. 2006, 71, 4525;
f) C. Ferrer, A. M. Echavarren, Angew. Chem. 2006, 118, 1123;
Angew. Chem. Int. Ed. 2006, 45, 1105; g) N. Asao, H. Aikama, J.
Org. Chem. 2006, 71, 5249; h) D. Hildebrandt, G. Dyker, J. Org.
Chem. 2006, 71, 6728; i) I. V. Seregin, V. Gevorgyan, J. Am. Chem.
Soc. 2006, 128, 12050; j) R. Robles-Machín, J. Adrio, J. C. Carretero,
J. Org. Chem. 2006, 71, 5023; k) S. I. Lee, S. M. Kim, M. R. Choi,
S. Y. Kim, Y. K. Chung, J. Org. Chem. 2006, 71, 9366; l) G. Lemi›re,
V. Gandon, N. Agenet, J.-P. Goddard, A. de Kozak, C. Aubert, L.
Fensterbank, M. Malacria, Angew. Chem. 2006, 118, 7758; Angew.
Chem. Int. Ed. 2006, 45, 7596; m) S. Couty, C. Meyer, J. Cossy,
Angew. Chem. 2006, 118, 3878; Angew. Chem. Int. Ed. 2006, 45,
6726; n) E. Gelin, P. Y. Toullec, S. Antoniotti, C. Brancour, J.-P.
GenÞt, V. Michelet, J. Am. Chem. Soc. 2006, 128, 3112; o) N.
Marion, S. Díez-Gonzµlez, P. de FrØmont, A. R. Noble, S. P. Nolan,
Angew. Chem. 2006, 118, 3729; Angew. Chem. Int. Ed. 2006, 45,
3647; p) M. H. Suhre, M. Reif, S. F. Kirsch, Org. Lett. 2005, 7, 3925;
q) X. Shi, D. J. Gorin, F. D. Toste, J. Am. Chem. Soc. 2005, 127,
5802; r) L. Zhang, S. A. Kozmin, J. Am. Chem. Soc. 2005, 127, 6962;
s) M. Alfonsi, A. Arcadi, M. Aschi, G. Bianchi, F. Marinelli, J. Org.
Chem. 2005, 70, 2265; t) S. T. Staben, J. J. Kennedy-Smith, F. D.
Toste, Angew. Chem. 2004, 116, 5464; Angew. Chem. Int. Ed. 2004,
43, 5350; u) J. J. Kennedy-Smith, S. T. Staben, F. D. Toste, J. Am.
Chem. Soc. 2004, 126, 4526; v) V. Mamane, T. Gress, H. Krause, A.
Fꢂrstner, J. Am. Chem. Soc. 2004, 126, 8654; w) N. Asao, H.
Aikama, Y. Yamamoto, J. Am. Chem. Soc. 2004, 126, 7458; x) G.
Dyker, D. Hildebrandt, J. Liu, K. Merz, Angew. Chem. 2003, 115,
4536; Angew. Chem. Int. Ed. 2003, 42, 4399; y) C. Nevado, D. J.
Cµrdenas, A. Echavarren, Chem. Eur. J. 2003, 9, 2627; z) N. Asao,
K. Takahashi, S. Lee, T. Kasahara, Y. Yamamoto, J. Am. Chem. Soc.
2002, 124, 12650.
1
[12] a) Simple H NMR analysis allows us to discriminate the 5-exo from
the 6-endo product, since the ethylenic proton in compound 2 (ob-
tained by base-catalyzed cyclization[2] or with silver salts from en-
tries 9–11 in Table 2) has a 3J coupling constant with the CH2-OMe,
which is not present in the 6-endo-product 3 (4J instead). Also NOe
experiments on compound 2 proved that the 5-exo-dig product
formed is the Z isomer. All these data helped in the correct struc-
ture assignation. b) For the synthesis see the Experimental Section.
[13] a) J. Sun, S. A. Kozmin, Angew. Chem. 2006, 118, 51 1 3A; ngew.
Chem. Int. Ed. 2006, 45, 4991; b) Reference [7e]; c) X. Yao, C.-J. Li,
Org. Lett. 2005, 7, 4395; d) J. U. Rhee, M. J. Krische, Org. Lett. 2005,
7, 2493; e) N. Asao, S. Yudha S. , T. Nogami, Y. Yamamoto, Angew.
Chem. 2005, 117, 5662; Angew. Chem. Int. Ed. 2005, 44, 5526; f) T. J.
Harrison, G. R. Dake, Org. Lett. 2004, 6, 5023; g) Z. Li, C. Wei, L.
Chen, R. S. Varma, C.-J. Li, Tetrahedron Lett. 2004, 45, 2443; h) C.
Wei, Z. Li, C.-J. Li, Org. Lett. 2003, 5, 4473; i) a review with some
À
C O examples: Z. Li, C. He, Eur. J. Org. Chem. 2006, 19, 4313;
j) an example with alcohol: P. Pale, J. Chuche, Eur. J. Org. Chem.
2000, 1019; k) in reference [7a] the oxygenated intermediate dimer-
ized.
[14] N. T. Patil, N. K. Pahadi, Y. Yamamoto, J. Org. Chem. 2005, 70,
10096.
[8] For general reviews on transition-metal-catalyzed addition of het-
eroatom on alkynes, see following reference [9] and a) L. Chen, C.-J.
[15] a) T.-T. Jong, S.-J. Leu, J. Chem. Soc. Perkin Trans. 1 1990, 423;
b) G. S. Lewandos, D. K. Gregston, F. R. Nelson, J. Organomet.
Chem. 1976, 118, 363.
Li, Adv. Synth. Catal. 2006, 348, 1459; b) I. Nakamura, Y. Yamamo-
to, Chem. Rev. 2004, 104, 2127; c) G. Zeni, R. C. Larock, Chem. Rev.
2004, 104, 2285; d) F. Alonso, I. P. Beletskaya, M. Yus, Chem. Rev.
5640
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ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2007, 13, 5632 – 5641

Silver Catalysts
FULL PAPER
[16] X. Yao, C.-J. Li, J. Org. Chem. 2005, 70, 5752, and references there-
in.
[17] M. FØtizon, K. A. Parker, D.-S. Su in Handbook of Reagents for Or-
ganic Synthesis, Oxidizing and Reducing Agents (Eds.: L. A. Pa-
quette, S. D. Burke, R. L. Danheiser), Wiley, New York, 1999.
pp. 361–366 and pp. 368–372.
[18] a) M. B. Smith, J. March in Marchꢀs Advanced Organic Chemistry:
Reactions, Mechanisms, and Structure, 5th ed. Wiley, New York,
2001. pp. 329–331and p. 343; b) For HOCN (AgOCN) see S. Buda-
vari in The Merck Index, 12th ed. (Ed.: S. Budavari), Merck, White-
house Station, NJ, 1996, p. 452, no. 2756.
[19] In addition, control cyclization experiments with KOTf and HNTf2
gave no results.
[20] The product ratio 5-exo/6-endo depends greatly on the nature of the
carbonyl group,[3b,4] of the alkyne substituent,[7n,15a] and of the na-
ture,[5c,8d] or oxidative state[6a] of the activating agent.
[21] A. D. Becke, J. Chem. Phys. 1993, 98, 5648: we used a lanl2dz
pseudo potential and the corresponding basis set for Ag atom.
[22] Gaussian 03, Revision B.04, M. J. Frisch, G. W. Trucks, H. B. Schle-
gel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, J. A. Montgomer-
y, Jr., T. Vreven, K. N. Kudin, J. C. Burant, J. M. Millam, S. S. Iyen-
gar, J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N.
Rega, G. A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K.
Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda,
O. Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P. Hratchian,
J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E.
Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J. W.
Ochterski, P. Y. Ayala, K. Morokuma, G. A. Voth, P. Salvador, J. J.
Dannenberg, V. G. Zakrzewski, S. Dapprich, A. D. Daniels, M. C.
Strain, O. Farkas, D. K. Malick, A. D. Rabuck, K. Raghavachari,
J. B. Foresman, J. V. Ortiz, Q. Cui, A. G. Baboul, S. Clifford, J. Cio-
slowski, B. B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaro-
mi, R. L. Martin, D. J. Fox, T. Keith, M. A. Al-Laham, C. Y. Peng,
A. Nanayakkara, M. Challacombe, P. M. W. Gill, B. Johnson, W.
Chen, M. W. Wong, C. Gonzalez, J. A. Pople, Gaussian, Inc., Wall-
ingford CT, 2004; see also the Supporting Information.
[23] a) O. Meth-Cohn, B. Narine, B. Tarnowski, J. Chem. Soc. Perkin
Trans. 1 1981, 1531; b) M. Toyota, C. Komori, M Ihara, J. Org.
Chem. 2000, 65, 7110; c) P. Belmont, T. Belhadj, Org. Lett. 2005, 7,
1793; d) A. Patin, P. Belmont, Synthesis 2005, 2400.
Received: February 4, 2007
Published online: March 16, 2007
Chem. Eur. J. 2007, 13, 5632 – 5641ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5641