Diastereoselective synthesis of three-, five-, six-, and seven-membered rings from fischer carbene complexes and 4-unsubstituted 1-amino-1,3-dienes

Article abstract of DOI:10.1002/chem.200701109

Fischer carbene complexes react with 4-unsubstituted 1-amino-1,3-dienes to give different carbocyclization products depending on the nature of the carbene complex and on the substitution pattern of the aminodiene. Thus, the reaction of arylcarbene chromium complexes and 1-aminodienes diastereoselectively affords cyclopropane derivatives by means of a formal [2+1] carbocyclization reaction. In particular, pentacarbonyl[(2-furyl)-(methoxy)methylene]chromium complex furnishes formal [4+1] carbocycli-zation products. Starting from β-substituted alkenylcarbene complexes, formal [4+1] reactions occur and cyclopentenamine derivatives are diastereoselectively formed. However, when the α,β-disubstituted alkenylcarbene complex pentacarbonyl[(5,6-dihydro- 2H-pyran-2-yl)(methoxy)methylene]-tungsten is used, the outcome of the reaction depends on the substitution on the carbon atom at the 3-position of the aminodiene, generating the [3+2] or [4+3]-cyclization products if the substituent is or is not a hydrogen atom, respectively. Finally, when the reaction is performed with alkynylcarbene complexes, benzaldehyde derivatives are obtained if the triple-bond substituent is a phenyl group or indene derivatives if the group is an alkenyl moiety.

Full text of DOI:10.1002/chem.200701109

FULL PAPER
DOI: 10.1002/chem.200701109
Diastereoselective Synthesis of Three-, Five-, Six-, and Seven-Membered
Rings from Fischer Carbene Complexes and 4-Unsubstituted
1-Amino-1,3-Dienes
Fernando Aznar,* Martín FaÇanµs-Mastral, Jorge Alonso, and Francisco J. FaÇanµs*[a]
Abstract: Fischer carbene complexes
react with 4-unsubstituted 1-amino-1,3-
dienes to give different carbocycliza-
tion products depending on the nature
of the carbene complex and on the sub-
stitution pattern of the aminodiene.
Thus, the reaction of arylcarbene chro-
mium complexes and 1-aminodienes
diastereoselectively affords cyclopro-
pane derivatives by means of a formal
[2+1] carbocyclization reaction. In par-
zation products. Starting from b-substi-
tuted alkenylcarbene complexes,
formal [4+1] reactions occur and cyclo-
pentenamine derivatives are diastereo-
selectively formed. However, when the
a,b-disubstituted alkenylcarbene com-
tungsten is used, the outcome of the re-
action depends on the substitution on
the carbon atom at the 3-position of
the aminodiene, generating the [3+2]
or [4+3]-cyclization products if the
substituent is or is not a hydrogen
atom, respectively. Finally, when the re-
action is performed with alkynylcar-
bene complexes, benzaldehyde deriva-
tives are obtained if the triple-bond
substituent is a phenyl group or indene
derivatives if the group is an alkenyl
moiety.
plex
pentacarbonyl[(5,6-dihydro-2H-
pyran-2-yl)(methoxy)methylene]-
Keywords: aminodienes · carbenes ·
cyclization · diastereoselectivity ·
organic synthesis
ticular,
pentacarbonyl
A
ACHTREUNG
plex furnishes formal [4+1] carbocycli-
Introduction
aminodienes has resulted to be an interesting entry for the
preparation of five-, six-, and seven-membered carbo- and
heterocycles. Thus, reactions of aryl and alkenylcarbene
complexes with 1,3-diamino-1,3-dienes leads to the forma-
tion of formal [4+1] cyclopentenones.[6] Nevertheless, 1-
amino-1-aza-1,3-dienes and chromium alkenylcarbene com-
plexes also undergo cyclopentannulation to furnish [3+2]-
substituted cyclopentenes in a regio and disatereoselective
way along with minor amounts of [4+1] pyrrole deriva-
tives.[7] While 2-amino-1,3-butadienes react with Group 6 ar-
ylcarbene complexes giving the metathesis products,[8] a,b-
unsaturated boroxy-[9] and methoxycarbene[10] complexes
lead to the corresponding [4+2] cycloaddition products. In-
terestingly, the use of b-substituted methoxy alkenyl chromi-
um carbenes instead of the corresponding tungsten deriva-
tives produces a substantial change on the reaction outcome
and the formal [4+3] cycloheptadienone derivatives are ob-
tained.[6,11] [4+3] Heterocyclizations have been successfully
effected by starting from 4-amino-1-aza-1,3-dienes and unsa-
turated carbene complexes.[12] Imines derived from pyrrole-
and indolecarbaldehydes, which can be considered as 3-
amino-1-aza-1,3-diene derivatives, react with unsaturated
carbene complexes giving rise to the formal [3+3 ] or
[4+3][13] cycloadducts depending on the substitution pattern
The search for new methodologies for the selective synthesis
of small- and medium-sized carbocycles continues to be of
great interest for organic chemists[1] due to the presence of
these skeletons in biologically relevant compounds.[2] Organ-
ometallic compounds have considerably contributed to the
development of important processes for the construction of
cyclic products with different ring sizes.[3] In this context,
Fischer carbene complexes have proved to be very efficient
and extraordinarily versatile starting materials for carrying
out a wide range of cycloaddition reactions, which provide a
great array of carbocyclic and heterocyclic ring systems with
a high degree of selectivity in most cases.[4,5] In particular,
the reaction of stabilized Group 6 carbene complexes and
[a] Prof. Dr. F. Aznar, M. FaÇanµs-Mastral, Dr. J. Alonso,
Prof. Dr. F. J. FaÇanµs
Instituto Universitario de Química Organometµlica
“Enrique Moles”, Unidad Asociada al CSIC
Universidad de Oviedo, Juliµn Clavería 8
33006 Oviedo (Spain)
Fax : (+34)985-103-450
E-mail: fag@uniovi.es
fjfv@uniovi.es
Chem. Eur. J. 2008, 14, 325 – 332
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325

Table 1. Cyclopropane derivatives 3 and cyclopentenamines 4 from aryl-
carbene complexes 1 and 1-aminodienes 2.
of the heterocyclic nitrogen. Finally, 2-amino-1,3-butadienes
can also participate in reactions with alkynylcarbene com-
plexes. Particularly when aryl- and alkenylalkynylcarbene
complexes were used, mono, double, or triple [4+2] cycload-
dition–cyclopentannulation tandem reactions were ob-
served.[14] Considering that 1-aminodienes have been scarce-
ly used in these types of transformations, we present herein
the reaction of Group 6 carbene complexes and 4-unsubsti-
tuted 1-amino-1,3-butadienes to afford three-, five-, six-, and
seven-membered carbocyclic rings in a diastereoselective
way. Formal [2+1], [3+2], [4+2], and [4+3] cyclization reac-
tions are observed and the reaction outcome depends on the
nature of the substituents of both the 1-aminodiene and the
carbene complex, and also on the metal of the carbene com-
plex.
Carbene Ar
complex
Aminodiene R1
R2
Product Yield [%][a]
1a
1a
1a
1b
1c
1c
Ph
Ph
Ph
2a
2b
2c
H
H
Me
H
H
H
3a
62
70
73
52
62
60
Me 3b
H
H
Me 4a
H 4b
3c
3d
1-Naph[b] 2a
2-Fu[c]
2-Fu[c]
2b
2c
Me
[a] Isolated yield based on starting carbene complexes 1. [b] 1-Naphthyl.
[c] 2-Furyl.
conditions does not proceed and it is necessary to warm to
508C for complete consumption of the starting carbene
complex. Under these new reaction conditions, the formal
[4+1] cyclopentenamine derivatives 4, in which the amino-
diene has acted as a four-unit component and the carbene
complex as a one-unit component, are isolated (Scheme 1
and Table 1). Also remarkable is that all these reactions did
not proceed when using the corresponding tungsten carbene
complexes.
Results and Discussion
Taking into account that the results of the reaction of car-
bene complexes and 4-unsubstituted 1-aminodienes are
highly dependent on the nature of the substituent of the car-
bene complex used, the results and discussion have been
systematized according to the structure of these starting
complexes.
Alkenylcarbene complexes. Formal [4+1], [3+2], and [4+3]
cyclization reactions: Next, we decided to investigate the be-
havior of alkenylcarbene complexes towards aminodienes 2.
Initially, we began the study with b-substituted alkenylcar-
bene complexes 5. Therefore, reaction of aminodienes 2
with alkenylcarbene tungsten complexes 5 in diethyl ether
or THF at temperatures ranging between 0 and 208C gave
rise, after hydrolysis with silica gel, to cyclopentenamine de-
rivatives 6 in good yields and with high diastereoselectivity
(Scheme 2 and Table 2). This transformation can be consid-
Aryl carbene complexes. Formal [2+1] cyclizations: When
arylcarbene chromium complexes 1 were treated with one
equivalent of 1-aminodienes 2 in THF at temperatures rang-
ing between 0 and 208C, cyclopropane derivatives 3 were
obtained, after hydrolysis with silica gel, in moderate yield
and as single diastereoisomers (Scheme 1 and Table 1).
Scheme 2. Reaction of b-substituted alkenylcarbene complexes 5 and
aminodienes 2 to give cyclopentenamine derivatives 6.
Table 2. Cyclopentenamine derivatives 6 from alkenylcarbene complexes
5 and aminodienes 2.
Entry Carbene Ar
complex
Amino R1 R2 Solvent Product Yield
diene
Scheme 1. Reaction of arylcarbene complexes 1 and 4-unsubstituted 1,3-
aminodienes 2 to give cyclopropane derivatives 3 and cyclopentenamines
4.
[%][a]
(de [%])[b]
ACHTREUNG
1
2
3
4
5
6
7
8
5a
5a
5a
5a
5b
5b
5a
5b
Ph
Ph
Ph
Ph
2a
2a
2b
2b
H
H
H
H
H
H
Me
Me
H
H
Et2O
THF
6a
6a
6b
6b
6c
6c
6d
6e
78 (65)
81 (87)
81 (68)
89 (90)
86 (60)[d]
80 (80)[d]
73( >95)
71 (80)
Compounds 3 can be considered as a result of a formal
[2+1] carbocyclization reaction, in which the aminodiene
acts as synthon of two carbon units and the carbene com-
plex as a synthon of one carbon unit. The structure and rela-
tive configuration of the stereogenic centers of compounds
3a–e were determined by 2D NMR spectroscopic analysis
(COSY, HMQC, HMBC, and NOESY).
Me Et2O
Me THF
Me Et2O
Me THF
H
H
Fu[c] 2b
Fu[c] 2b
Ph
2c
THF
THF
Fu[c] 2c
[a] Isolated yield based on starting carbene complexes 5. [b] The diaste-
reoisomeric excess was determined by 1H NMR spectroscopy on the re-
action crude. [c] 2-Furyl. [d] Compound 6c and diast-6c can be separated
by column chromatography.
It is interesting to note that the reaction of furylcarbene
complex 1d with aminodienes 2 under the same reaction
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Chem. Eur. J. 2008, 14, 325 – 332

Three-, Five-, Six-, and Seven-Membered Rings
FULL PAPER
ered as a formal [4+1] cyclization reaction. The structure
and configuration of the stereogenic centers formed were
determined by 2D NMR spectroscopic analysis (COSY,
HMQC, HMBC, and NOESY) carried out on 6d.
of the ring system and it was ascertained by the coupling
constants and selective NOE experiments. The quartet of
doublets signal for H5ax (d=0.92 ppm, J=12.9, 3.6 Hz) fixes
an axial disposition for the H6 proton. The cross peaks on
the resolved J 2D spectrum allow the assignation of H8 pro-
tons and fix an axial disposition for the H7 proton as a con-
sequence of the triplet signal for H8ax (d=1.93ppm, J=
12.1 Hz). Moreover, the selective NOE experiments place
H11 and H5eq protons on the same face of the molecule and
confirm the axial disposition of H6 and H7 protons. Con-
versely, when the carbene complex 7 was reacted with the 3-
substituted aminodiene 2c under the same reaction condi-
tions, a different reaction outcome was observed and the
formal [4+3] cyclization cyclohepta[b]pyranamine derivative
9 (four carbon units come from the aminodiene and three
from the carbene complex) was formed in 69% yield as a
unique diastereoisomer, as deduced from the 2D NMR spec-
troscopic analysis (Scheme 3).
From the results summarized in Table 2, it can be inferred
that a more polar solvent, THF versus Et2O, increases the
diastereoselectivity of the reaction (Table 2, entries 1–6).
The presence of a heteroatom in the aryl substituent of the
carbene complex produces a slight decrease in the diastereo-
selectivity (Table 2, entries 4, 6, 7, and 8). The substitution
pattern of the aminodiene also influences on the diastereo-
selectivity. So, substitution at the 3-position of the amino-
diene leads to better diastereoselectivities (Table 2, entry 7).
A different reaction outcome was observed when a,b-di-
substituted alkenyl–tungsten carbene complex 7 was used.[15]
Thus, treatment of carbene complex 7 with aminodienes
2a,b under the same reaction conditions as above described
led, after hydrolysis, to cyclopenta[b]pyrane derivatives 8 in
good yields (Scheme 3). These compounds could be consid-
Alkynylcarbene complexes. Formal [4+2] cyclization and
cascade reactions: Considering the influence of the nature
of the group bound to the carbene carbon of the carbene
complex, we decided to further study the behavior of alky-
nylcarbene complexes in this chemistry. Initially, arylalky-
nylcarbene complex 10a was treated with aminodienes 2 in
THF at temperatures ranging between À50 and 08C leading,
after hydrolysis, to the corresponding benzaldehyde deriva-
tives 11 in good yields. However, a different result was ach-
ieved when starting from alkenylalkynylcarbene complexes
10b,c which reacted with aminodienes 2 under the same re-
action conditions to afford indene derivatives 12 in moder-
ate to good yields (Scheme 4 and Table 3).
Scheme 3. Reaction of a,b-substituted alkenylcarbene complex 7 and
aminodienes 2 to give cyclopenta[b]pyrane and cyclohepta[b]pyranamine
derivatives 8 and 9.
ered formal [3+2] cyclization products, in which the carbene
complex has acted as a synthon of three carbon units and
the aminodiene as a synthon of two carbon units. Although
compound 8b was obtained as a mixture of two diastereo-
isomers, it is interesting to remark that the cyclization reac-
tion is a completely diastereoselective process and the ob-
served diastereoselectivity comes from the formation of two
epimers at the a-position of the aldehyde. Attempts to equi-
librate this mixture to give a single diastereoisomer by treat-
ment with catalytic amounts of acid or base were unsuccess-
ful.
The structure of compounds 8 was unequivocally deter-
mined by 2D NMR experiments (COSY, HMQC, and
HMBC) carried out on compound 8a. The same chemical
shift for H6 and H7 protons did not allow us to clearly de-
termine the relative configuration of the stereogenic centers
Scheme 4. Reaction of carbene complexes 10 and aminodienes 2 to give
benzaldehydes 11 and indene derivatives 12.
Mechanistic proposals: Tentative mechanisms to rationalize
the formation of the different products obtained in the reac-
tion of carbene complexes 1, 5, 7, and 10 and aminodienes 2
are presented. We assume in the first place that a 1,2-addi-
tion of the distal carbon atom of the aminodiene 2 to the
carbene complexes 1, 5, and 7 occurs to form intermediates
13, 14, or 15. The evolution of these intermediates depends
on the nature of the R group of the carbene complex. Thus,
when R is an aryl group, a Michael addition of the carbon
Chem. Eur. J. 2008, 14, 325 – 332
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327

F. J. FaÇanµs, F. Aznar et al.
Table 3. Benzaldehydes 11 and indene derivatives 12 from alkynylcar-
bene complexes 10 and 1-aminodienes 2.
Carbene R3
complex
Aminodiene R1 R2 Product Yield
[%][a]
10a
10a
10a
10b
10c
Ph
Ph
Ph
2a
2b
2c
H
H
Me
H
H
H
11a
Me 11b
11c
Me 12a
12b
66
70
72
61
55
H
R4-R5 =(CH2)4 2b
R4 =H,
R5 =Ph
2a
H
Scheme 6. Mechanistic proposal for the formation of cyclopentenamine
derivatives 6.
[a] Isolated yield based on starting carbene complexes 10.
tributed to transition states with the same geometric disposi-
tion as those shown in intermediates 14 and 14’, respectively.
Thus, the immonium and alkenyl moieties would be placed
in a pseudoequatorial disposition on a chairlike transition
state. A similar mechanism could account for the formation
of compounds 4.
atom attached to the pentacarbonylmetalate to the unsatu-
rated immonium moiety in intermediates 13 would lead to
the cyclic systems 16, which after hydrolysis, would give rise
to the cyclopropane derivatives 3. Formation of products 4
could be accounted for considering a nucleophilic attack of
the carbon atom of the allylpentacarbonylmetallate to the
immonium group in intermediates 13. Moreover, the com-
plete diastereoselectivity found in the formation of com-
pounds 3 could be attributed to transition states with the
same geometric disposition as intermediates 13, probably fa-
vored by an electrostatic interaction between the negatively
charged pentacarbonylmetal fragment and the positively
charged immonium group. Consequently, the smaller me-
thoxy group would be positioned on the side of the R1 and
R2 groups (Scheme 5).
On the other hand, a,b-disubstituted alkenylcarbene com-
plexes follow a different reaction pattern.[15] Moreover, the
evolution of intermediates 15 is also different depending on
the nature of the R2 group. Thus, when the R2 group is a hy-
drogen atom, intermediate 15 could undergo an intramolec-
ular Michael addition of the allyltungstate to the unsaturat-
ed immonium moiety, presumably induced by a 1,2-migra-
tion[17] of the pentacarbonyltungsten fragment, affording the
five-membered intermediate 17. Further elimination of the
metal moiety would furnish, after hydrolysis and metal de-
coordination, the cyclopentapyrane derivatives 8. On the
contrary, when the R2 group is a methyl group, the Michael
addition would as a result be disfavored by steric hindrance
of the methyl group. In these circumstances, a nucleophilic
attack to the immonium carbon atom would be preferred
and the seven-membered intermediate 18 would be formed.
Elimination of the metal fragment would furnish the cyclo-
heptapyrane derivative 9 (Scheme 7).
Scheme 5. Mechanistic proposal for the formation of cyclopropane deriv-
atives 3.
The evolution of intermediates 14, bearing an alkenyl
group, depends on the substitution pattern of the double
bond. Thus for b-substituted alkenyl groups, we could con-
sider that intermediate 14 could be in equilibrium with 14’,
derived from an 1,3-migration[16] of the pentacarbonylmetal.
A nucleophilic attack of the g-carbon atom of the allylpen-
tacarbonylmetallate to the carbon atom of the immonium
moiety in intermediates 14’ would lead to the cyclopentena-
mines 6, after hydrolysis and metal decoordination. Alterna-
tively, compounds 6 could be formed by an attack of the a-
carbon atom of the allylmetallate moiety of intermediate 14
to the immonium group (Scheme 6). The high diastereose-
lectivity found in the formation of compounds 6 could be at-
Scheme 7. Mechanistic proposal for the formation of cyclopentapyrane
and cycloheptapyrane derivatives 8 and 9.
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Chem. Eur. J. 2008, 14, 325 – 332

Three-, Five-, Six-, and Seven-Membered Rings
FULL PAPER
The complete diastereoselectivity found in the formation
of compounds 8 and 9 could be attributed to transition
states with the same geometric disposition as intermediates
15 (R2 =H or R2 =Me), in which the unsaturated immonium
or the immonium moiety, respectively, would be placed in a
pseudoequatorial disposition on the chairlike transition
state, thus avoiding the interaction with the sterically de-
manding methylene group of the dihydropyranyl moiety.
Finally, in Scheme 8, a tentative proposal to account for
the formation of products 11 and 12 is presented. We first
consider a formal [4+2] cycloaddition reaction, probably by
highly depends on the structure of the carbene complex.
Thus, starting from arylcarbene chromium complexes, cyclo-
propane derivatives derived from a formal [2+1] carbocycli-
zation reaction are diastereoselectively obtained. Only for
the furylcarbene complex, a formal [4+1] carbocyclization
reaction was observed. In the case of b-substituted alkenyl-
carbene complexes, formation of five-membered rings by
formal [4+1] carbocyclization reactions occurs. Conversely,
a,b-disubstituted alkenylcarbene complexes lead under the
same reaction conditions to five- and seven-membered car-
bocycles by formal [3+2] and [4+3] carbocyclization reac-
tions, with the substitution pattern on the 1-aminodiene re-
sponsible for the formation of the five- or seven-membered
ring. On the other hand, reaction of alkynylcarbene chromi-
um complexes with 1-aminodienes generates benzaldehyde
or indene derivatives, with the substituent bound to the al-
kynyl moiety, phenyl, or alkenyl groups responsible for the
formation of one or other product. Moreover, mechanistical
proposals for all cyclization patterns have been discussed.
Finally, it is important to point out the simplicity of the
starting materials, 1-aminodienes, and Fischer-type carbene
complexes.
Experimental Section
General: All reactions involving organometallic species were carried out
under an atmosphere of dry N2 by using oven-dried glassware and syring-
es. THF and Et2O were distilled from sodium benzophenone ketyl under
N2 immediately prior to use. TLC was performed on aluminum-backed
plates coated with silica gel 60 with F254 indicator (Scharlab). Flash
column chromatography was carried out on commercial and deactivated
silica gel 60, 230–240 mesh (deactivated silica gel was prepared as fol-
lows: silica gel (125 g) was stirred with a 4% aqueous solution of
K2HPO4 (500 mL) for 3h; after filtration, the resulting solid was oven-
dried at 1008C for 2 d). 1H NMR (200, 300 MHz) and 13C NMR (50.5,
75.5 MHz) spectra were measured at room temperature on Bruker AC-
200, AV-300, and DPX-300 instruments, with tetramethylsilane (TMS)
Scheme 8. Mechanistic proposal for the formation of benzaldehyde and
indene derivatives 11 and 12.
a successive Michael addition of the distal carbon atom of
the 1-aminodiene 2 to the alkynylcarbene complex 10 and
further cyclization, giving intermediate 19. Subsequent elim-
ination of diisopropylamine would lead to arylcarbene com-
plexes 20. The evolution of these intermediates depends on
the nature of the R3 substituent. In the case that R3 is a
phenyl group, the diisopropylamine generated in the aroma-
tization process could be added to the carbene carbon atom
of 20, giving the intermediate 21, which could undergo a re-
ductive elimination to afford the addition product 22. Final
acid hydrolysis would furnish the benzaldehyde derivatives
11. Conversely, when R3 is an alkenyl group, arylcarbene
complexes 20 could evolve through an electrocyclic reaction
leading to cromacyclohexadiene derivatives 23. Subsequent
reductive elimination would afford indene derivatives 12.
The different behavior of intermediate 20 could be attribut-
ed to the increase in activation energy required for the cy-
clopentannulation in a system containing two aromatic rings.
1
(d=0.0 ppm, H NMR spectra) and CDCl3 (d=77.0 ppm, 13C NMR spec-
tra), or C6D6 (d=127.8, 13C NMR) as internal standards. Carbon multi-
plicities were assigned by DEPT techniques. Bidimensional NMR experi-
ments (COSY, HMQC, HMBC, and NOESY) were recorded on
a
Bruker AMX-400 (400 MHz) and AV-600 (600 MHz). High-resolution
mass spectra (HRMS) were determined on a Finnigang MAT95 spec-
trometer.
Materials: Carbene complexes 1a,b,[18] 1c,[19] 5,[20] 7,[21] 10a,[22] and
10b,c[23] were prepared according to literature procedures. 1-Amino-1,3-
dienes were prepared according to the following procedure: The corre-
sponding aldehyde (crotonaldehyde, 3-methyl-2-butenal, or trans-2-
methyl-2-butenal; 10 mmol) was added to a solution of LDA, prepared
from diisopropylamine (12.5 mmol) and BuLi (12.5 mmol, 1.6m hexane
solution) in THF (10 mL) at 08C under an argon atmosphere and the
mixture was stirred 5 min. Chlorotrimethylsilane (15 mmol) was added to
the resulting solution at the same temperature. The mixture was stirred
for 30 min until the temperature reached room temperature. Solvents
were removed and pentane (15 mL) was added to the resulting residue.
The mixture was filtered and the pentane was removed from the filtrate
to give the 1-amino-1,3-dienes 2, which were used without further purifi-
cation.
Conclusion
(E)-N,N-Diisopropyl-1,3-butadien-1-amine (2a): 1H NMR (300 MHz,
C6D6): d=6.61 (dt, J=16.7, 10.3Hz, 1H; C HCH2), 6.35 (d, J=13.3 Hz,
1H; =CHN), 5.37 (dd, J=13.3, 10.5 Hz, 1H; NCH=CH), 5.11 (d, J=
16.7 Hz, 1H; CHH), 4.89 (dd, J=10.5 Hz, 1H; CHH), 3.27 (heptet, J=
We have described the reaction of Group 6 carbene com-
plexes and 1-amino-1,3-butadienes. The reaction outcome
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329

F. J. FaÇanµs, F. Aznar et al.
6.7 Hz, 2H; 2”CHN), 0.91 ppm (d, J=6.7 Hz, 12H; 4”Me); 13C NMR
(DEPT, 75.5 MHz, C6D6): d=138.5 (CH), 136.3 (CH), 103.1 (CH2), 99.2
(CH), 45.7 (CH), 21.3ppm (CH 3).
CHCOMe), 1.34 (dd, J=10.2, 5.9 Hz, 1H; CHHCOMe), 1.12 ppm (t, J=
6.3Hz, 1H; CH HCOMe); 13C NMR (DEPT, 75 MHz, CDCl3): d=201.1
(CH), 137.8 (C), 133.9 (C), 133.0 (C), 128.3 (CH), 127.8 (CH), 127.7
(CH), 127.6 (CH), 126.8 (CH), 126.1 (CH), 125.1 (CH), 67.6 (C), 54.4
(CH3), 43.8 (CH2), 20.1 (CH), 14.7 ppm (CH2).
(E)-N,N-Diisopropyl-3-methyl-1,3-butadien-1-amine
(2b):
1H NMR
(300 MHz, C6D6): d=6.44 (d, J=14.1 Hz, 1H; =CHN), 5.49 (d, J=
14.1 Hz, 1H; NCH=CH), 4.97 (brs, 1H; CHH), 4.80 (brs, 1H; CHH),
3.38 (heptet, J=6.7 Hz, 2H; 2”CHN), 2.03(s, 3H; MeC =), 0.91 ppm (d,
J=6.7 Hz, 12H; 4”MeCH); 13C NMR (DEPT, 75.5 MHz, C6D6): d=
142.7 (C), 132.2 (CH), 104.9 (CH2), 100.7 (CH), 45.8 (CH), 21.3(CH 3),
19.6 ppm (CH3).
A
tenamine (4a): Aminodiene 2b (84 mg, 0.5 mmol) and carbene complex
1c (121 mg, 0.4 mmol) afforded 4a (69 mg, 62%) as a colorless oil. Rf:
0.57 (hexane/ethyl acetate 3:1); 1H NMR (300 MHz, CDCl3): d=7.43(d,
J=1.8 Hz, 1H; =CHO), 6.32 (dd, J=3.1, 1.8 Hz, 1H; CH=CHO), 6.28
(d, J=3.1 Hz, 1H; CHCH=CHO), 5.43(brs, 1H; =CH), 4.05 (brs, 1H; =
CHCHN), 3.14–2.91 (m, 2H; 2”NCHMe), 3.05 (s, 3H; OMe), 2.83 (d,
J=17.3Hz, 1H; C HH), 2.57 (d, J=17.3Hz, 1H; CH H), 1.84 (s, 3H;
MeC=), 0.93(d, J=6.0 Hz, 6H; 2”NCHMeMe), 0.85–0.60 ppm (m, 6H;
2”NCHMeMe); 13C NMR (DEPT, 75 MHz, CDCl3): d=154.4 (C), 141.7
(CH), 137.1 (C), 128.0 (CH), 109.5 (CH), 109.4 (CH), 88.4 (C), 72.2
(CH), 51.3(CH 3), 45.6 (br; CH), 41.6 (CH2), 23.1 (br; CH3), 22.1 (CH3),
17.0 ppm (CH3); HRMS (70 eV, EI): m/z: calcd for C17H27NO2: 277.2036
[M+]; found: 277.2038.
(E)-N,N-Diisopropyl-2-methyl-1,3-butadien-1-amine
(2c):
1H NMR
(300 MHz, C6D6): d=6.59 (dd, J=16.5, 10.6 Hz, 1H; CHCH2), 6.08 (s,
1H; =CHN), 5.05 (d, J=16.5 Hz, 1H; CHH), 4.90 (d, J=10.6 Hz, 1H;
CHH), 3.24 (heptet, J=6.8 Hz, 2H; 2”CHN), 1.90 (s, 3H; MeC=),
0.91 ppm (d, J=6.8 Hz, 12H; 4”MeCH); 13C NMR (DEPT, 75.5 MHz,
C6D6): d=141.9 (CH), 136.1 (CH), 115.6 (C),104.9 (CH2), 48.4 (CH), 21.7
(CH3), 12.7 ppm (CH3).
General procedure for the preparation of compounds 3, 4, 6, 8, 9, 11, and
12: Carbene complexes 1, 5, 7, or 10 (0.4 mmol) were added to a solution
of the corresponding 1-amino-1,3-diene 2 (0.5 mmol) in THF (or diethyl
ether) (10 mL) under an argon atmosphere at 08C (508C for alkynylcar-
bene complexes 10). The mixture was stirred for 30 min until the temper-
ature reached room temperature. The reaction mixture was quenched
with a small amount of silica gel, solvents were removed and the result-
ing residue was purified by flash column chromatography on silica gel
(hexanes/ethyl acetate 40:1 to 10:1) to give compounds 3, 4, 6, 8, 9, 11,
and 12.
A
tenamine (4b): Aminodiene 2c (84 mg, 0.5 mmol) and carbene complex
1c (121 mg, 0.4 mmol) afforded 4b (67 mg, 60%) as a colorless oil. Rf:
0.60 (hexane/ethyl acetate 3:1); 1H NMR (400 MHz, CDCl3): d=7.39
(brs, 1H; =CHO), 6.30 (d, J=3.1 Hz, 1H; CH=CHO), 6.18 (d, J=
3.1 Hz, 1H; CHCH=CHO), 5.47 (brs, 1H; =CH), 3.79 (brs, 1H; =
CHCHN), 3.32–3.19 (m, 1H; NCHMe), 3.07 (s, 3H; OMe), 3.03–2.82 (m,
1H; NCHMe), 2.76 (d, J=16.0 Hz, 1H; CHH), 2.50 (d, J=16.0 Hz, 1H;
CHH), 1.66 (s, 3H; MeC=), 1.16 (d, J=6.6 Hz, 6H; 2”NCHMeMe),
1.03–0.95 ppm (m, 6H; 2”NCHMeMe); 13C NMR (DEPT, 100 MHz,
CDCl3): d=159.2 (C), 141.7 (CH), 140.5 (C), 123.0 (CH), 109.6 (CH),
106.6 (CH), 82.4 (C), 70.3(CH), 51.8 (CH 3), 46.8 (br, CH), 43.6 (br;
CH), 39.5 (CH2), 23.4 (br; CH3), 22.7 (br; CH3), 15.8 ppm (CH3); HRMS
(70 eV, EI): m/z: calcd for C17H27NO2: 277.2036 [M+]; found: 277.2029.
2-[(1R*,2S*)-2-Methoxy-2-phenylcyclopropyl]acetaldehyde (3a): Amino-
diene 2a (77 mg, 0.5 mmol) and carbene complex 1a (125 mg, 0.4 mmol)
afforded 3a (47 mg, 62%) as a colorless oil. Rf: 0.46 (hexane/ethyl ace-
tate 3:1); 1H NMR (300 MHz, CDCl3): d=9.67 (t, J=1.6 Hz, 1H; CH=
O), 7.41–7.32 (m, 5H; ArH), 3.18 (s, 3H; OMe), 2.17 (ddd, J=17.8, 7.2,
1.6 Hz, 1H; CHHCHO), 2.02, (ddd, J=17.8, 7.2, 1.6 Hz, 1H;
CHHCHO), 1.79 (dtd, J=10.1, 7.2, 6.1 Hz, 1H; CHCOMe), 1.30 (dd, J=
10.1, 6.1 Hz, 1H; CHHCOMe), 1.00 ppm (t, J=6.1 Hz, 1H;
CHHCOMe); 13C NMR (DEPT, 75 MHz, CDCl3): d=201.2 (CH), 136.2
(C), 128.9 (CH), 128.3(CH), 127.9 (CH), 79.8 (C), 54.3(CH 3), 43.9
(CH2), 20.0 (CH), 14.9 ppm (CH2); HRMS (70 eV, EI): m/z: calcd for
C11H13O: 161.0960 [M+ÀCHO]; found: 161.0958.
2-[(1R*,2S*)-2-Methoxy-1-methyl-2-phenylcyclopropyl]acetaldehyde
(3b): Aminodiene 2b (84 mg, 0.5 mmol) and carbene complex 1a
(125 mg, 0.4 mmol) afforded 3b (57 mg, 70%) as a colorless oil. Rf: 0.49
(hexane/ethyl acetate 3:1); 1H NMR (300 MHz, CDCl3): d=9.61 (t, J=
2.2 Hz, 1H; CH=O), 7.42–7.32 (m, 5H; ArH), 3.18 (s, 3H; OMe), 2.13
(dd, J=16.8, 2.2 Hz, 1H; CHHCHO), 1.92 (dd, J=16.8, 2.2 Hz, 1H;
CHHCHO), 1.45 (s, 3H; MeC), 1.26 (d, J=6.1 Hz, 1H; CHHCOMe),
0.90 ppm (d, J=6.1 Hz, 1H; CHHCOMe); 13C NMR (DEPT, 75 MHz,
CDCl3): d=202.1 (CH), 137.5 (C), 128.8 (CH), 128.3 (CH), 127.7 (CH),
70.0 (C), 54.7 (CH3), 49.6 (CH2), 28.1 (C), 20.1 (CH2), 14.9 ppm (CH3);
HRMS (70 eV, EI): m/z: calcd for C12H15O: 175.1117 [M+ÀCHO];
found: 175.1115.
(1R*,5R*)-N,N-Diisopropyl-5-methoxy-5-[(E)-styryl]-2-cyclopentena-
mine (6a): Aminodiene 2a (77 mg, 0.5 mmol) and carbene complex 5a
(188 mg, 0.4 mmol) afforded 6b (93mg, 78%, 65% de (de=diastereo-
meric excess) in Et2O; 97 mg, 81%, 87% de in THF) as a colorless oil.
Rf: 0.34 (hexane/ethyl acetate 5:1). 1H NMR (300 MHz, C6D6): d=7.29–
7.02 (m, 5H; ArH), 6.48 (d, J=16.3Hz, 1H; CH =CHAr), 6.35 (d, J=
16.3Hz, 1H; C H=CHAr), 5.68 (ddt, J=6.0, 3.9, 2.0 Hz, 1H; =CHCHN),
5.62 (dq, J=6.0, 2.0 Hz, 1H; =CHCH2), 3.78 (ddd, J=3.9, 2.0, 1.0 Hz,
1H; NCHC=), 3.15 (heptet, J=6.6 Hz, 1H; NCHMe), 3.13 (s, 3H;
OMe), 2.52 (dq, J=16.7, 2.0 Hz, 1H; CHH), 2.27 (dtd, J=16.7, 2.2,
1.0 Hz, 1H; CHH), 1.15 (d, J=6.6 Hz, 1H; 2”MeCH), 0.96 ppm (d, J=
6.6 Hz, 1H; 2”MeCH); 13C NMR (DEPT, 75.5 MHz, C6D6): d=137.6
(C), 134.9 (CH), 134.0 (CH), 128.6 (CH), 128.4 (CH), 127.6 (CH), 127.1
(CH), 126.4 (CH), 85.6 (C), 69.0 (CH), 51.5 (CH3), 46.1 (CH), 39.3
(CH2), 23.6 (CH3), 22.6 ppm (CH3); HRMS (70 eV, EI): m/z: calcd for
C20H29NO: 299.2244 [M+]; found: 299.2243.
A
pentenamine (6b): Aminodiene 2b (84 mg, 0.5 mmol) and carbene com-
plex 5a (188 mg, 0.4 mmol) afforded 6a (102 mg, 81%, 68% de in Et2O;
112 mg, 89%, 90% de in THF) as a colorless oil. Rf: 0.45 (hexane/ethyl
acetate 5:1); 1H NMR (300 MHz, C6D6): d=7.34–7.02 (m, 5H; ArH),
6.52 (d, J=16.4 Hz, 1H; PhCH=CH), 6.39 (d, J=16.4 Hz, 1H; PhCH=
CH), 5.32 (brs, 1H; MeC=CH), 3.82 (brs, 1H; CHN), 3.28–3.12 (m, 2H;
2”NCHMe), 3.18 (s, 3H; OMe), 2.51 (d, J=16.4 Hz, 1H; CHH), 2.16 (d,
J=16.4 Hz, 1H; CHH), 1.64 (s, 3H; MeC=), 1.18 (d, J=6.7 Hz, 6H; 2”
NCHMeMe), 1.02 ppm (d, J=6.7 Hz, 6H; 2”NCHMeMe); 13C NMR
(DEPT, 75.5 MHz, C6D6): d=137.6 (C), 136.9 (C), 135.2 (CH), 128.6
(CH), 128.2 (CH), 127.7 (CH), 127.2 (CH), 126.5 (CH), 86.7 (C), 69.4
(CH), 51.5 (CH3), 46.2 (CH), 43.5 (CH2), 23.7 (CH3), 22.6 (CH3),
17.1 ppm (CH3); HRMS (70 eV, EI): m/z: calcd for C21H31NO: 313.2406
[M+]; found: 313.2413.
2-[(1R*,2S*)-2-Methoxy-2-phenylcyclopropyl]propanal (3c): Aminodiene
2c (84 mg, 0.5 mmol) and carbene complex 1a (125 mg, 0.4 mmol) afford-
ed 3c (60 mg, 73%, de) as a colorless oil. Rf: 0.51 (hexane/ethyl acetate
3:1); 1H NMR (300 MHz, CDCl3): d=9.68 (s, 1H; CH=O), 7.48–7.32 (m,
5H; ArH), 3.18 (s, 3H; OMe), 1.42 (m, 1H; CHMe), 1.29 (m, 1H;
CHCOMe), 1.05 (t, J=6.8 Hz, 1H; CHHCOMe), 0.96 (d, J=6.7 Hz, 1H;
MeCH), 0.92 ppm (dd, J=13.7, 6.8 Hz, 1H; CHHCOMe); 13C NMR
(DEPT, 75 MHz, CDCl3): d=203.8 (CH), 136.1 (C), 128.8 (CH), 128.3
(CH), 127.8 (CH), 67.3(C), 54.4 (CH 3), 46.3(CH 2), 28.0 (CH), 13.7
(CH2), 13.0 ppm (CH3).
2-[(1R*,2S*)-2-Methoxy-2-(2-naphthyl)cyclopropyl]acetaldehyde
(3d):
Aminodiene 2a (77 mg, 0.5 mmol) and carbene complex 1b (145 mg,
0.4 mmol) afforded 3d (50 mg, 52%) as a colorless oil. Rf: 0.42 (hexane/
ethyl acetate 3:1). 1H NMR (300 MHz, CDCl3): d=9.64 (t, J=1.5 Hz,
1H; CH=O), 7.96–7.67 (m, 4H; ArH), 7.61–7.40 (m, 3H; ArH), 3.19 (s,
3H; OMe), 2.20 (ddd, J=12.5, 7.0, 1.5 Hz, 1H; CHHCHO), 2.11 (ddd,
J=12.5, 7.0, 1.5 Hz, 1H; CHHCHO), 1.83(dtd, J=10.2, 7.0, 6.6 Hz, 1H;
(1R*,5R*)-5-[(E)-(2-Furyl)ethenyl]-N,N-diisopropyl-5-methoxy-3-methyl-
2-cyclopentenamine (6c): Aminodiene 2b (84 mg, 0.5 mmol) and carbene
complex 5b (184 mg, 0.4 mmol) afforded 6c (104 mg, 86%, 60% de in
Et2O; 97 mg, 80%, 80% de in THF) as a colorless oil. Rf: 0.20 (hexane/
330
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Chem. Eur. J. 2008, 14, 325 – 332

Three-, Five-, Six-, and Seven-Membered Rings
FULL PAPER
ethyl acetate 5:1); 1H NMR (300 MHz, C6D6): d=7.03(d, J=1.8 Hz, 1H;
=CHO), 6.54 (d, J=16.4 Hz, 1H; 2-FuCH=CH), 6.37 (d, J=16.4 Hz, 1H;
2-FuCH=CH), 6.08 (dd, J=3.3, 1.8 Hz, 1H; CH=CHO), 6.02 (d, J=
3.3 Hz, 1H; CHCH=CHO), 5.29 (brs, 1H; MeC=CH), 3.81 (brs, 1H; =
24.9 ppm (CH2); HRMS (70 eV, EI): m/z: calcd for C11H16O3: 196.1099
[M+]; found: 196.1105.
2-{(4aS*,5S*)-2,3,4,4a,5,6-Hexahydro-7-methoxycyclopenta[b]pyran-5-
yl}propanal (8b): Aminodiene 2b (84 mg, 0.5 mmol) and carbene com-
plex 7 (180 mg, 0.4 mmol) afforded 8b (66 mg, 79%, 1:1 mixture of dia-
stereoisomers) as a colorless oil. Rf: 0.30 (hexane/ethyl acetate 5:1);
1H NMR (200 MHz, C6D6): d=9.29, 9.28 (2s, 2H; 2”CHO), 3.90–3.70
(m, 2H; 2”CHHO), 3.86 (s, 6H; 2”OMe), 3.21 (app.ddd, J=12.8, 10.5,
2.3Hz, 2H; 2”CH HO), 2.20–0.80 (m, 18H; 2”CH2CH2CHCH-
CCHN), 3.15 (heptet, J=6.7 Hz, 2H; 2”N
2.49 (d, J=16.4 Hz, 1H; CHH), 2.09 (d, J=16.4 Hz, 1H; CHH), 1.60 (s,
3H; MeC=), 1.19 (d, J=6.7 Hz, 6H; 2”N(CHMeMe), 1.01 (d, J=6.7 Hz,
6H; 2”N
(CHMeMe); 13C NMR (DEPT, 75.5 MHz, C6D6): d=153.3 (C),
A
AHCTREUNG
ACHTREUNG
141.5 (CH), 136.9 (C), 134.5 (CH), 128.1 (CH), 116.7 (CH), 111.3 (CH),
107.2 (CH), 86.2 (C), 69.4 (CH), 51.6 (CH3), 46.0 (CH), 43.9 (CH2), 23.5
(CH3), 22.7 (CH3), 17.0 ppm (CH3); HRMS (70 eV, EI): m/z: calcd for
C19H29NO2: 303.2198 [M+]; found: 303.2203.
A
(DEPT, 100 MHz, C6D6): d=202.9 (CH), 202.6 (CH), 133.0 (C), 132.9
(C), 129.4 (C), 68.8 (CH2), 57.5 (CH3), 57.5 (CH3), 50.2 (CH), 50.1 (CH),
41.9 (CH), 41.2 (CH), 40.3 (CH), 40.0 (CH), 33.0 (CH2), 32.3 (CH2), 31.7
(CH2), 31.6 (CH2), 25.0 (CH2), 25.0 (CH2), 11.1 (CH3), 11.0 ppm (CH3).
A
2-cyclopentenamine diast-(6c): Rf: 0.50 (hexane/ethyl acetate 5:1);
1H NMR (300 MHz, C6D6): d=7.14 (d, J=1.8 Hz, 1H; =CHO), 6.73(d,
J=16.6 Hz, 1H; 2-FuCH=CH), 6.42 (d, J=16.6 Hz, 1H; 2-FuCH=CH),
6.23–6.15 (m, 2H; CH=CHO, CHCH=CHO), 5.49 (brs, 1H; MeC=CH),
4.33 (brs, 1H; =CCHN), 3.20 (s, 3H; OMe), 2.92 (heptet, J=6.5 Hz, 2H;
2”NCHMe, 2.41 (s, 2H; CH2), 1.76 (s, 3H; MeC=), 1.22 (d, J=6.5 Hz,
6H; 2”NCHMeMe), 1.03ppm (d, J=6.5 Hz, 6H; NCHMeMe);
13C NMR (DEPT, 75.5 MHz, C6D6): d=153.6 (C), 141.8 (CH), 137.5 (C),
132.2 (CH), 128.6 (CH), 118.4 (CH), 111.2 (CH), 107.0 (CH), 89.3 (C),
72.4 (CH), 50.6 (CH3), 45.9 (CH), 41.5 (CH2), 23.5 (CH3), 22.1 (CH3),
15.7 ppm (CH3); HRMS (70 eV, EI): m/z: calcd for C19H29NO2: 303.2198
[M+]; found: 303.2187.
(4aS*,5R*)-2,3,4,4a,5,8-Hexahydro-N,N-diisopropyl-9-methoxy-7-methyl-
cyclohepta[b]pyran-5-amine (9): Aminodiene 2c (84 mg, 0.5 mmol) and
carbene complex 7 (180 mg, 0.4 mmol) afforded 9 (81 mg, 69%) as a col-
1
orless oil. Rf: 0.52 (hexane/ethyl acetate 5:1); H NMR (400 MHz, C6D6):
d=5.57 (brs, 1H; CH=), 3.83–3.70 (m, 2H; CH2O), 3.68 (s, 3H; OMe),
3.39 (d, J=17.4 Hz, 1H; CHHCMe), 3.38–3.26 (m, 3H; =CCHN, 2”
NCHMe), 2.66–2.48 (m, 1H; CHCHN), 2.41 (d, J=17.4 Hz, 1H;
CHHCMe), 1.86 (s, 3H; Me), 1.85–1.60 (m, 3H; C H2CH2O, CHHCH),
1.60–1.45 (m, 1H; CHHCH), 1.14 (d, J=6.8 Hz, 6H; 2”NCHMeMe),
1.03ppm (d, J=6.5 Hz, 6H; 2”NCHMeMe); 13C NMR (DEPT,
100 MHz, C6D6): d=138.9 (C), 133.8 (C), 128.2 (CH), 127.7 (CH), 68.6
(CH2), 58.6 (CH3), 54.6 (CH), 46.6 (CH), 42.1 (CH), 35.2 (CH2), 26.6
(CH3), 24.8 (CH2), 24.4 (CH2), 23.9 (CH3), 21.8 ppm (CH3); HRMS
(70 eV, EI): m/z: calcd for C18H31NO2: 293.2355 [M+]; found: 293.2351.
A
pentenamine (6d): Aminodiene 2c (84 mg, 0.5 mmol) and carbene com-
plex 5a (188 mg, 0.4 mmol) afforded 6d (92 mg, 73%, >95% de) as a
colorless oil. Rf: 0.36 (hexane/ethyl acetate 5:1); 1H NMR (300 MHz,
C6D6): d=7.29–7.04 (m, 5H; ArH), 6.51 (d, J=16.4 Hz, 1H; PhCH=
CH), 6.35 (d, J=16.4 Hz, 1H; PhCH=CH), 5.40–5.36 (m, 1H; MeC=
CH), 3.54 (s, 1H; =CCHN), 3.21–2.97 (m, 2H; 2”NCHMe), 3.11 (s, 3H;
OMe), 2.45–2.21 (m, 2H; CH2), 1.70 (d, J=1.6 Hz, 3H; =CMe), 1.29 (d,
J=6.7 Hz, 6H; 2”NCHMeMe), 1.02 ppm (d, J=6.7 Hz, 6H; 2”
NCHMeMe); 13C NMR (DEPT, 75.5 MHz, C6D6): d=141.0 (C), 137.6
(CH), 135.9 (CH), 128.6 (CH), 127.3 (CH), 127.1 (CH), 126.4 (CH),
Biphenyl-2-carbaldehyde (11a): Aminodiene 2a (77 mg, 0.5 mmol) and
carbene complex 10a (134 mg, 0.4 mmol) afforded 11a (48 mg, 66%) as
a colorless oil. The analytical data are identical to those described in the
literature.[24]
5-Methylbiphenyl-2-carbaldehyde (11b): Aminodiene 2b (84 mg,
0.5 mmol) and carbene complex 10a (134 mg, 0.4 mmol) afforded 11b
(55 mg, 70%) as a colorless oil. Rf: 0.50 (hexane/ethyl acetate 5:1);
1H NMR (300 MHz, CDCl3): d=9.98 (s, 1H; CHO), 7.99 (d, J=8.0 Hz,
1H; ArH), 7.51–7.33 (m, 6H; ArH), 7.30 (s, 1H; ArH), 2.50 ppm (s, 3H;
Me); 13C NMR (DEPT, 75 MHz, CDCl3): d=192.0 (CH), 146.0 (C), 144.4
(C), 137.8 (C), 131.4 (C), 131.2 (CH), 129.9 (CH), 128.5 (CH), 128.2
(CH), 127.9 (CH), 127.5 (CH), 21.7 ppm (CH3).
123.1 (CH), 84.3(C), 72.4 (CH), 51.3(CH
3), 48.1 (br; CH), 44.7 (br;
CH), 39.4 (CH2), 24.9 (br; CH3), 23.0 (br; CH3), 15.7 ppm (CH3); HRMS
(70 eV, EI): m/z: calcd for C21H31NO: 313.2406 [M+]; found: 313.2415.
A
2-cyclopentenamine (6e): Aminodiene 2b (84 mg, 0.5 mmol) and carbene
complex 5b (184 mg, 0.4 mmol) afforded 6e (86 mg, 71%, 80% de) as a
colorless oil. Rf: 0.36 (hexane/ethyl acetate 5:1); 1H NMR (300 MHz,
C6D6): d=7.00 (d, J=1.6 Hz, 1H; =CHO), 6.54 (d, J=16.0 Hz, 1H; 2-
FuCH=CH), 6.37 (d, J=16.0 Hz, 1H; 2-FuCH=CH), 6.07 (dd, J=3.5,
1.6 Hz, 1H; CH=CHO), 5.97 (d, J=3.5 Hz, 1H; CHCH=CHO), 5.33–
5.29 (m, 1H; MeC=CH), 3.52 (brs, 1H; =CCHN), 3.20–2.90 (m, 2H; 2”
NCHMe), 3.09 (s, 3H; OMe), 2.36 (brd, J=16.0 Hz, 1H; CHH), 2.19
(app.d, J=16.0 Hz, 1H; CHH), 1.64 (d, J=1.5 Hz, 3H; Me), 1.24 (d, J=
6.3Hz, 6H; 2”NCH MeMe), 0.98 ppm (d, J=6.7 Hz, 6H; 2”
NCHMeMe); 13C NMR (DEPT, 75.5 MHz, C6D6): d=153.3 (C), 141.4
(CH), 141.0 (C), 135.2 (CH), 123.0 (CH), 115.9 (CH), 111.3 (CH), 107.1
(CH), 84.1 (C), 72.4 (CH), 51.3(CH 3), 47.9 (br; CH), 44.6 (br; CH), 39.4
(CH2), 24.8 (br; CH3), 23.1 (br; CH3), 15.7 ppm (CH3); HRMS (70 eV,
EI): m/z: calcd for C19H29NO2: 303.2198 [M+]; found: 303.2204.
4-Methylbiphenyl-2-carbaldehyde (11c): Aminodiene 2c (84 mg,
0.5 mmol) and carbene complex 10a (134 mg, 0.4 mmol) afforded 11c
(57 mg, 72%) as a colorless oil. Rf: 0.50 (hexane/ethyl acetate 5:1);
1H NMR (300 MHz, CDCl3): d=10.00 (s, 1H; CHO), 7.89 (s, 1H; ArH),
7.57–7.26 (m, 7H; ArH), 2.49 ppm (s, 3H; Me); 13C NMR (DEPT,
75 MHz, CDCl3): d=192.6 (CH), 139.9 (C), 137.8 (C), 137.6 (C), 134.3
(CH), 133.4 (C), 130.6 (CH), 130.0 (CH), 128.2 (CH), 127.8 (CH), 127.6
(CH), 20.9 ppm (CH3).
1,2,3,4-Tetrahydro-9-methoxy-6-methyl-4H-fluorene (12a): Aminodiene
2b (84 mg, 0.5 mmol) and carbene complex 10c (136 mg, 0.4 mmol) af-
forded 12b (52 mg, 61%) as a colorless oil. Rf: 0.58 (hexane/ethyl acetate
3:1); 1H NMR (300 MHz, CDCl3): d=7.72 (d, J=7.8 Hz, 1H; ArH), 7.32
(d, J=7.8 Hz, 1H; ArH), 6.96 (s, 1H; ArH), 4.88 (s, 1H; OCH), 3.07 (s,
3H; OMe), 2.40 (s, 3H; MeC), 1.83–1.62 ppm (m, 8H; aliphatic ring);
13C NMR (DEPT, 75 MHz, CDCl3): d=137.9 (C), 137.0 (C), 136.6 (C),
130.2 (C), 127.4 (C), 125.2 (CH), 123.2 (CH), 118.6 (CH), 83.5 (CH), 51.9
(CH3), 29.6 (CH2), 23.4 (CH2), 22.7 (CH2), 22.3(CH 2), 21.5 ppm (CH3).
2-{(4aS*,5S*)-2,3,4,4a,5,6-Hexahydro-7-methoxycyclopenta[b]pyran-5-
yl}ethanal (8a): Aminodiene 2a (77 mg, 0.5 mmol) and carbene complex
7 (180 mg, 0.4 mmol) afforded 8a (60 mg, 76%) as a colorless oil. Rf:
0.27 (hexane/ethyl acetate 5:1); 1H NMR (600 MHz, C6D6): d=9.35 (t,
J=1.6 Hz, 1H; CHO), 3.85 (ddt, J=10.6, 4.4, 1.7 Hz, 1H; CHHO), 3.81
(s, 3H; OMe), 3.27 (ddd, J=12.9, 10.6, 2.3Hz, 1H; CH HO), 2.47–2.43
(m, 1H; CHHCOMe), 2.05 (ddd, J=15.7, 4.8, 1.6 Hz, 1H; CHHCH=O),
1.98–1.87 (m, 4H; CHHCOMe, CHHCH=O, CHCO, CHCH2CH=O),
1.75 (dqd, J=12.9, 3.5, 1.7 Hz; 1H; CHHCHCO), 1.41 (qdd, J=12.9,
4.4,3.6 Hz, 1H; CHHCH2CH2O), 1.24–1.19 (m, 1H; CHHCH2CH2O),
0.92 ppm (qd, J=12.9, 3.6, 1H; CHHCHCO); 13C NMR (DEPT,
150 MHz, C6D6): d=200.1 (CH), 132.9 (C), 129.5 (C), 68.7 (CH2), 57.5
(CH3), 48.6 (CH2), 43.9 (CH), 34.8 (CH2), 34.1 (CH), 30.9 (CH2),
3-Methoxy-2-phenyl-1H-indene (12b): Aminodiene 2a (77 mg, 0.5 mmol)
and carbene complex 10d (145 mg, 0.4 mmol) afforded 12c (49 mg, 55%)
as a colorless oil. Rf: 0.51 (hexane/ethyl acetate 3:1); 1H NMR (300 MHz,
CDCl3): d=7.80 (d, J=8.3Hz, 1H; ArH), 7.51–7.13(m, 8H; ArH), 3.97
(s, 3H; OMe), 3.66 ppm (s, 2H; CH 2); 13C NMR (DEPT, 75 MHz,
CDCl3): d=141.1 (C), 140.8 (C), 135.2 (C), 128.3 (CH), 128.0 (C), 126.7
(CH), 126.5 (CH), 126.3(CH), 125.3(CH), 124.6 (C), 123.9 (CH), 118.5
(CH), 58.8 (CH3), 36.1 ppm (CH2).
Chem. Eur. J. 2008, 14, 325 – 332
ꢀ 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
331

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Received: July 18, 2007
Published online: September 21, 2007
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