Silver-catalyzed stereoselective [3+2] cycloadditions of cyclopropyl-indanimines with carbonyl compounds

Article abstract of DOI:10.1002/adsc.201300090

Silver-catalyzed stereoselective [3+2] cycloadditions between mono-substituted cyclopropyl-indanimines and aldehydes are reported. The stereochemical course of the reaction is rationalized with a cyclic transition state. The resulting indanimine cycloadducts are not readily hydrolyzed unless external aldehydes are present with the silver catalyst. Notably, this hydrolysis process leads to a change of stereochemistry for the resulting indanone products. Copyright

Full text of DOI:10.1002/adsc.201300090

COMMUNICATIONS
DOI: 10.1002/adsc.201300090
Silver-Catalyzed Stereoselective [3+2]Cycloadditions of
Cyclopropyl-Indanimines with Carbonyl Compounds
Hsiao-Hua Hung,a Yi-Ching Liao,a and Rai-Shung Liua,*
a
Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan, Republic of China
Fax : (+886)-3-571-1082; e-mail: rsliu@mx.nthu.edu.tw
Received: January 30, 2013; Revised: March 28, 2013; Published online: May 15, 2013
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201300090.
Abstract: Silver-catalyzed stereoselective [3+2]cy-
cloadditions between mono-substituted cyclopropyl-
indanimines and aldehydes are reported. The ste-
reochemical course of the reaction is rationalized
with a cyclic transition state. The resulting indan-
a single-group activation may be inferred from the re-
cently reported gold-catalyzed [2+2+n]cycloaddi-
tions (n=2, 3) of 1,6-enynes with dipolarophiles,[5] in
which gold carbene intermediates I react with alde-
hydes and nitrones to give cycloadducts [Eq. (2)]. No-
tably, the activity of gold carbene species I is attribut-
ACHTUNGTRENNUNGimine cycloadducts are not readily hydrolyzed
unless external aldehydes are present with the
silver catalyst. Notably, this hydrolysis process leads
to a change of stereochemistry for the resulting in-
danone products.
ed to its strained bicycloACTHNGUTRENNU[G 3.1.0]hexane framework to
show a significant character of alkenyl-gold carbocat-
ion I’.[4–6] We sought to accomplish a new [3+2]cyclo-
addition via a single-group activation on cyclopropane
derivatives bearing a similar framework.
Keywords: carbonyl compounds;
tions; cyclopropyl-indanimines; hydrolysis; silver
catalysis
[3+2] cycloaddi-
Our initial work was aimed at bicyclo-
ACHTUNGTREN[NGNU 3.1.0]hexanones 2 that are readily available from the
gold-catalyzed oxidative cyclizations of 1,5-enynes 1,
as depicted in Scheme 1.[7a] Nevertheless, these ke-
tones failed to undergo [3+2]cycloadditions with al-
dehydes in the presence of Lewis acids including the
[2]
otherwise effective Sn
G
and AgNTf2. We
Cyclopropanes bearing a donor and acceptor serve as turned our attention to the imine derivatives 3 be-
three-carbon building units in various Lewis-acid cat- cause of their better affinity toward Lewis or Brøn-
alyzed [3+n]cycloaddition reactions.[1] These cyclo-
ACHTUNGTRENsNGNU ted acids. This work reports the stereoselective syn-
propane derivatives generally bear two carbonyl thesis of indanimines 3 via gold-catalyzed iminocycli-
groups to show catalytic activities, particularly with an zations of 1,5-enynes 1, as well as their subsequent
aldehyde and a ketone [Eq. (1)].[2] Such a cyclopro- silver-catalyzed [3+2]cycloadditions with aldehydes.
pane/aldehyde [3+2]cycloaddition was used as a key
Shown in Table 1 is a smooth production of cyclo-
step for the asymmetric syntheses of (+)-polyanthel- propyl-indanimines 3a via the treatment of 1,5-enynes
lin[2d] and (+)-virgatusin.[2e] We are aware of no cyclo- 1 with N-iminopyridinium ylide[8] (1.2 equiv.) in hot
propane derivatives bearing a single electron-with- 1,2-dichloroethane (DCE, 808C, 2.5 h) with IPrAuCl/
drawing group that can undergo a catalytic [3+2]cy- AgNTf2 [IPr=1,3-bis(diisopropylphenyl)imidazol-2-
cloaddition with aldehydes.[3,4] The feasibility of such ylidene, 5 mol%]; the resulting imine product 3a was
Adv. Synth. Catal. 2013, 355, 1545 – 1552
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1545

Hsiao-Hua Hung et al.
COMMUNICATIONS
Scheme 1. Reaction protocols for species 2 and 3.
obtained in 80% yield (Scheme 2). Herein, a gold car-
bene A was postulated as the key intermediate ac-
cording to literature precedents.[7–9] A stereoselective
reduction of imine 3a was achieved with NaBH4
(1.1 equiv.) in methanol to give tosylamine 5a in 97%
yield. The stereochemistry of compound 5a was con-
firmed by an X-ray diffraction study.[10]
Table 1 shows the scope of this iminocyclization on
further 1,5-enynes 1b–1j; the reactions were per-
Table 1. Gold-catalyzed iminocyclization of additional 1,5-
enynes.
Scheme 2. Gold-catalyzed iminocyclization of 1,5-enyne 1a.
formed with IPrAuNTf2 (5 mol%) in hot 1,2-dichloro-
ethane (2.5–5.5 h) using N-iminopyridinium ylide
(1.2 equiv.). This iminocyclization is extendable to 1,5-
enynes bearing a cyclopentylidene and cyclohexyli-
dene group (entries 1 and 2), giving the desired cycli-
zation products 3b and 3c in 85% and 87% yields, re-
spectively. The stereospecificity of this oxidative cycli-
zation is manifested by 1,5-enynes 1d (R1 =Ph, R2 =
Me) and 1e (R1 =Me, R2 =Ph) that delivered indan-
AHCTUNGTREGiNNUN mines 3d and 3e, respectively (entries 3 and 4); this
feature supports the intermediacy of a gold carbene
A.[7–9] We tested the reactions on 1,5-enynes 1f–1i (en-
tries 5–8) bearing chloro and fluoro substituents at
their phenyl C-4 or C5 carbons; their resulting prod-
ucts 3f–3i were obtained in satisfactory yields (68–
77%). For 1,5-enyne 1j bearing Y=OMe, its corre-
sponding product 3j was obtained in 30% yield. This
reaction was not applicable to 1,5-enyne bearing X=
OMe because its alkyne was too electron-rich to be
activated.
With a suitable indanimine 3a in hand, we next ex-
amined its [3+2]cycloaddition with benzaldehyde
(5.0 equiv.) in hot and wet 1,2-dichloroethane (DCE,
808C) with commonly used Lewis acid catalysts. As
[a]
[1]=0.05M, IPr=1,3-bis(diisopropylphenyl)imidazol-2-
ylidene.
Product yields are reported after separation on a silica
gel column.
[b]
1546
asc.wiley-vch.de
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2013, 355, 1545 – 1552

Silver-Catalyzed Stereoselective [3+2]Cycloadditions of Cyclopropyl-Indanimines
Table 2. ACHTUNGTRENNUNG[3+2]cycloaddition of benzaldehyde.
using AgNTf2 (10 mol%) in hot dichloroethane
(808C); the results are shown in Table 3. As shown in
entries 1–4, this silver-catalyzed cycloaddition was ap-
plicable to the reactions between indanimine 3a (X=
Y=H) and electron-deficient benzaldehydes (R’=4-
ZC6H4, Z=Cl, Br, CO2Me, and NO2), their resulting
indanimine cycloadducts 4b–4e were obtained in 52–
81% yields. Indanone derivative 4b’ (12%) and 3-
methyl-vinylindanimine 6a (15%) were isolated in
minor proportions, respectively, from 4-chloro- and 4-
methoxycarbonylbenzaldehyde (entries 1 and 3). With
this silver catalyst, electron-rich benzaldehydes (R’=
4-MeOC6H4, 4-t-BuC6H4) delivered the desired cyclo-
adducts 4f and 4g in 44% and 62% yields, respective-
ly (entries 5 and 6); we also isolated a decomposed
product, 3-methylvinylindanimine 6a in 27% yield
with 4-tert-butylbenzaldehyde (entry 6). For isobutyr-
aldehyde, its resulting cycloadduct 4h was obtained in
64% yield (entry 7). This silver-catalyzed [3+2]-cyclo-
addition was applicable to 3-methylbut-3-enal and 2-
thienylaldehyde to give desired indanimines 4i and 4j
in 41% and 67% yields, respectively (entries 8 and 9).
We examined the same reactions on additional inda-
nimines 3f, 3g, 3h and 3i bearing chloro and fluoro
substituents at their phenyl C-4 and C-5 carbons; the
corresponding cycloadducts 4k–4n were obtained in
56–88% yields (entries 10–13). We tested the reac-
tions on cyclopropyl-indanimines 3b and 3c bearing
[a]
[3a]=0.05M.
[b]
Product yields are reported after separation on a silica
gel colomn.
shown in Table 2, we tested the reactions on several a cyclopentylidene and cyclohexylidene group; their
silver salts such as AgSbF6, AgOTf and AgNTf2 indanimine cycloadducts 4o and 4p were obtained in
(10 mol%, entries 1–3) in hot DCE (808C, 2.5–5.0 h), 63% and 57% yields, respectively. The stereochemis-
giving bicyclic ketone 4a’ in 41–83% yields, with try of representative cycloadduct 4l was determined
1
AgNTf2 showing the best efficience (entry 3). Within with the help of H NOE-spectra. The proposed struc-
a brief reaction period (1 h), we managed to obtained ture was confirmed by an X-ray diffraction study[10] of
its primary indanimine 4a in 72% yield, together with compound 4h (entry 7) which showed an all cis-ste-
ketone 4a’ in a minor proportion (5%, entry 4). We reochemistry for the three ring protons.
also tested the reaction on an authentic indanone spe-
To understand the stereochemical course, we tested
cies 2a that was inactive in the presence of AgNTf2 the reactions on two diastereomeric indanimines 3d
and benzaldehyde (5 equiv.) (entry 5). We investigat- and 3e. Each diastereomeric indanimine gave a mix-
ed the same reactions with Cu
each at 10 mol% in hot DCE (808C, 1.5 h), giving former as major species (4q/4r=1.6–2.8:1); the com-
ketone 4a’ in 80–82% yields after work-up. Sc(OTf)3 bined yield were 33% and 66%, respectively
and Zn(OTf)2 gave indanone 4a’ in 78% and 11% (Scheme 3). The structures of indanimines 4q and 4r
ACHTUNGTREN(NUG OTf)2 and SnCAHUTNGTREN(NUNG OTf)2, ture of indanimine cycloadducts 4q and 4r with the
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
1
yields, respectively. The structures of imine 4a and were deduced from the H NOE spectra.
ketone 4a’ were determined by 1H NOE spectra,
We examined this silver-catalyzed reaction between
which revealed that the two compounds have differ- indanimine 3a and acetophenone derivatives (X=H,
ent configurations. Imine 4a has three ring protons in Cl). As Eq. (3) shows, we obtained their correspond-
a mutually cis-orientation whereas ketone 4a’ has its ing products 7a (X=H) and 7b (X=Cl) as single dia-
phenyl group cis to the other two protons. The X-ray stereomers; the yields were 43% and 61% yields, re-
diffraction study[10] confirms the stereochemistry of
ketone 4a’ whereas the structure of imine 4a was also
inferred by X-ray diffraction of its relatives 4h and 7b
(vide infra).[10] Interestingly, silver-catalyzed hydroly-
sis of imine 4a to ketone 4a’ involves an alteration of
stereochemistry.
We tested this cycloaddition with additional indan-
ACHTUNGTRENNUNGimines 3a–3c, 3f–3i and various aldehydes (5 equiv.)
Adv. Synth. Catal. 2013, 355, 1545 – 1552
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
1547

Hsiao-Hua Hung et al.
COMMUNICATIONS
Table 3. Reaction scope for the [3+2]cycloadditions with aldehydes.
[a]
[b]
[3]=0.05M, aldehyde (5 equiv.).
Product yields are reported after separation on a silica gel column.
tered stereochemistry in the presence of benzalde-
hyde (5 equiv.). As shown in Table 4, this hydrolysis is
extendable to indanimines 4o and 4p to deliver indan-
AHCTUNGTERGUNoNN nes 4o’ and 4p’ in 76–78% yields (entries 1 and 2);
1
the structure of species 4o’ was confirmed by its H
NOE spectra. The reactions were suitable to indani-
mines 4k–4n bearing fluoro and chloro substituents at
their phenyl C-4 and C-5 carbons, producing indan-
AHCTUNGTRENNUNG
A
E
ACHTUNGTRENNUNG
Scheme 3. Silver-catalyzed cycloadditions on indanimines 3d
and 3e.
plemented the same hydrolysis as long as benzalde-
hyde is present.
Scheme 4 shows a plausible mechanism to rational-
ize the stereochemical course of the silver-catalyzed
spectively. The stereochemistry of compound 7b was carbonyl cycloaddition. For the initial indanimine 3a,
1
determined by H NOE and X-ray diffraction.[10] The we postulate that Ag+-coordinated indanimine is pres-
ORTEP diagram revealed that species 7b has a cis-ge- ent also as the carbocation resonance form B that co-
ometry between the methyl and its adjacent hydro- ordinates with a carbonyl species to form cyclic transi-
gen; this configuration is consistent with those for the tion states C and D.[11] State C is less sterically hin-
preceding indanimine products in Table 2 and Table 3. dered because it has the axial positions substituted
We then tested the reliability of the silver-catalyzed with small Rs (Rs =small group) and two protons; in
hydrolysis with additional indanimine cycloadducts contrast, state D has an axial Rs group to exert steric
4o, 4p and 4k–4n because this process leads to an al- interaction with the bulky indene ring.
1548
asc.wiley-vch.de
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2013, 355, 1545 – 1552

Silver-Catalyzed Stereoselective [3+2]Cycloadditions of Cyclopropyl-Indanimines
Table 4. Silver-catalyzed hydrative epimerization.
product because its corresponding transition state F
has a small methyl group in the axial position.
Of particular interest is the altered stereochemistry
when the initially formed indanimine 4a was hydro-
lyzed to indanone 4a’ in the presence of AgNTf2 and
benzaldehyde. As shown in Scheme 6, this hydrolysis
was infeasable with p-TSA (p-toluenesulfonic acid,
10 mol%) in hot DCE (808C, 24 h) and water
(2 equiv.), from which unreacted 4a (36%) and 3-
methylvinylindanimine 6a (35%) were recovered. To
understand the mechanism, we heated species 4a with
AgNTf2 (10 mol%) and water (2 equiv.) in hot DCE
for a protracted period (80 h), giving indanone deriva-
tive 4a’ (38%), un-reacted 4a and 3-methylvinylindan-
AHCTUNGTRENNiGUN mine 6a (12%). In the presence of benzaldehyde-d5
(5 equiv.), the AgNTf2-catalyzed hydrolysis of indani-
mine 4a proceeded smoothly to give indanone 4a’ in
84% yield, but containing no deuterium content. This
observation indicates that free cyclopropyl-indan-
AHCTUNGTREGUNiNN mine 3a was not involved in this hydrolysis. We at-
tempted to prepare the imine derivative of 4a’ that is
a diastereomer of imine 4a; but the reaction was un-
successful under standards condition (808C, 48 h, ben-
zene, 5 mol% p-TSA and TsNH2), as depicted in Eq
(4).
[a]
[4]=0.05M, PhCHO (5 equiv.).
Product yields are reported after separation on a silica
[b]
gel column.
In Scheme 3, we observe the ratio of the product
composition 4q/4r=1.6–2.8 using diastereomeric
indan
ꢀ
imines 3d and 3e because of a facile rotation of
Shown in Scheme 7 is a postulated mechanism to
1
2+
C CR R as in intermediate E’ (Scheme 5). We pos- rationalize the altered stereochemistry in the silver-
tulate that this species reacts with benzaldehyde to catalyzed hydrolysis. For initial 4a, its coordination
generate two possible transition states F and G, to with silver ion forms benzylic cation H that activates
give observed products 4q and 4r, respectively. a retro-Prins rearrangement[12] to give an oxonium in-
Herein, diastereomeric product 4q is the preferable termediate I. We envisage that this intermediate un-
Scheme 4. Stereochemical course of the [3+2]-cycloaddition
Adv. Synth. Catal. 2013, 355, 1545 – 1552
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
1549

Hsiao-Hua Hung et al.
COMMUNICATIONS
Scheme 5. Cycloaddition reactions of diastereomeric species 3d and 3e.
Scheme 6. Control experiments to elucidate the hydrolysis mechanism
Scheme 7. A plausible mechanism for the hydrolysis.
dergoes an intramolecular proton transfer to generate a rapid change of aldehyde orientation to give species
3-methylvinylindanimine 6a together with the release H’ before a Prins cyclization takes place.[13] In con-
of benzaldehyde. Meanwhile, species I undergoes trast with imine 4a, diastereomeric imine H’ seems to
1550
asc.wiley-vch.de
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2013, 355, 1545 – 1552

Silver-Catalyzed Stereoselective [3+2]Cycloadditions of Cyclopropyl-Indanimines
be unstable [see Eq. (4)] because of its steric hin- Typical Procedure for Synthesis of N-{3,3-Dimethyl-1-
drance, and it undergoes a facile hydrolysis to give phenyl-3,3a-dihydro-1H-indeno
ACHTUNGTERNN[UNG 1,2-c]furan-8ACHTUNGERTN(NUGN 8aH)-
the observed indanone 4a’. We speculate that addi- ylidene}-4-methylbenzenesulfonamide (4a)
tional benzaldehyde (5 equiv.) assists the completion
To
a 1,2-dichloroethane (1.6 mL) solution of AgNTf2
of this silver-catalyzed hydrolysis. In the absence of
benzaldehyde, water (2 equiv.) likely attacks the oxo-
nium intermediate I to displace benzaldehyde, ulti-
mately giving undesired 3-methyl-vinylindanimine 6a
via tertiary alcohol intermediates K and L. We specu-
late that external benzaldehyde might impede this
side reaction via reacting with water to form its hy-
drate.
Before this work, the reactions between aldehydes
and monocarbonyl-substituted cyclopropanes required
Lewis acids in excess proportions (1.0 equiv.) to give
products through an addition reaction. Here, we
report a stereoselective Ag(I)-catalyzed [3+2] carbon-
yl cycloaddition for cyclopropyl-indanimines bearing
(7.2 mg, 0.018 mmol) was added a 1,2-dichloroethane solu-
tion (2.0 mL) of compound 3a (60 mg, 0.184 mmol) and ben-
zaldehyde (97.8 mg, 0.92 mmol); the mixture was heated to
808C for 1 h before the solution was filtered over a short
silica bed. The solvent was evaporated under reduced pres-
sure; the crude product was eluted through a silica gel
column to afford indanimine product 4a (yield: 57.2 mg,
0.132 mmol, 72%), and indanone product 4aꢀ (yield: 2.6 mg,
0.009 mmol, 5%) as a white solid. IR (neat): n=2920 (m),
1595 (m), 1577 (s), 1316 (s), 1155 (s), 875 (s), 671 cmꢀ1 (s);
1H NMR (400 MHz, CDCl3): d=7.61 (t, J=7.6 Hz, 2H),
7.55 (d, J=7.6 Hz, 1H), 7.48 (d, J=8.0 Hz, 2H), 7.35 (t, J=
7.2 Hz, 1H), 7.1–7.04 (m, 5H), 7.03 (d, J=8.0 Hz, 2H), 5.52
(d, J=9.6 Hz, 1H), 5.08 (dd, J=9.6, 6.4 Hz, 1H), 3.72 (d,
J=6.4 Hz, 1H), 2.35 (s, 3H), 1.64 (s, 3H), 1.55 (s, 3H);
13C NMR (100 MHz, CD2Cl2): d=184.4, 151.2, 144.1, 140.8,
138.4, 138.3, 134.8, 129.6, 129.4, 128.8, 128.3, 128.1, 127.8,
127.4, 124.5, 82.0, 81.5, 58.1, 55.8, 27.1, 25.1, 21.6; HR-MS:
m/z=431.1553, calcd. for C26H25NO3S: 431.1555.
a strained bicycloACHTNUGRTENUNG[3.1.0]hexane framework. The ste-
reochemical course of this cycloaddition is rational-
ized with a cyclic transition state.[2] The resulting
indanACHTUNGTRENNUNGimine cycloadducts are not readily hydrolyzed
unless external aldehydes are present with the silver
catalyst. The altered stereochemistry in the hydrolysis
is rationalized by a postulated retro-Prins rearrange-
ment,[12] followed by a Prins cyclization.[13]
Acknowledgements
We thank National Science Council and Education Ministry
for financial support of this work.
Experimental Section
Typical Procedure for Synthesis of N-(1,1-Dimethyl-
1,6a-dihydrocyclopropa[a]inden-6ACTHNUTRGNEUNG(1aH)-ylidene)-4-
References
methyl-benzenesulfonamide (3a)
[1] a) H.-U. Reissig, Top. Curr. Chem. 1988, 144, 73;
b) H. N. C. Wong, M. Y. Hon, C. W. Tse, Y. C. Yip, J.
Tango, T. Hudlicky, Chem. Rev. 1989, 89, 165; c) H.-U.
Reissig, R. Zimmer, Chem. Rev. 2003, 103, 1151; d) I. S.
Young, M. A. Kerr, Angew. Chem. 2003, 115, 3131;
Angew. Chem. Int. Ed. 2003, 42, 3023; e) M. Yu, B. L.
Pagenkopf, Tetrahedron 2005, 61, 321.
[2] Selected examples for catalytic cyclopropane/carbonyl
[3+2]cycloadditions, see: a) P. D. Pohlhaus, J. S. John-
son, J. Org. Chem. 2005, 70, 1057; b) P. D. Pohlhaus,
J. S. Johnson, J. Am. Chem. Soc. 2005, 127, 16014;
c) P. D. Pohlhaus, S. D. Sanders, A. T. Parsons, W. Li,
J. S. Johnson, J. Am. Chem. Soc. 2008, 130, 8462;
d) M. J. Campbell, J. S. Johnson, J. Am. Chem. Soc.
2009, 131, 10370; e) S. D. Sanders, A. Ruiz-Olalla, J. S.
Johnson, Chem. Commun. 2009, 5135; f) M. J. Camp-
bell, J. S. Johnson, A. T. Parsons, P. D. Pohlhaus, S. D.
Sanders, J. Org. Chem. 2010, 75, 6317; g) G. Yang, Y.
Shen, K. Li, Y. Sun, Y. Hua, J. Org. Chem. 2011, 76,
229.
To a 1,2-dichloroethane (4 mL) solution of compound 1a
(50 mg, 0.32 mmol) and (3,5-dichloropyridinium-1-yl)tosyl-
ACHTUNGTRENNUNGamide (121.8 mg, 0.38 mmol) was added a 1,2-dichloro-
ethane solution of (2.4 mL) IPrAuNTf2 (13.8 mg,
0.016 mmol); the mixture was heated to 808C for 2.5 h
before it was filtered over a short silica bed. Solvent was
evaporated under reduced pressure; the crude product was
eluted through a silica gel column to afford the indanimine
cycloadduct 3a as yellow oil; yield: 83 mg (0.26 mmol,
80%). IR (neat): n=2981 (m), 1615 (m), 1584 (s), 1319 (s),
1
1155 (s), 854 (s), 673 cmꢀ1 (s); H NMR (400 MHz, CDCl3):
d=7.90 (d, J=8.0 Hz, 2H), 7.72 (d, J=7.6 Hz, 1H), 7.46 (t,
J=7.6 Hz, 1H), 7.34 (d, J=7.6 Hz, 1H), 7.31 (d, J=8.0 Hz,
2H), 7.24 (t, J=7.6 Hz, 1H), 3.31 (d, J=4.4 Hz, 1H), 2.96
(d, J=4.4 Hz, 1H), 2.42 (s, 3H), 1.31 (s, 3H), 0.56 (s, 3H);
13C NMR (100 MHz, CDCl3): d=184.4, 150.2, 143.5, 139.2,
138.0, 134.2, 129.3, 127.4, 127.0, 125.2, 124.3, 49.7, 39.7, 38.6,
27.7, 21.5, 14.8; HR-MS: m/z=325.1142, calcd. for
C19H19NO2S: 325.1136.
[3] The reactions between moncarbonyl-substituted cyclo-
propanes and aldehydes require Lewis acid in excess
proportion (>1.0 equiv.) to give distinct addition prod-
ucts; see selected example: a) C. Brꢁckner, H.-U. Reis-
sig, J. Org. Chem. 1988, 53, 2440; b) H.-U. Reissig, H.
Holzinger, G. Glomsda, Tetrahedron 1989, 45, 3139;
c) C. H. Larsen, B. H. Ridgway, J. T. Shaw, K. A. Woer-
Adv. Synth. Catal. 2013, 355, 1545 – 1552
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
1551

Hsiao-Hua Hung et al.
COMMUNICATIONS
pel, J. Am. Chem. Soc. 1999, 121, 12209; d) Z. Han, S.
Uehira, T. Tsuritani, H. Shinokubo, K. Oshima, Tetra-
hedron 2001, 57, 987.
He, C. Li, L. Zhang, J. Am. Chem. Soc. 2011, 133,
8482; f) A. Mukherjee, R. B. Dateer, R. Chaudhuri, S.
Bhunia, S. N. Karad, R.-S. Liu, J. Am. Chem. Soc. 2011,
133, 15372; g) P. W. Davies, A. Cremonesi, N. Martin,
Chem. Commun. 2011, 47, 379; h) W. He, C. Li, L.
Zhang, J. Am. Chem. Soc. 2011, 133, 1738; i) E. L.
Noey, Y. Luo, L. Zhang, K. N. Houk, J. Am. Chem.
Soc. 2012, 134, 1078.
[4] Gold-catalyzed [3+3] and [4+2]cycloaddtions were re-
ported for special monocarbonyl-substituted cyclopro-
panes bearing a gem-alkyne group; see: a) G. Zhang,
X. Huang, G. Li, L. Zhang, J. Am. Chem. Soc. 2008,
130, 1814; b) Y. Zhang, F. Liu, J. Zhang, Chem. Eur. J.
2010, 16, 6146.
[5] a) M. Schelwies, A. L. Dempwolff, F. Rominger, G.
Helmchen, Angew. Chem. 2007, 119, 5694; Angew.
Chem. Int. Ed. 2007, 46, 5598; b) A. Escribano-Cuesta,
V. Lopez-Carrillo, D. Janssen, A. M. Echavarren,
Chem. Eur. J. 2009, 15, 5646; c) D. B. Huple, R.-S. Liu,
Chem. Commun. 2012, 48, 10975; d) S. A. Gawade, S.
Bhunia, R.-S. Liu, Angew. Chem. 2012, 124, 7955;
Angew. Chem. Int. Ed. 2012, 51, 7835.
[10] Crystallographic data of compounds 4a’ (CCDC
921045), 4h (CCDC 921044), 5a (CCDC 921042), and
7b (CCCD 921043) were deposited at Cambridge Crys-
tallographic Data Center. These data can be obtained
free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
[11] Cyclic transition states were proposed by Johnson for
the stereochemistry of the [3+2]cycloadditions of dicar-
bonylcyclopropane derivatives with aldehydes.[2].
[6] E. Jimꢂnez-NfflÇez, A. M. Echavarren, Chem. Rev.
[12] This retro-Prins process (H!I) has literature prece-
dents; for selected examples, see: a) J. Nokami, K.
Yoshizane, H. Matsuura, S. I. Shimada, J. Am. Chem.
Soc. 1998, 120, 6609; b) T.-P. Loh, Q.-Y. Hu, L.-T. Ma,
J. Am. Chem. Soc. 2001, 123, 2450; c) R. Jasti, C. D.
Anderson, S. D. Rychnovsky, J. Am. Chem. Soc. 2005,
127, 3402; d) R. Jasti, S. D. Rychnovsky, Org. Lett.
2006, 8, 2175.
2008, 108, 3326.
[7] a) D. Vasu, H.-H. Hung, S. Bhunia, S. A. Gawade, A.
Das, R.-S. Liu, Angew. Chem. 2011, 123, 7043; Angew.
Chem. Int. Ed. 2011, 50, 6911; b) D. Qian, J. Zhang,
Chem. Commun. 2011, 47, 11152.
[8] This nitrene reagent was first reported by Zhang; see
C. Li, L. Zhang, Org. Lett. 2011, 13, 1738.
[9] a) L. Ye, L. Cui, G. Zhang, L. Zhang, J. Am. Chem.
Soc. 2010, 132, 3258; b) L. Ye, W. He, L. Zhang, J. Am.
Chem. Soc. 2010, 132, 8550; c) J. Xiao, X. Li, Angew.
Chem. 2011, 123, 7364; Angew. Chem. Int. Ed. 2011, 50,
7226; d) L. Ye, W. He, L. Zhang, Angew. Chem. 2011,
123, 3294; Angew. Chem. Int. Ed. 2011, 50, 3236; e) W.
[13] For selected reviews, see: a) R. D. Adams, S. P. Bhatna-
gar, Synthesis 1977, 661; b) B. B. Snider, in: The Prins
Reaction and Carbonyl Ene Reaction, (Eds.: B. M.
Trost, I. Fleming, C. H. Heathcock), Pergamon Press,
New York, 1991, Vol. 2, pp 526; c) L. E. Overman,
L. D. Pennington, J. Org. Chem. 2003, 68, 7143.
1552
asc.wiley-vch.de
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2013, 355, 1545 – 1552