Direct substitution of primary allylic amines with sulfinate salts

Article abstract of DOI:10.1021/ja306407x

The NH₂ group in primary allylic amines was substituted directly by sulfinate salts with excellent regio- and stereoselectivities. In the presence of 0.1 mol % [Pd(allyl)Cl]₂, 0.4 mol % 1,4- bis(diphenylphosphino)butane (dppb), and excess boric acid, a range of α-unbranched primary allylic amines were smoothly substituted with sodium sulfinates in an α-selective fashion to give structurally diverse allylic sulfones in good to excellent yields with exclusive E selectivity. Replacing dppb with 1,1′-bi-2-naphthol (BINOL) allowed unsymmetric α-chiral primary allylic amines to be transformed into the corresponding allylic sulfones in good to excellent yields with excellent retention of ee. Importantly, the reaction complements known asymmetric methods in substrate scope via its unique ability to provide α-chiral allylic sulfones with high optical purity starting from unsymmetric allylic electrophiles.

Full text of DOI:10.1021/ja306407x

Communication
pubs.acs.org/JACS
Direct Substitution of Primary Allylic Amines with Sulfinate Salts
Xue-Song Wu,† Yan Chen,† Man-Bo Li,† Meng-Guang Zhou,† and Shi-Kai Tian*,†,‡
†Joint Laboratory of Green Synthetic Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei,
Anhui 230026, China
‡Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of
Sciences, Shanghai 200032, China
S
* Supporting Information
atom economy. Nevertheless, the reaction requires excess
ABSTRACT: The NH2 group in primary allylic amines
sodium sulfinate and additive (Et3B or TMSCl) and ≥5 mol %
catalyst loading, and it suffers from a narrow substrate scope.12
was substituted directly by sulfinate salts with excellent
regio- and stereoselectivities. In the presence of 0.1 mol %
[Pd(allyl)Cl]2, 0.4 mol % 1,4-bis(diphenylphosphino)-
butane (dppb), and excess boric acid, a range of α-
unbranched primary allylic amines were smoothly
substituted with sodium sulfinates in an α-selective fashion
to give structurally diverse allylic sulfones in good to
excellent yields with exclusive E selectivity. Replacing dppb
with 1,1′-bi-2-naphthol (BINOL) allowed unsymmetric α-
chiral primary allylic amines to be transformed into the
corresponding allylic sulfones in good to excellent yields
with excellent retention of ee. Importantly, the reaction
complements known asymmetric methods in substrate
scope via its unique ability to provide α-chiral allylic
sulfones with high optical purity starting from unsym-
metric allylic electrophiles.
Although a few catalytic asymmetric allylic substitution
reactions with sulfinate salts in the presence of chiral transition-
metal catalysts have been developed, they are limited to
symmetric (α-substituent = γ-substituent) and α-unbranched
allylic electrophiles.15 In addition, the transfer of chirality when
α-chiral allylic electrophiles are used in the synthesis of optically
active allylic sulfones has never been disclosed. In this context,
we sought to explore new methods to prepare α-chiral allylic
sulfones with high optical purity starting from unsymmetric
allylic electrophiles (α-substituent ≠ γ-substituent). Clearly,
controlling both the regio- and stereoselectivity constitutes a
formidable challenge in the asymmetric allylic substitution
reaction of unsymmetric allylic electrophiles.
In the course of exploring the synthetic utilities of sp3 C−N
bond cleavage,16 we recently realized a palladium-catalyzed
cross-coupling reaction of primary allylic amines with organo-
borons wherein the NH2 group serves as an effective leaving
group.17,18 Prompted by this discovery, we envisioned that it
would be possible to develop a direct substitution reaction of
primary allylic amines with sulfinate salts by using inexpensive
boric acid to activate the NH2 group, facilitating cleavage of the
allylic C−N bond by the palladium catalyst. Sulfinate salts were
selected as the sulfonyl nucleophiles because they are more
stable and accessible than sulfinic acids. α-Chiral primary allylic
amines can be easily prepared in large quantities by resolving
the corresponding racemic compounds with inexpensive
tartaric acid,19 and we anticipated that the chiral information
would be efficiently transferred during the preparation of
optically active allylic sulfones.
While no desired reaction was observed between allylic
amine 1a and sulfinate salt 2a in the presence of 0.2 mol %
Pd(PPh3)4 in dioxane at 100 °C (Table 1, entry 1), the addition
of boric acid led to the formation of allylic sulfone 3a in 35%
yield (entry 2). Switching the palladium source to [Pd(allyl)-
Cl]2 (0.1 mol %) improved the yield to 62% (entry 5). The
reaction was significantly affected by the ligand (0.4 mol %),
and the use of 1,4-bis(diphenylphosphino)butane (dppb) as the
ligand enhanced the yield to 92% (entry 7). Replacing boric
acid with a Brønsted acid such as acetic acid or p-
toluenesulfonic acid led to a much lower yield (entries 10
llylic sulfones serve as versatile building blocks in a
A
number of carbon−carbon bond-forming reactions, such
as fragment coupling and Julia olefination, because of activation
of the α-carbon by the sulfonyl group.1 Additionally, certain
allylic sulfones display interesting biological activities, such as
anticancer agents,2 antibacterial agents,3 TSH receptor
antagonists,4 and weed control herbicides.5 Thus, much
attention has been paid to the preparation of allylic sulfones.
While the convergent synthesis of allylic sulfones can be
realized through the coupling of allylic nucleophiles with
sulfonyl electrophiles,6 a more frequently used approach is the
allylic substitution reaction with sulfonyl nucleophiles.7 Both
sulfinate salts and sulfinic acids have been explored as useful
sulfonyl nucleophiles, and in the absence of a catalyst or an
additive, the allylic substitution reaction can proceed with
reactive allylic electrophiles such as allylic halides.8
The use of transition metals, particularly palladium (the
Tsuji−Trost reaction),9 as catalysts dramatically extends the
scope of allylic electrophiles used for the synthesis of allylic
sulfones. Allylic carboxylates,10 carbonates,11 alcohols,12 and
nitro compounds13 undergo substitution reactions with
sulfinate salts to give allylic sulfones with significantly different
reactivities and regioselectivities. When sulfinic acids are
employed as the sulfonyl nucleophiles, the allylic electrophiles
are extended to allylic ethers, sulfides, and secondary and
tertiary amines.14 Notably, the use of an allylic alcohol as the
electrophilic component is extremely attractive with regard to
Received: July 2, 2012
Published: August 28, 2012
© 2012 American Chemical Society
14694
dx.doi.org/10.1021/ja306407x | J. Am. Chem. Soc. 2012, 134, 14694−14697

Journal of the American Chemical Society
Communication
a
Table 1. Optimization of the Reaction Conditions
Table 2. Direct Substitution of α-Unbranched Primary
Allylic Amines with Sodium Sulfinates
a
yield
b
entry
catalyst (mol %)
ligand
none
acid
none
solvent
(%)
yield
b
entry
1, R1, R2, R3
1a, Ph, H, H
2, R
2a, Ph
3
(%)
1
2
Pd(PPh3)4 (0.2)
Pd(PPh3)4 (0.2)
Pd2(dba)3 (0.1)
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
diglyme
toluene
DMF
0
none
none
B(OH)3
B(OH)3
B(OH)3
B(OH)3
B(OH)3
B(OH)3
B(OH)3
B(OH)3
HOAc
35
21
27
62
42
92
76
81
39
trace
77
9
1
2
3
4
3a
3b
3c
3d
3e
3f
92
90
82
67
79
84
70
80
76
79
83
84
94
94
86
64
80
75
92
87
3
1b, 4-MeOC6H4, H, H
1c, 4-ClC6H4, H, H
1d, 2-MeOC6H4, H, H
1e, 2-O2NC6H4, H, H
1f, 2-furyl, H, H
2a, Ph
2a, Ph
2a, Ph
2a, Ph
2a, Ph
4
Pd(PPh3)2Cl2 (0.2) none
[Pd(allyl)Cl]2 (0.1) none
[Pd(allyl)Cl]2 (0.1) PPh3
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) TMEDA
[Pd(allyl)Cl]2 (0.1) BINOL
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
[Pd(allyl)Cl]2 (0.1) dppb
5
c
6
5
7
6
7
8
9
8
1g, (E)-MeCHCH, H, H 2a, Ph
3g
3h
3i
9
1h, n-hexyl, H, H
1i, cyclohexyl, H, H
1j, H, H, H
2a, Ph
10
11
12
13
14
15
16
2a, Ph
d
TsOH
10
2a, Ph
3j
B(OH)3
B(OH)3
B(OH)3
B(OH)3
B(OH)3
B(OH)3
11
12
13
14
15
1k, Ph, Me, H
1l, H, H, Ph
2a, Ph
3k
3a
3l
2a, Ph
55
50
11
82
1a, Ph, H, H
1a, Ph, H, H
1a, Ph, H, H
1a, Ph, H, H
1a, Ph, H, H
1a, Ph, H, H
1a, Ph, H, H
1a, Ph, H, H
2b, 4-MeOC6H4
2c, 4-MeC6H4
2d, 4-ClC6H4
2f, 1-naphthyl
2g, 2-naphthyl
2h, Me
DMSO
water
3m
3n
3o
3p
3q
3r
3s
c
c
17
dioxane
16
a
Reaction conditions: amine 1a (0.50 mmol), sulfinate 2a (0.60
mmol), catalyst (0.1 or 0.2 mol %), ligand (if any, 0.4 mol %), acid (if
17
18
19
20
b
c
any, 2.0 mmol), solvent (0.50 mL), 100 °C, 4 h. Isolated yields. The
2i, n-C16H33
2j, PhCH2
reaction was run at 80 °C.
a
Reaction conditions: amine 1 (0.50 mmol), sulfinate 2 (0.60 mmol),
[Pd(allyl)Cl]2 (0.1 mol %), dppb (0.4 mol %), B(OH)3 (2.0 mmol),
and 11). In addition, the yield decreased significantly when
common solvents other than dioxane were used (entries 12−
16) or the reaction was performed at a lower temperature
(entry 17).
b
c
dioxane (0.50 mL), 100 °C, 4 h. Isolated yields. The reaction was
run for 12 h. The reaction was run in a sealed tube.
d
In the presence of 0.1 mol % [Pd(allyl)Cl]2, 0.4 mol % dppb,
and excess boric acid, a range of α-unbranched primary allylic
amines were smoothly substituted with various sodium
sulfinates in an α-selective fashion to give the corresponding
allylic sulfones in good to excellent yields (Table 2). Notably,
the β- and γ-positions of the allylic amines could bear various
substituents such as aryl, heteroaryl, alkenyl, or alkyl groups.
While the alkene geometry was retained in reactions with (E)-
allylic amines (entries 1−9, 11, and 13−20), it was completely
inverted in a reaction with a (Z)-allylic amine (entry 12). The
complete Z-to-E isomerization could be attributable to the
generation of a π-allylpalladium intermediate from the
palladium catalyst and the allylic amine (see below), with the
reaction preferring to give an (E)-allylic sulfone under
thermodynamic conditions.
The generation of a π-allylpalladium intermediate could
provide a rationale for the γ-selectivity observed in the reaction
with α-substituted allylic amines. For example, the reaction of
α-phenyl allylamine (4) with sulfinate 2a gave allylic sulfone 3a
in 91% yield with exclusive E selectivity (eq 1). The γ-selectivity
probably arises from maximizing conjugation and minimizing
steric hindrance prior to sulfinate attack on the π-allylpalladium
intermediate (see below).
converted to the desired product, allyl sulfone 3j, in a slightly
lower but still good yield relative to that for allylamine (1j)
(Table 2, entry 10).
We envisioned that the use of α-chiral primary allylic amines
would enable the generation of chiral allylic sulfones by a
chirality transfer mechanism. Thus, the aforementioned
conditions were applied to chiral amine 7a, whose optical
purity was 99% ee. Whereas the reaction proceeded in an α-
selective fashion to give chiral sulfone 8a in 97% yield with
exclusive E selectivity, the ee decreased to 82% (Table 3, entry
1). To achieve an effective transfer of chirality, we surveyed a
few ligands that significantly affected the stereoselectivity. To
our delight, the use of racemic BINOL as the ligand
dramatically reduced the deterioration of the ee and led to
the formation of sulfone 8a with 96% ee (entry 4). (R)-BINOL
was examined for comparison, and the reaction gave the same
stereoselectivity.20 Moreover, a lower ee and yield were
obtained when BINOL was replaced with one of its derivatives,
ethylene glycol, or phenol (entries 5−8).
In the presence of 0.1 mol % [Pd(allyl)Cl]2, 0.4 mol %
BINOL, and excess boric acid, a range of enantioenriched α-
chiral primary allylic amines (R1 ≠ R3) were smoothly
substituted with sodium sulfinates in an α-selective fashion to
give various α-chiral allylic sulfones in good to excellent yields
Diallyamine (5) and triallylamine (6) were also examined
(eq 2), and to our delight, each of their allyl groups could be
14695
dx.doi.org/10.1021/ja306407x | J. Am. Chem. Soc. 2012, 134, 14694−14697

Journal of the American Chemical Society
Communication
a
Table 3. Survey of Ligands
b
c
b
c
entry
1
ligand
dppb
ee (%)
yield (%)
entry
ligand
ee (%)
yield (%)
d
82
91
84
96
97
96
87
93
5
3,3′-Ph2-BINOL
6,6′-Br2-BINOL
HOCH2CH2OH
PhOH
94
95
95
93
45
63
86
90
d
d
2
BINAP
TMEDA
BINOL
6
3
7
8
d
4
a
Reaction conditions: amine 7a (0.50 mmol), sulfinate 2c (0.60 mmol), [Pd(allyl)Cl]2 (0.1 mol %), ligand (0.4 mol %), B(OH)3 (2.0 mmol),
b
c
d
dioxane (0.50 mL), 100 °C, 4 h. Determined by HPLC analysis on a chiral stationary phase. Isolated yields. The racemic ligand was used.
with excellent retention of ee (Table 4).21 Importantly, the
Scheme 1. Proposed Reaction Pathways
reaction complements known asymmetric methods15 in regard
Table 4. Direct Substitution of α-Chiral Primary Allylic
a
Amines with Sodium Sulfinates
b
ee (%)
yield
c
entry
1
7, R1, R2, R3
2, R
2c, 4-
8
7
8
(%)
7a, Ph, H, Me
8a
99
96
93
MeC6H4
2c, 4-
MeC6H4
2c, 4-
MeC6H4
2c, 4-
MeC6H4
2c, 4-
MeC6H4
2a, Ph
2
3
4
5
7b, 2-naphthyl, H,
8b
8c
8d
8e
8f
93
99
98
96
92
98
97
95
86
82
92
95
Me
7c, cyclohexyl, H,
Me
7d, Ph, Me, Me
7e, Ph, H, Et
6
7
8
9
7a, Ph, H, Me
7a, Ph, H, Me
7a, Ph, H, Me
7a, Ph, H, Me
99
99
99
99
94
96
92
95
93
90
78
88
2d, 4-ClC6H4 8g
2h, Me
8h
8i
2j, PhCH2
a
Reaction conditions: amine 7 (0.50 mmol), sulfinate 2 (0.60 mmol),
sulfinate 2 on [Pd(allyl)Cl]2 leads to the formation of allyl
sulfone 9 and the palladium(0) catalyst (PdLn). The NH2
group in chiral amine 7 is activated by boric acid, and the allylic
C−N bond is cleaved by the palladium(0) catalyst with
inversion of configuration to give π-allylpalladium 11a.17 When
BINOL is used as the ligand, the allylic carbon of complex 11a
is attacked by sulfinate 2 with inversion of configuration to give
chiral sulfone 8 and regenerate the palladium(0) catalyst (path
a). Alternatively, the palladium atom of complex 11a is attacked
by sulfinate 2 to form palladium-S-sulfinate 13a,22 which
undergoes reductive elimination to give the minor enantiomer
ent-8 (path b). The regioselectivity is determined by the steric
and electronic properties of the R1 and R3 groups in complexes
11a and 13a. If R1 = R3, the reaction loses optical purity
completely because of symmetry. It is noteworthy that
racemization of complex 11a takes place when a phosphine is
used as the ligand,9 and consequently, a portion of chiral amine
7 is transformed into chiral sulfone ent-8 (path c).
[Pd(allyl)Cl]2 (0.1 mol%), BINOL (0.4 mol%), B(OH)3 (2.0 mmol),
dioxane (0.50 mL), 100 °C, 4 h. Determined by HPLC analysis on a
chiral stationary phase. Isolated yields.
b
c
to substrate scope as a result of its unique ability to provide α-
chiral allylic sulfones with high optical purity starting from
unsymmetric allylic electrophiles.
In contrast, when the putative π-allylpalladium intermediate
was symmetric, the product was observed as a racemic mixture,
but still with excellent yield (eq 3). Taken together, this
stereoerosion, the Z-to-E isomerization (Table 2, entry 12), and
the γ-selectivity with an α-substituted allylamine (eq 1)
substantially support the intermediacy of a π-allylpalladium
species.
According to our results and the general mechanism of the
Tsuji−Trost reaction,9 we propose the following reaction
pathways for the substitution reaction of α-chiral primary allylic
amines with sulfinate salts (Scheme 1). Nucleophilic attack of
In summary, we have developed for the first time a highly
efficient direct substitution reaction of primary allylic amines
with sulfinate salts. In the presence of 0.1 mol % [Pd(allyl)Cl]2,
0.4 mol % dppb, and excess boric acid, a range of α-unbranched
primary allylic amines are smoothly substituted with sodium
sulfinates in an α-selective fashion to give structurally diverse
allylic sulfones in good to excellent yields with exclusive E
14696
dx.doi.org/10.1021/ja306407x | J. Am. Chem. Soc. 2012, 134, 14694−14697

Journal of the American Chemical Society
Communication
(10) For examples, see: (a) Inomata, K.; Yamamoto, T.; Kotake, H.
Chem. Lett. 1981, 1357. (b) Felpin, F.-X.; Landais, Y. J. Org. Chem.
2005, 70, 6441. (c) Liao, M.-C.; Duan, X.-H.; Liang, Y.-M. Tetrahedron
Lett. 2005, 46, 3469.
(11) For examples, see: (a) Safi, M.; Sinou, D. Tetrahedron Lett.
1991, 32, 2025. (b) Jegelka, M.; Plietker, B. Org. Lett. 2009, 11, 3462.
(12) (a) Chandrasekhar, S.; Jagadeshwar, V.; Saritha, B.; Narsihmulu,
C. J. Org. Chem. 2005, 70, 6506. (b) Reddy, M. A.; Reddy, P. S.;
Sreedhar, B. Adv. Synth. Catal. 2010, 352, 1861.
(13) (a) Ono, N.; Hamamoto, I.; Kawai, T.; Kaji, A.; Tamura, R.;
Kakihana, M. Bull. Chem. Soc. Jpn. 1986, 59, 405. (b) Tamura, R.; Kai,
Y.; Kakihana, M.; Hayashi, K.; Tsuji, M.; Nakamura, T.; Oda, D. J. Org.
Chem. 1986, 51, 4375.
(14) Kunakova, R. V.; Gaisin, R. L.; Sirazova, M. M.; Dzhemilev, U.
M. Izv. Akad. Nauk SSSR, Ser. Khim. 1983, 32, 157; Bull. Acad. Sci.
USSR, Div. Chem. Sci. (Engl. Transl.) 1983, 32, 133.
selectivity. Replacing dppb with BINOL allows α-chiral primary
allylic amines to be transformed into the corresponding allylic
sulfones in good to excellent yields with excellent retention of
ee. Importantly, the reaction complements known asymmetric
methods in substrate scope via its unique ability to provide α-
chiral allylic sulfones with high optical purity starting from
unsymmetric allylic electrophiles.
ASSOCIATED CONTENT
* Supporting Information
■
S
General information, experimental procedures, characterization
data, and copies of 1H and 13C NMR spectra and HPLC traces.
This material is available free of charge via the Internet at
http://pubs.acs.org.
(15) (a) Hiroi, K.; Makino, K. Chem. Lett. 1986, 617. (b) Hirasawa,
K.; Kawamata, M.; Hiroi, K. Yakugaku Zasshi 1994, 114, 111.
(c) Eicheimann, H.; Gais, H.-J. Tetrahedron: Asymmetry 1995, 6, 643.
(d) Trost, B. M.; Organ, M. G.; O’Doherty, G. A. J. Am. Chem. Soc.
1995, 117, 9662. (e) Trost, B. M.; Krische, M. J.; Radinov, R.; Zanoni,
G. J. Am. Chem. Soc. 1996, 118, 6297. (f) Gais, H.-J.; Spalthoff, N.;
Jagusch, T.; Frank, M.; Raabe, G. Tetrahedron Lett. 2000, 41, 3809.
(g) Gais, H.-J.; Jagusch, T.; Spalthoff, N.; Gerhards, F.; Frank, M.;
Raabe, G. Chem.Eur. J. 2003, 9, 4202. (h) Ueda, M.; Hartwig, J. F.
Org. Lett. 2010, 12, 92.
(16) (a) Liu, C.-R.; Li, M.-B.; Yang, C.-F.; Tian, S.-K. Chem.Eur. J.
2009, 15, 793. (b) Liu, C.-R.; Yang, F.-L.; Jin, Y.-Z.; Ma, X.-T.; Cheng,
D.-J.; Li, N.; Tian, S.-K. Org. Lett. 2010, 12, 3832. (c) Yang, B.-L.;
Tian, S.-K. Chem. Commun. 2010, 46, 6180. (d) Yang, C.-F.; Wang, J.-
Y.; Tian, S.-K. Chem. Commun. 2011, 47, 8343. (e) Li, M.-B.; Tang, X.-
L.; Tian, S.-K. Adv. Synth. Catal. 2011, 353, 1980. (f) Weng, Z.-T.; Li,
Y.; Tian, S.-K. J. Org. Chem. 2011, 76, 8095. (g) Wu, X.-S.; Tian, S.-K.
Chem. Commun. 2012, 48, 898.
AUTHOR INFORMATION
Corresponding Author
tiansk@ustc.edu.cn
■
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are grateful for the financial support from the National
Natural Science Foundation of China (21172206 and
20972147), the National Basic Research Program of China
(2010CB833300), and the Program for Changjiang Scholars
and Innovative Research Team in University (IRT1189).
REFERENCES
■
(1) For reviews, see: (a) El-Awa, A.; Noshi, M. N.; du Jourdin, X. M.;
Fuchs, P. L. Chem. Rev. 2009, 109, 2315. (b) Plesniak, K.; Zarecki, A.;
Wicha, J. Top. Curr. Chem. 2007, 275, 163. (c) Hassner, A.; Ghera, E.;
Yechezkel, T.; Kleiman, V.; Balasubramanian, T.; Ostercamp, D. Pure
Appl. Chem. 2000, 72, 1671. (d) Prilezhaeva, E. N. Russ. Chem. Rev.
2000, 69, 367. (e) Simpkins, N. S. Sulfones in Organic Synthesis;
Pergamon Press: New York, 1993.
(2) Neamati, N.; Kabalka, G. W.; Venkataiah, B.; Dayam, R. W.O.
Patent 081966, 2007.
(3) Reck, F.; Zhou, F.; Girardot, M.; Kern, G.; Eyermann, C. J.;
Hales, N. J.; Ramsay, R. R.; Gravestock, M. B. J. Med. Chem. 2005, 48,
499.
(4) Gershengorn, M. C.; Neumann, S.; Thomas, C. J.; Jaeschke, H.;
Moore, S.; Krause, G.; Raaka, B.; Paschke, R.; Kleinau, G. U.S. Patent
0,203,716, 2009.
(5) Muehlebach, M.; Lutz, W.; Wenger, J.; Finney, J.; Mathews, C. J.;
Fawke, D. W.O. Patent 110308, 2008.
(6) For examples, see: (a) Frye, L. L.; Sullivan, E. L.; Cusack, K. P.;
Funaro, J. M. J. Org. Chem. 1992, 57, 697. (b) Sun, P.; Wang, L.;
Zhang, Y. Tetrahedron Lett. 1997, 38, 5549. (c) Steensma, R. W.;
Galabi, S.; Tagat, J. R.; McCombie, S. W. Tetrahedron Lett. 2001, 42,
2281.
(7) For reviews, see: (a) Procter, D. J. J. Chem. Soc., Perkin Trans. 1
2001, 335. (b) Solladie, G. In Comprehensive Organic Synthesis; Trost,
B. M., Fleming, I., Eds.; Pergamon Press: Oxford, U.K., 1991; Vol. 6,
pp 133.
(17) Li, M.-B.; Wang, Y.; Tian, S.-K. Angew. Chem., Int. Ed. 2012, 51,
2968.
(18) For the use of secondary and tertiary allylic amines as allylic
electrophiles, see: (a) Trost, B. M.; Keinan, E. J. Org. Chem. 1980, 45,
2741. (b) Murahashi, S.-I.; Makabe, Y.; Kunita, K. J. Org. Chem. 1988,
́
53, 4489. (c) Garro-Helion, F.; Merzouk, A.; Guibe, F. J. Org. Chem.
1993, 58, 6109. (d) Murahashi, S.-I.; Imada, Y.; Nishimura, K.
Tetrahedron 1994, 50, 453. (e) Trost, B. M.; Spagnol, M. D. J. Chem.
Soc., Perkin Trans. 1 1995, 2083. (f) Bricout, H.; Carpentier, J.-F.;
Mortreux, A. Chem. Commun. 1997, 1393. (g) Pawlas, J.; Nakao, Y.;
Kawatsura, M.; Hartwig, J. F. J. Am. Chem. Soc. 2002, 124, 3669.
(h) Watson, I. D. G.; Yudin, A. K. J. Am. Chem. Soc. 2005, 127, 17516.
(i) Mukherjee, S.; List, B. J. Am. Chem. Soc. 2007, 129, 11336.
(j) Dubovyk, I.; Pichugin, D.; Yudin, A. K. Angew. Chem., Int. Ed. 2011,
50, 5924. (k) Zhao, X.; Liu, D.; Guo, H.; Liu, Y.; Zhang, W. J. Am.
Chem. Soc. 2011, 133, 19354.
(19) Schenck, T. G.; Bosnich, B. J. Am. Chem. Soc. 1985, 107, 2058.
(20) When racemic 7a was used as the electrophile, the reaction gave
racemic 8a. This result indicates that the stereochemistry is controlled
by the substrate.
(21) No alkylation reaction was observed when CH2(CO2Et)2,
CH2(COPh)2, or indole was used as the nucleophile.
(22) For related examples, see: (a) Hung, T.; Jolly, P. W.; Wilke, G. J.
Organomet. Chem. 1980, 190, C5. (b) Dzhemilev, U. M.; Kunakova, R.
V.; Gaisin, R. L.; Valyamova, F. G.; Tolstikov, G. A. Izv. Akad. Nauk
SSSR, Ser. Khim. 1990, 39, 1146; Bull. Acad. Sci. USSR, Div. Chem. Sci.
(Engl. Transl.) 1990, 39, 1030.
(8) Using in situ activation by the sulfonylating agent extends scope
of the allylic electrophiles to include allylic alcohols and N-allylic
sulfonamides. See: (a) Reddy, L. R.; Hu, B.; Prashad, M.; Prasad, K.
Angew. Chem., Int. Ed. 2009, 48, 172. (b) Li, H.-H.; Dong, D.-J.; Jin, Y.-
H.; Tian, S.-K. J. Org. Chem. 2009, 74, 9501. (c) Liu, C.-R.; Li, M.-B.;
Cheng, D.-J.; Yang, C.-F.; Tian, S.-K. Org. Lett. 2009, 11, 2543.
(9) For reviews, see: (a) Tsuji, J. Acc. Chem. Res. 1969, 2, 144.
(b) Trost, B. M. Tetrahedron 1977, 33, 2615. (c) Trost, B. M.; Van
Vranken, D. L. Chem. Rev. 1996, 96, 395. (d) Trost, B. M.; Crawley,
M. L. Chem. Rev. 2003, 103, 2921.
14697
dx.doi.org/10.1021/ja306407x | J. Am. Chem. Soc. 2012, 134, 14694−14697