Communication
ChemComm
J. Am. Chem. Soc., 1985, 107, 2806; (c) Y. Apeloig, R. Biton and A. Abu-
Freih, J. Am. Chem. Soc., 1993, 115, 2522; (d) M. A. Brook, Silicon in
Organic, Organometallic and Polymer Chemistry, Wiley, New York, 1st
edn, 2000, p. 480, and references cited therein.
active a-hydroxy-a-alkenylsilanes. The reaction was effectively
promoted by the catalytic use of TMSOTf and provide the
vinylsilane-tethered tetrahydronaphthalenes having a high
optical purity (up to 98% ee). To the best of our knowledge,
the intramolecular Friedel–Crafts cyclization reaction of allylic
alcohols under acid-catalyzed conditions with extremely high
chirality transfer has not been reported.18 During the reaction
conditions, the 1,3-rearrangement of the a-hydroxy-a-alkenylsilanes
also occurred to give the highly optically active g-hydroxyvinyl-
silanes (499% ee).11,17 The silyl group attached to a chiral carbon
in the starting materials plays a crucial role in the efficient
chirality transfer due to the destabilization of the adjacent carbo-
cation (a-silyl cation) more than an alkyl or aryl group.7 Further
studies with regard to the synthetic applications toward biologi-
cally important compounds via the use of this silicon-assisted
chirality-transferring reaction are in progress in our laboratories.
We are grateful to the Japan Society of the Promotion of
Science (JSPS KAKENHI Grant Numbers 16201045 and 17K05935)
for supporting this work.
8 For the intramolecular Friedel–Crafts cyclization reactions of allyl
alcohols and their derivatives, see the following reports and references
cited therein: (a) S. Ma and J. Shang, Tetrahedron Lett., 2002, 43, 3435;
(b) S. Ma and J. Shang, Tetrahedron, 2003, 59, 6273; (c) M. Bandini,
A. Melloni, F. Piccinelli, R. Sinisi, S. Tommasi and A. Umani-Ronchi,
J. Am. Chem. Soc., 2006, 128, 1424; (d) K. Namba, H. Yamamoto,
I. Sasaki, K. Mori, H. Imagawa and M. Nishizawa, Org. Lett., 2009,
10, 1767; (e) M. Bandini and A. Eichholzer, Angew. Chem., Int. Ed., 2009,
48, 9533; ( f ) J. A. McCubbin, H. Hosseini and O. V. Krokhin, J. Org.
Chem., 2010, 75, 959; (g) Q.-F. Wu, H. He, W.-B. Liu and S.-L. You, J. Am.
Chem. Soc., 2010, 132, 11418; (h) H. Zheng, S. Ghanbari, S. Nakamura
and D. G. Hall, Angew. Chem., Int. Ed., 2012, 51, 6187; (i) F.-Z. Zhang,
Y. Tian, G.-X. Li and J. Qu, J. Org. Chem., 2015, 80, 1107; ( j) J. Li, X. Tan,
X. Mu, J. Gong and Z. Yang, Chin. J. Chem., 2017, 35, 562; For general
reviews on asymmetric catalytic Friedel–Crafts alkylation reactions, see
the following reports and the references cited therein: (k) T. B. Poulsen
and K. A. Jorgensen, Chem. Rev., 2008, 108, 2903; (l) Catalytic Asym-
metric Friedel–Crafts Alkylations, ed. M. Bandini and A. Umani-Ronchi,
Wiley-VCH, Weinheim, 2009.
9 The ee of 4a was determined by the chiral HPLC analysis (DAICEL,
CHIRALCEL OD-H, 0.46 cm ꢃ 25 cm, n-hexane = 100, 0.5 mL minꢁ1
,
0 1C, 254 nm). The absolute configuration of 4a was determined by
converting it into the known compound, see ESI†.
Conflicts of interest
10 The ee of 7a was determined by the chiral HPLC analysis (DAICEL,
CHIRALPAK AD-H, 0.46 cm ꢃ 25 cm, n-hexane/EtOH = 50/1,
0.5 mL minꢁ1, 25 1C, 254 nm). The absolute configuration of 7a was
determined by the modified Mosher method: I. Ohtani, T. Kusumi,
H. Kashman and H. Kakisawa, J. Am. Chem. Soc., 1991, 113, 4092.
11 The acid-catalyzed 1,3-rearrangement of allylic alcohols with high
transfer of chirality (499%) is unknown.
There are no conflicts to declare.
Notes and references
1 (a) N. Kawai, J.-M. Lagrange, M. Ohmi and J. Uenishi, J. Org. Chem.,
2006, 71, 4530; (b) Y. S. Vikhe, S. M. Hande, N. Kawai and J. Uenishi,
J. Org. Chem., 2009, 74, 5174.
12 The ee of 10 was determined by the chiral HPLC analysis (DAICEL,
CHIRALCEL OD-H, 0.46 cm ꢃ 25 cm, n-hexane = 100, 0.1 mL minꢁ1
,
0 1C, 265 nm). The absolute configuration of the resulting 10 was
not determined.
2 A. Aponick and B. Biannic, Org. Lett., 2011, 13, 1330.
3 (a) N. Kawai, R. Abe and J. Uenishi, Tetrahedron Lett., 2009, 50, 6580;
(b) N. Kawai, R. Abe, M. Matsuda and J. Uenishi, J. Org. Chem., 2011,
76, 2102.
13 The Ph-substituted 11 (499% ee) was prepared by the optical
resolution of (ꢀ)-11 by HPLC using a chital stationary phase column
(see ESI†).
14 Treatment of the isolated 14 and 16 under the reaction conditions
{TMSOTf (1.0 equiv.), 3 Å MS, CH2Cl2 ꢁ78 1C, 21 h} resulted in the
recovery of the starting materials.
15 Enantio-enriched a-hydroxy-a-alkenylsilanes 3d–f were prepared via
enantioselective hydrogenation of corresponding silyl ketones, see
ESI†.
16 The reaction of 3c (68% ee) using TMSOTf (1.0 equiv.) gave 4c (53%,
27% ee).
4 C. Morrill and R. H. Grubbs, J. Am. Chem. Soc., 2005, 127, 2842.
5 (a) K. Sakaguchi, M. Fujita and Y. Ohfune, Tetrahedron Lett., 1998,
39, 4313; (b) K. Sakaguchi, T. Yamada and Y. Ohfune, Tetrahedron
Lett., 2005, 46, 5009; (c) K. Sakaguchi, T. Okada, T. Yamada and
Y. Ohfune, Tetrahedron Lett., 2007, 48, 3925; (d) K. Sakaguchi,
T. Okada, T. Shinada and Y. Ohfune, Tetrahedron Lett., 2008,
49, 25; (e) M. Higashino, N. Ikeda, T. Shinada, K. Sakaguchi and
Y. Ohfune, Tetrahedron Lett., 2011, 52, 422.
6 K. Sakaguchi, M. Higashino and Y. Ohfune, Tetrahedron, 2003, 59, 6647.
7 According to the MP2/6-31G*//3-21G calculations, the carbocation a
to the SiH3 group (a-silyl cation) is 18.3 kcal molꢁ1 less stable than
the corresponding carbocation a to a methyl group: (a) P. J. Stang,
M. Ladika, Y. Apeloig, A. Stanger, M. D. Schiavelli and M. R. Hughey,
J. Am. Chem. Soc., 1982, 104, 6852; (b) Y. Apeloig and A. Stanger,
17 A. I. Kim, K. L. Kimmel, A. Romero, J. H. Smitrovich and K. A. Woerpel,
J. Org. Chem., 2007, 72, 6595.
18 The copper(I)-mediated anti-SN20 allylic substitution of a-acyloxy-
a-alkenylsilane with high transfer of chirality was reported. S. Perrone
and P. Knochel, Org. Lett., 2007, 9, 1041.
Chem. Commun.
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