Organic Letters
Letter
(7) For selected examples of alternative syntheses of chiral allenoates,
see: (a) Li, C.-Y.; Wang, X.-B.; Sun, X.-L.; Tang, Y.; Zheng, J.-C.; Xu,
Z.-H.; Zhou, Y.-G.; Dai, L.-X. J. Am. Chem. Soc. 2007, 129, 1494.
(b) Crouch, I. T.; Neff, R. K.; Frantz, D. E. J. Am. Chem. Soc. 2013,
135, 4970. (c) Wang, Y.; Zhang, W.; Ma, S. J. Am. Chem. Soc. 2013,
135, 11517. (d) Wang, Y.; Zhang, W.; Ma, S. Org. Chem. Front. 2014,
1, 807.
In summary, intramolecular chirality-transfer reaction of
allenoates and alkenes using Lewis acids is disclosed. The use of
chiral catalyst led to improved diastereoselectivity of the
cycloadditions compared to the use of achiral catalysts. Future
investigations aim to extend this method to intermolecular
variants.
(8) Intramolecular [2 + 2] cycloadditions of racemic electron-
deficient allenes and alkenes are known. For reactions of allenoates,
see: (a) Snider, B. B.; Ron, E. J. Org. Chem. 1986, 51, 3643. For
reactions of allenyl sulfones, see: (b) Padwa, A.; Lipka, H.; Watterson,
S. H.; Murphree, S. S. J. Org. Chem. 2003, 68, 6238.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge on the
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S
́ ́
(9) Vakulya, B.; Varga, S.; Csampai, A.; Soos, T. Org. Lett. 2005, 7,
1967.
Crystallographic data for S17 (PDB)
Crystallographic data for S18 (PDB)
Experimental procedures for all compounds and
crystallographic data (PDF)
(10) For selected reviews regarding enantioselective reactions using
thiourea catalysts, see: (a) Schreiner, P. R. Chem. Soc. Rev. 2003, 32,
289. (b) Doyle, A. G.; Jacobsen, E. N. Chem. Rev. 2007, 107, 5713.
(12) [π2s + π2a], [(π2s + π2s) + π2s], or a quasi-pericyclic process with
carbenoid character have all been proposed for related ketene−alkene
[2 + 2] cycloadditions. For a lead reference, see: Wang, X.; Houk, K.
N. J. Am. Chem. Soc. 1990, 112, 1754.
Analytical data for all compounds (PDF)
AUTHOR INFORMATION
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(13) The reaction to prepare 17a/b on a 1.0 mmol scale proceeded
with similar yield and selectivity to that shown in Table 1, entry 3, on a
(14) Reaction of ( )-14 with EtAlCl2 led to formation of ( )-15a/b
in 1:6 E/Z.
(15) Using EtAlCl2 to promote the cycloaddition of ( )-18 provided
( )-19a/b in 76% yield but only 1:1.2 E/Z selectivity.
(16) For representative examples, see: (a) Muller, M.; Mann, A.;
Taddei, M. Tetrahedron Lett. 1993, 34, 3289. (b) Kalek, M.; Stawinski,
J. Adv. Synth. Catal. 2011, 353, 1741. (c) Xin, N.; Ma, S. Eur. J. Org.
Chem. 2012, 2012, 3806.
Corresponding Author
ORCID
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
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Indiana University and the NIH (R01GM110131) are
acknowledged for generous financial support. M.K.B. is a
2017 Novartis Early Career Awardee. We thank Dr. Maren Pink
and Dr. Chun-Hsing Chen (IU) for X-ray crystallography. The
NSF XSEDE program is acknowledged for computational
support.
REFERENCES
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(1) (a) Lee-Ruff, E.; Mladenova, G. Chem. Rev. 2003, 103, 1449.
(b) Namyslo, J. C.; Kaufmann, D. E. Chem. Rev. 2003, 103, 1485.
(c) Hoffmann, N. Chem. Rev. 2008, 108, 1052. (d) Bach, T.; Hehn, J.
P. Angew. Chem., Int. Ed. 2011, 50, 1000. (e) Yoon, T. P. ACS Catal.
2013, 3, 895. (f) Poplata, S.; Troster, A.; Zou, Y.-Q.; Bach, T. Chem.
̈
Rev. 2016, 116, 9748−9815.
(2) For reviews, see: (a) Xu, Y.; Conner, M. L.; Brown, M. K. Angew.
Chem., Int. Ed. 2015, 54, 11918. (b) Fructos, M. R.; Prieto, A.
Tetrahedron 2016, 72, 355.
(3) Conner, M. L.; Xu, Y.; Brown, M. K. J. Am. Chem. Soc. 2015, 137,
3482.
(4) For reviews regarding chirality transfer reactions with allenes, see:
(a) Campolo, D.; Gastaldi, S.; Roussel, C.; Bertrand, M. P.; Nechab,
M. Chem. Soc. Rev. 2013, 42, 8434. (b) Neff, R. K.; Frantz, D. E.
Tetrahedron 2015, 71, 7.
(5) (a) Carreira, E. M.; Hastings, C. A.; Shepard, M. S.; Yerkey, L. A.;
Millward, D. B. J. Am. Chem. Soc. 1994, 116, 6622. (b) Shepard, M. S.;
Carreira, E. M. Tetrahedron 1997, 53, 16253. (c) Shepard, M. S.;
Carreira, E. M. J. Am. Chem. Soc. 1997, 119, 2597. (d) Gulías, M.;
Collado, A.; Trillo, B.; Lop
́
ez, F.; Onate, E.; Esteruelas, M. A.;
̃
Mascarenas, J. L. J. Am. Chem. Soc. 2011, 133, 7660. (e) Brummond, K.
̃
M.; Osbourn, J. M. Beilstein J. Org. Chem. 2011, 7, 601. (f) Noucti, N.
N.; Alexanian, E. J. Angew. Chem., Int. Ed. 2015, 54, 5447.
(6) (a) Liu, H.; Leow, D.; Huang, K.-W.; Tan, C.-H. J. Am. Chem. Soc.
2009, 131, 7212. (b) Inokuma, T.; Furukawa, M.; Uno, T.; Suzuki, Y.;
Yoshida, K.; Yano, Y.; Matsuzaki, K.; Takemoto, Y. Chem. - Eur. J.
2011, 17, 10470.
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