Organic Letters
Letter
Ber. 1981, 114, 3751. (c) Battaglia, A.; Barbaro, G.; Giorgianni, P.;
Foresti, E.; Sabatino, P.; Dondoni, A. J. Org. Chem. 1985, 50, 5368.
(d) Inoue, S.; Suzuki, O.; Sato, K. J. Chem. Soc., Chem. Commun. 1985,
1773. (e) Moderhack, D.; Stolz, K. Chem. Ber. 1986, 119, 3411.
(f) Quast, H.; Bieber, L.; Regnat, D. Chem. Ber. 1990, 123, 1739.
(g) Katagiri, T.; Handa, M.; Asano, H.; Asanuma, T.; Mori, T.; Jukurogi,
T.; Uneyama, K. J. Fluorine Chem. 2009, 130, 714. (h) Jin, X.; Willeke,
M.; Lucchesi, R.; Daniliuc, C.-G.; Froehlich, R.; Wibbeling, B.; Uhl, W.;
Wuerthwein, E.-U. J. Org. Chem. 2015, 80, 6062.
(7) De Corte, B.; Denis, J. M.; De Kimpe, N. J. Org. Chem. 1987, 52,
1147.
(8) Surmont, R.; De Corte, B.; De Kimpe, N. Tetrahedron Lett. 2009,
50, 3877.
(9) (a) De Kimpe, N.; Verhe, R.; De Buyck, L.; Chys, J.; Schamp, N. J.
Org. Chem. 1978, 43, 2670. (b) De Kimpe, N.; Verhe, R.; De Buyck, L.;
Schamp, N. Org. Prep. Proced. Int. 1982, 14, 213.
(10) (a) Stevens, C. L.; Gasser, R. J. J. Am. Chem. Soc. 1957, 79, 6057.
(b) Motoyoshiya, J.; Teranishi, A.; Mikoshiba, R.; Yamamoto, I.; Gotoh,
H.; Enda, J.; Ohshiro, Y.; Agawa, T. J. Org. Chem. 1980, 45, 5385.
(c) Sung, K.; Chen, F.-L.; Huang, P.-M.; Chiang, S.-M. Tetrahedron
2006, 62, 171. (d) Erb, J.; Strull, J.; Miller, D.; He, J.; Lectka, T. Org. Lett.
2012, 14, 2191.
borate complex was present (II or III), but the [(BINAP)Pd-
(Allyl)]+ complex was the only Pd species observable by mass
spectrometry at the end of the reaction (Scheme 6). The
preference for electron-neutral substituents and the observation
that TFA was a very selective additive could suggest that the
reaction proceeds directly from II to IV. Such a scenario would
locate the anion very remote from the aromatic group and form a
labile carbamic acid derivative when TFA is used.
In conclusion, we have developed a mild and functional-group-
tolerant approach to ketenimines that circumvents many of the
issues encountered in other methods. The ketenimines can be
hydrolyzed to the corresponding secondary amides, providing a
new route that is especially efficient for non-nucleophilic,
electron-poor anilines. We have also demonstrated other
derivatizations of the ketenimine intermediates, reacting them
with sulfur ylides and imines. Mechanistic studies provided
evidence of a dissociative outer-sphere mechanism. These studies
also suggested that reductive alkylation is rate-limiting.
Extensions of this reaction are currently being explored.
(11) Shimizu, M.; Gama, Y.; Takagi, T.; Shibakami, M.; Shibuya, I.
Synthesis 2000, 2000, 517.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge on the
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(12) Firl, J.; Schink, K.; Kosbahn, W. Chem. Lett. 1981, 10, 527.
(13) (a) Newman, M. S.; Fukunaga, T.; Miwa, T. J. Am. Chem. Soc.
1960, 82, 873. (b) Clarke, L. F.; Hegarty, A. F. J. Org. Chem. 1992, 57,
1940. (c) Russell, G. A.; Chen, P.; Yao, C.-F.; Kim, B. H. J. Am. Chem.
Soc. 1995, 117, 5967.
Procedures, characterization, and NMR spectra (PDF)
(14) For a review of silyl ketenimines, see: Denmark, S. E.; Wilson, T.
W. Angew. Chem., Int. Ed. 2012, 51, 9980.
AUTHOR INFORMATION
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(15) (a) Chen, J.; Cook, M. J. Org. Lett. 2013, 15, 1088. For an
analogous report published similtaneously, see: (b) Montgomery, T. D.;
Zhu, Y.; Kagawa, N.; Rawal, V. H. Org. Lett. 2013, 15, 1140.
(16) (a) Mulder, J. A.; Kurtz, K. C. M.; Hsung, R. P. Synlett 2003, 1379.
(b) Evano, G.; Coste, A.; Jouvin, K. Angew. Chem., Int. Ed. 2010, 49,
2840. (c) DeKorver, K. A.; Li, H.; Lohse, A. G.; Hayashi, R.; Lu, Z.;
Zhang, Y.; Hsung, R. P. Chem. Rev. 2010, 110, 5064. (d) Evano, G.;
Jouvin, K.; Coste, A. Synthesis 2013, 45, 17. (e) Wang, X.-N.; Yeom, H.-
S.; Fang, L.-C.; He, S.; Ma, Z.-X.; Kedrowski, B. L.; Hsung, R. P. Acc.
Chem. Res. 2014, 47, 560. (f) Mansfield, S. J.; Campbell, C. D.; Jones, M.
W.; Anderson, E. A. Chem. Commun. 2015, 51, 3316.
(17) (a) Zhang, Y.; DeKorver, K. A.; Lohse, A. G.; Zhang, Y.-S.; Huang,
J.; Hsung, R. P. Org. Lett. 2009, 11, 899. (b) DeKorver, K. A.; Hsung, R.
P.; Lohse, A. G.; Zhang, Y. Org. Lett. 2010, 12, 1840. (c) DeKorver, K.
A.; Johnson, W. L.; Zhang, Y.; Hsung, R. P.; Dai, H.; Deng, J.; Lohse, A.
G.; Zhang, Y.-S. J. Org. Chem. 2011, 76, 5092.
(18) (a) DeKorver, K. A.; Wang, X.-N.; Walton, M. C.; Hsung, R. P.
Org. Lett. 2012, 14, 1768. (b) DeKorver, K. A.; Hsung, R. P.; Song, W.-
Z.; Wang, X.-N.; Walton, M. C. Org. Lett. 2012, 14, 3214. (c) Wang, X.-
N.; Winston-McPherson, G. N.; Walton, M. C.; Zhang, Y.; Hsung, R. P.;
DeKorver, K. A. J. Org. Chem. 2013, 78, 6233.
(19) For a review of decarboxyaltive allylations and benzylations, see:
Weaver, J. D.; Recio, A., III; Grenning, A. J.; Tunge, J. A. Chem. Rev.
2011, 111, 1846.
Corresponding Author
ORCID
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
We thank Queen’s University Belfast, Montana State University,
and DEL (studentship to J.R.A.) for support.
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REFERENCES
■
(1) For reviews of ketenimines, see: (a) Krow, G. R. Angew. Chem., Int.
Ed. Engl. 1971, 10, 435. (b) Perst, H. Sci. Synth. 2006, 23, 781. (c) Yoo,
E. J.; Chang, S. Curr. Org. Chem. 2009, 13, 1766. (d) Lu, P.; Wang, Y.
Synlett 2010, 2010, 165. (e) Kim, S. H.; Park, H. S.; Choi, J. H.; Chang, S.
Chem. - Asian J. 2011, 6, 2618. (f) Lu, P.; Wang, Y. Chem. Soc. Rev. 2012,
41, 5687.
(2) Jochims, J. C.; Anet, F. A. L. J. Am. Chem. Soc. 1970, 92, 5524.
(3) (a) Neuman, R. C., Jr.; Sylwester, A. P. J. Org. Chem. 1983, 48, 2285.
(b) Molina, P.; Alajarin, M.; Vidal, A. J. Org. Chem. 1992, 57, 6703.
(c) Denonne, F.; Seiler, P.; Diederich, F. Helv. Chim. Acta 2003, 86,
3096. (d) Alajarin, M.; Bonillo, B.; Ortin, M.-M.; Sanchez-Andrada, P.;
Vidal, A. Org. Lett. 2006, 8, 5645. (e) Yang, Y.-Y.; Shou, W.-G.; Hong,
D.; Wang, Y.-G. J. Org. Chem. 2008, 73, 3574. (f) Zhou, X.; Zhang, Z.;
Zhao, H.; Lu, P.; Wang, Y. J. Org. Chem. 2017, 82, 3787.
(4) (a) Frøyen, P. Acta Chem. Scand. 1974, 28b, 586. (b) Capuano, L.;
Willmes, A. Liebigs Ann. Chem. 1982, 1982, 80. (c) Zhou, X.; Jiang, Z.;
Xue, L.; Lu, P.; Wang, Y. Eur. J. Org. Chem. 2015, 2015, 5789.
(5) (a) Lage, N.; Masson, S.; Thuillier, A. J. Chem. Soc., Perkin Trans. 1
1991, 2269. (b) Lage, N.; Masson, S.; Thuillier, A. J. Chem. Soc., Perkin
Trans. 1 1991, 3389.
(6) (a) Stevens, C.; French, J. C. J. Am. Chem. Soc. 1954, 76, 4398.
(b) Lambrecht, J.; Gambke, B.; Von Seyerl, J.; Huttner, G.;
Kollmannsberger-von Nell, G.; Herzberger, S.; Jochims, J. C. Chem.
(20) Zhang, Y.; Hsung, R. P.; Tracey, M. R.; Kurtz, K. C. M.; Vera, E. L.
Org. Lett. 2004, 6, 1151.
(21) For a compilation of Hammett and resonance parameters, see:
Hansch, C.; Leo, A.; Taft, R. W. Chem. Rev. 1991, 91, 165.
(22) The σ− values of 2d and 2e are identical. The additional σ
withdrawing of the OMe groups renders 2e less electron-releasing.
(23) Hiroi, K.; Sato, S. Chem. Pharm. Bull. 1985, 33, 2331.
́
(24) For reviews of kinetic isotope measurements, see: (a) Gomez-
Gallego, M.; Sierra, M. A. Chem. Rev. 2011, 111, 4857. (b) Simmons, E.
M.; Hartwig, J. F. Angew. Chem., Int. Ed. 2012, 51, 3066.
(25) The deuterium incorporation of d-1a was 75%.
(26) For full details and a fully annotated mass spectrum from this
D
Org. Lett. XXXX, XXX, XXX−XXX