Communication
Keywords: heterocycles · ortho-amidation · rhodium catalysis ·
sulfoximines · thiadiazine 1-oxides
[5] For a summarizing overview on such developments, see: U. Lꢂcking,
[6] a) Y. Zhou, T. Bertolini, L. Li (Anadys Pharmaceuticals, Inc.), US
20080292588A1, 2008; b) R. W. Buckheit Jr., V. Fliakas-Boltz, W. D.
Decker, J. L. Roberson, T. L. Stup, C. A. Pyle, E. L. White, J. B. McMahon,
Buckheit Jr., V. Fliakas-Boltz, W. D. Decker, J. L. Roberson, C. A. Pyle, E. L.
White, B. J. Bowdon, J. B. McMahon, M. R. Boyd, J. P. Bader, D. G. Nickell,
(Gçdecke AG), DE 4135479A1, 1993; e) A. Hizi, R. Tal, M. Shaharabany,
M. J. Currens, M. R. Boyd, S. H. Hughes, J. B. McMahon, Antimicrob.
wan, P. W. Hairsine, D. P. Kay, P. D. Kennewell, S. S. Matharu, P. Miller, P.
31, 1098; g) H. Barth, J. Hartenstein, G. Satzinger, E. Fritschi, H. Osswald,
G. Bartoszyk (Gçdecke AG), DE 3433037A1, 1986; h) R. Wenger (Sandoz
AG), CH 599226A5, 1978; i) R. Wenger (Sandoz AG), CH 599227A5,
1978; j) R. D. Dillard, D. E. Pavey (Eli Lilly and Co.), DE 2813288A1, 1978;
k) R. D. Dillard, D. E. Pavey (Eli Lilly and Co.), US 4100280A, 1978; l) F. A.
Sowinski, B. R. Vogt (E. R. Squibb & Sons, Inc.), US 4022774A, 1977;
m) P. J. Stoss, G. Satzinger (Gçdecke AG), DE 2530792A1, 1977; n) F. A.
Sowinski, B. R. Vogt (E. R. Squibb & Sons, Inc.), DE 2455232A1, 1975;
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1975; p) E. Cohnen (Beiersdorf AG), DE 2321786A1, 1974.
ecke AG), US 5321024A, 1994; c) R. W. Buckheit, Jr., V.-F. Boltz, W. D.
Decker, J. L. Robertson, C. A. Pyle, E. L. White, B. J. Bowdon, J. B. McMa-
hon, M. R. Boyd, J. P. Bader, D. G. Nickell, H. Barth, T. K. Antonucci, Antivi-
Scheme 4. Copper-catalyzed N-alkynylation of 4aa.
In summary, we developed a new access towards thiadiazine
1-oxides with rhodium(III)-catalyzed ortho-amidations of NH-
sulfoximines as the key transformation. As the starting materi-
als are readily available commercially, a variety of products can
now be obtained in a straightforward manner, leading to core
scaffolds for potentially bioactive molecules.
Experimental Section
General procedure for the rhodium-catalyzed amidation
A
5
Schlenk tube (25 mL) was charged with sulfoximine
(0.60 mmol), aroyloxycarbamat (0.20 mmol),
6
[Cp*Rh(MeCN)3(SbF6)2] (8.3 mg, 0.010 mmol), and NaOAc (19.7 mg,
0.24 mmol). Under an argon atmosphere, dry 1,2-dichloroethane
(1.0 mL) was added to the mixture by syringe, and stirring was
continued at 1008C for 12 h. Then, the mixture was cooled to
room temperature, diluted with dichloromethane (10 mL), and fil-
tered through a Celite pad. After washing with dichloromethane
(3ꢁ20 mL), the filtrate was concentrated, and the product was pu-
rified by flash column chromatography on silica gel with a mixture
of n-pentane and acetone as the eluent affording 4 as a pure prod-
uct. For additional experimental details, see the Supporting Infor-
mation.
General procedure for the palladium-catalyzed cross-cou-
pling
A Schlenk tube (25 mL) was charged with 1-methyl-3-(methylthio)-
benzo[e][1,2,4]thiadiazine 1-oxide (10, 45.2 mg, 0.20 mmol), the
boronic acid (0.22 mmol), [Pd2dba3] (7.3 mg, 0.0080 mmol), tri(2-fur-
yl)phosphine (7.4 mg, 0.032 mmol), and CuTC (49.7 mg,
0.26 mmol). Under an argon atmosphere, dry THF (2.0 mL) was
added to the mixture by syringe. After stirring at 508C for 24 h, the
mixture was cooled to room temperature, was washed with satu-
rated NaHCO3 solution, and extracted with EtOAc (3ꢁ10 mL). The
combined organic layers were dried over MgSO4, filtered and con-
centrated. The product was purified by flash column chromatogra-
phy on silica gel with n-pentane/acetone (20:1) as eluent, affording
11 as a pure product. For additional experimental details, see the
Supporting Information.
[11] For selected reviews on CÀH aminations, see: a) K. Shin, H. Kim, S.
[12] This strategy could also be used in a late-stage functionalization ap-
proach of preformed structurally complex sulfoximines. For a recent
review on that concept, see: T. Cernak, K. Sykstra, S. Tyagarajan, P.
M. J. Ajitha, Y. Lee, J. Ryu, J. Kim, Y. Lee, Y. Jung, S. Chang, J. Am. Chem.
Acknowledgements
Y.C., W.D., and H.W. thank the China Scholarship Council for
predoctoral stipends. We also thank Dr. Shunxi Dong (RWTH
Aachen University) for helpful discussions.
Chem. Eur. J. 2016, 22, 1 – 5
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