ORGANIC
LETTERS
2002
Vol. 4, No. 13
2137-2139
Stereochemical Aspects of the
Iodine(III)-Mediated Aziridination
Reaction of Some Cyclic Allylic
Carbamates
Albert Padwa* and Thomas Stengel
Department of Chemistry, Emory UniVersity, Atlanta, Georgia 30322
Received March 29, 2002
ABSTRACT
The iodine(III)-mediated aziridination reaction of an indolyl-substituted carbamate requires a Rh(II) catalyst and proceeds by a metallonitrene
intermediate. Stepwise addition across the indole π-bond followed by Rh(II) detachment generates a metal-free zwitterion, which ultimately
leads to the observed products. In contrast, intramolecular aziridination of several cycloalkenyl carbamates does not require a Rh(II) catalyst
and occurs via an iminoiodinane intermediate.
Vicinal amino alcohols are found in a substantial number of
bioactive compounds1 and are also utilized for asymmetric
synthesis2 and as ligands for transition metal catalyzed
processes.3 This functionality not only is of importance in
the chemistry of aminosugars, carbohydrates, and nucleo-
sides4 but also has varied applications in organic synthesis.5
Considering the enormous potential of the â-amino alcohol
moiety for chemistry, it is not surprising that numerous
synthetic routes have been reported.6 Cyclic carbamates,
readily available from cyclocarbamation of allylic or homo-
allylic amines and alcohols,7 have often been used as crucial
intermediates for highly stereoselective construction of both
1,2- and 1,3-amino alcohol structures. Another useful strategy
is the ring opening of aziridines with oxygen nucleophiles.8
Although the transition metal catalyzed oxygen9 and
carbon transfer10 to olefins is a highly developed process,
significantly fewer reagents and procedures are available for
the analogous nitrogen atom transfer.11 On the basis of our
(6) Williams, D. R.; Osterhout, M. H.; Reddy, J. P. Tetrahedron Lett.
1993, 34, 3271. Barrett, A. G. M.; Seefeld, M. A. J. Chem. Soc., Chem.
Commun. 1993, 339. Jurczak, J.; Golebiowski, A. Chem. ReV. 1989, 89,
149. Reetz, M. T. Angew. Chem., Int. Ed. Engl. 1991, 30, 1531. Bergmeier,
S. C.; Stanchina, D. M. J. Org. Chem. 1997, 62, 4449. Bruncko, M.;
Schlingloff, G.; Sharpless, K. B. Angew. Chem., Int. Ed. Engl. 1997, 36,
1483. Petasis, N. A.; Zavialov, I. A. J. Am. Chem. Soc. 1998, 120, 11798.
Marshall, J. A.; Gill, K.; Seletsky, B. M. Angew. Chem., Int. Ed. 2000, 39,
953.
(7) Wang, T.; Izawa, S.; Kobayashi, S.; Ohno, M. J. Am. Chem. Soc.
1982, 104, 6465. Georges, M.; Mackay, D.; Fraser-Reid, B. J. Am. Chem.
Soc. 1982, 104, 1101. Bartlett, P. A.; Tauzella, D. J.; Barstow, J. F.
Tetrahedron Lett. 1982, 23, 619.
(8) Evans, D. A.; Faul, M. M.; Bilodeau, M. T.; Anderson, B. A.; Barnes,
D. M. J. Am. Chem. Soc. 1993, 115, 5328. Davis, F. A.; Zhou, P.; Reddy,
G. V. J. Org. Chem. 1994, 59, 3243. Pirrung, M. C.; Nunn, D. S. Bioorg.
Med. Chem. Lett. 1992, 2, 1489. Dehmlow, H.; Mulzer, J.; Seilz, C.;
Strecker, A. R.; Kohlmann, A. Tetrahedron Lett. 1992, 33, 3607. Legters,
J.; Willems, J. G. H.; Thijs, L.; Zwanenburg, B. Recl. TraV. Chim. Pays-
Bas 1992, 111, 59.
(9) Jacobsen, E. N. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.;
VCH: New York, 1993; Chapter 4.2. Brandes, B. D.; Jacobsen, E. N.
Tetrahedron Lett. 1995, 36, 5123.
(1) Babine, R. E.; Bender, S. L. Chem. ReV. 1997, 97, 1359. Faulkner,
D. J. Nat. Prod. Rep. 2000, 17, 7. Huff, J. R. J. Med. Chem. 1991, 34,
2305.
(2) Ager, D. J.; Prakash, I.; Schaad, D. R. Chem. ReV. 1996, 96, 835.
Ghosh, A. K.; Fidanze, S.; Senanayake, C. H. Synthesis 1998, 937.
(3) Noyori, R. Asymmetric Catalysis in Organic Synthesis; Wiley-
Interscience: New York, 1994. Gomez, M.; Muller, G.; Rocamora, M.
Coord. Chem. ReV. 1999, 193-195, 769. Seyden-Pene, J. Chiral Auxiliaries
and Ligands in Asymmetric Synthesis; Wiley-Interscience: New York, 1995.
(4) Danishefsky, S. J.; Bilodeau, M. T. Angew. Chem., Int. Ed. Engl.
1996, 35, 1380. Gijsen, H. J. M.; Qiao, L.; Fitz, W.; Wong, C. H. Chem.
ReV. 1996, 96, 443. Banoub, J.; Boullanger, P.; LaFont, D. Chem. ReV.
1992, 92, 1167.
(5) Du Bois, J.; Tomooka, C. S.; Hong, J.; Carreira, E. M. J. Am. Chem.
Soc. 1997, 119, 3179. Herold, P. HelV. Chim. Acta 1988, 71, 354.
10.1021/ol0259490 CCC: $22.00 © 2002 American Chemical Society
Published on Web 05/29/2002