[(4a,5,6,7,7a-h)-4-(Dimethylamino)-1H-1-pyridin-5-yl][1,2,3,4,5-h)-1,2,3,4,5-penta-phenyl-2,4-cyclopentadien-1-yl]iron

[187682-64-0]  · C45H36FeN2  · (MW 660.90)

(chiral catalyst for the kinetic resolution of secondary alcohols)

Physical Data: mp 231-234 °C.

Solubility: soluble in chlorinated and aromatic solvents; sparingly soluble in ethereal solvents and t-amyl alcohol.

Form Supplied in: purple crystals.

Handling, Storage, and Precautions: none.

Kinetic Resolution of Secondary Alcohols

This chiral derivative of DMAP serves as a nucleophilic catalyst for the acylation of secondary alcohols with anhydrides.1,2 It is very effective for the kinetic resolution of aryl alkyl carbinols, providing selectivity factors [selectivity factor = s = (rate of fast-reacting enantiomer)/(rate of slow-reacting enantiomer)] between 30 and 200 (1).3,4 Meso diols can be desymmetrized by this chiral DMAP derivative (2). The reaction is not oxygen- or moisture-sensitive, and the catalyst can be recovered essentially quantitatively at the end of the process.

The catalyst resolves many, but not all, allylic alcohols with useful levels of stereoselection (selectivity factors up to 100; 3).5

Only a small subset of propargylic alcohols are suitable substrates for this kinetic resolution, specifically, those that bear an unsaturated group on the remote position of the alkyne (4).6


1. Drauz, K.; Waldmann, H., Enzyme Catalysis in Organic Synthesis: A Comprehensive Handbook; VCH: New York, 1995.
2. (a) Vedejs, E.; MacKay, J. A., Org. Lett. 2001, 3, 535. (b) Sano, T.; Imai, K.; Ohashi, K.; Oriyama, T., Chem. Lett. 1999, 265. (c) Kawabata, T.; Nagato, M.; Takasu, K.; Fuji, K., J. Am. Chem. Soc. 1997, 119, 3169. (d) Jarvo, E. R.; Copeland, G. T.; Papaioannou, N.; Bonitatebus, P. J., Jr.; Miller, S. J., J. Am. Chem. Soc. 1999, 121 11638. (e) Iwasaki, F.; Maki, T.; Nakashima, W.; Onomura, O.; Matsumura, Y., Org. Lett. 1999, 1, 969. (f) Spivey, A. C.; Fekner, T.; Spey, S. E., J. Org. Chem. 2000, 65, 3154. (g) Naraku, G.; Shimomoto, N.; Hanamoto, T.; Inanata, J., Enantiomer 2000, 5, 135.
3. (a) Ruble, J. C.; Latham, H. A.; Fu, G. C., J. Am. Chem. Soc. 1997, 119, 1492. (b) Ruble, J. C.; Tweddell, J.; Fu, G. C., J. Org. Chem. 1998, 63, 2794.
4. Kagan, H. B.; Fiaud, J. C., Top. Stereochem. 1988, 18, 249. See also: Keith, J. M.; Larrow, J. F.; Jacobsen, E. N., Adv. Synth. Catal. 2001, 1, 5.
5. Bellemin-Laponnaz, S.; Tweddell, J.; Ruble, J. C.; Breitling, F. M.; Fu, G. C., Chem. Commun. 2000, 1009.
6. Tao, B.; Ruble, J. C.; Hoic, D. A.; Fu, G. C., J. Am. Chem. Soc. 1999, 121, 5091.

Gregory C. Fu

Massachusetts Institute of Technology, Cambridge, MA, USA



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