Supramolecular Stereocontrol of Octahedral Metal-Centered Chirality. Ligand Modulation Jonathan J. Jodry, Richard Frantz, and Je ´ro ˆ me Lacour* De ´ partement de Chimie Organique, UniVersite ´ de Gene ` Ve, quai Ernest-Ansermet 30, CH-1211 Gene ` Ve 4, Switzerland Received March 15, 2004 By associating chiral labile [FeL 3 ] 2+ complexes with TRISPHAT anions, a stereocontrol of the metal-centered chirality is feasible; the sense of the stereoselective induction and its magnitude strongly depends upon the structure of the diimine ligands (L: bpy, phen). Much progress has been made in metal-directed and metal- templated synthesis to allow chemists to prepare molecular and supramolecular complexes of original structure and geometry. 1 In many instances, the derivatives are chiral and are obtained only as racemates due to the presence in solution of an equilibrium between the enantiomers. To obtain these compounds in one predominant configuration, a possible strategy is to introduce stereogenic elements to the backbone of the ligands; 2 intramolecular discriminating interactions happen and favor one of the interconverting diastereomers. 3 If the complexes are charged, a complementary strategy to control their configuration is to consider their ion pairing with chiral counterions; 4 intermolecular diastereoselective interactions can induce a stereoselective induction (Pfeiffer effect). 5 Recently, chiral TRISPHAT anion 1 (tris(tetrachloroben- zenediolato)phosphate(v), Λ or ∆ enantiomers, Figure 1) 6 has been shown to be a valuable resolving and asymmetry- inducing reagent for cationic metalloorganic and organome- tallic complexes. 7 For instance, associated with configura- tionally labile [Fe(phen) 3 ] 2+ 2 and [Fe(4,4′-Me 2 bpy) 3 ] 2+ 6, two anions 1 control effectively the ∆ or Λ configuration of the iron(II) complexes (phen ) 1,10-phenanthroline; bpy ) 2,2′-bipyridine). 8 Diastereomeric ratios higher than 49:1 were measured in CDCl 3 in favor of the homochiral salts. 8a,c The characterization and quantification of the asymmetry induc- tion was performed by circular dichroism (CD) and by NMR spectroscopy as the anions are, in addition, good chiral shift agents. 7 This supramolecular approach to the stereocontrol of octahedral metal centers allows a simple access to both * Author to whom correspondence should be addressed. E-mail: jerome.lacour@chiorg.unige.ch. (1) Caulder, D. L.; Raymond, K. N. Acc. Chem. Res. 1999, 32, 975- 982. Collin, J. P.; Dietrich-Buchecker, C.; Gavina, P.; Jimenez-Molero, M. C.; Sauvage, J. P. Acc. Chem. Res. 2001, 34, 477-487. Fujita, M.; Umemoto, K.; Yoshizawa, M.; Fujita, N.; Kusukawa, T.; Biradha, K. Chem. Commun. 2001, 509-518. Seidel, S. R.; Stang, P. J. Acc. Chem. Res. 2002, 35, 972-983. Lehn, J.-M. Science 2002, 295, 2400- 2403. (2) Knof, U.; von Zelewsky, A. Angew. Chem., Int. Ed. 1999, 38, 303- 322. Brunner, H. Angew. Chem., Int. Ed. 1999, 38, 1194-1208. Mamula, O.; von Zelewsky, A. Coord. Chem. ReV. 2003, 242, 87- 95. Chelucci, G.; Thummel, R. P. Chem. ReV. 2002, 102, 3129-3170. (3) Mizuno, T.; Takeuchi, M.; Hamachi, I.; Nakashima, K.; Shinkai, S. Chem. Commun. 1997, 1793-1794. Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Woods, C. R.; Siegel, J. S. Eur. J. Inorg. Chem. 2001, 173-180. Telfer, S. G.; Yang, X.-J.; Williams, A. F. Dalton Trans. 2004, 699-705. (4) Macchioni, A. Eur. J. Inorg. Chem. 2003, 195-205. (5) Pfeiffer, P.; Quehl, K. Chem. Ber. 1931, 64, 2667-2671. Norden, B.; Tjerneld, F. FEBS Lett. 1976, 67, 368-370. Kirschner, S.; Ahmad, N.; Munir, C.; Pollock, R. J. Pure Appl. Chem. 1979, 51, 913-923. Green, M. M.; Khatri, C.; Peterson, N. C. J. Am. Chem. Soc. 1993, 115, 4941-4942. Owen, D. J.; VanDerveer, D.; Schuster, G. B. J. Am. Chem. Soc. 1998, 120, 1705-1717. Yeh, R. M.; Ziegler, M.; Johnson, D. W.; Terpin, A. J.; Raymond, K. N. Inorg. Chem. 2001, 40, 2216-2217. Hiraoka, S.; Harano, K.; Tanaka, T.; Shiro, M.; Shionoya, M. Angew. Chem., Int. Ed. 2003, 42, 5182-5185. (6) Lacour, J.; Ginglinger, C.; Grivet, C.; Bernardinelli, G. Angew. Chem., Int. Ed. Engl. 1997, 36, 608-609. (7) Lacour, J.; Hebbe-Viton, V. Chem. Soc. ReV. 2003, 32, 373-382. (8) (a) Lacour, J.; Jodry, J. J.; Ginglinger, C.; Torche-Haldimann, S. Angew. Chem., Int. Ed. 1998, 37, 2379-2380. (b) Monchaud, D.; Jodry, J. J.; Pomeranc, D.; Heitz, V.; Chambron, J.-C.; Sauvage, J.- P.; Lacour, J. Angew. Chem., Int. Ed. 2002, 41, 2317-2319. (c) Pe ´rollier, C.; Constant, S.; Jodry, J. J.; Bernardinelli, G.; Lacour, J. Chem. Commun. 2003, 2014-2015. Figure 1. Interconversion between Λ and ∆ enantiomers of [Fe- (diimine)3] 2+ complexes and possible stereoselective induction from enan- tiopure TRISPHAT anion 1. Inorg. Chem. 2004, 43, 3329-3331 10.1021/ic049661d CCC: $27.50 © 2004 American Chemical Society Inorganic Chemistry, Vol. 43, No. 11, 2004 3329 Published on Web 04/24/2004