Notes A New Methodology for Synthesis of Aryl Bismuth Compounds: Arylation of Bismuth(III) Carboxylates by Sodium Tetraarylborate Salts Vitalie Stavila, John H. Thurston, Darío Prieto-Centurión, and Kenton H. Whitmire* Department of Chemistry, MS 60, Rice UniVersity, 6100 Main Street, Houston, Texas 77005 ReceiVed September 28, 2007 Summary: Sodium tetraarylborate salts Na[BAr 4 ] (Ar ) C 6 H 5 (Ph), C 6 H 4 -Me-4 (tolyl), C 6 H 4 -F-4) are found to be efficient arylating species for a range of bismuth(III) aromatic and aliphatic carboxylates including Bi(Hsal*) 3 (Hsal* ) 2-HO- C 6 H 4 CO 2 - (Hsal); 4-Me-2-HO-C 6 H 3 CO 2 - (Hsal 4Me ); or 3-MeO- 2-HO-C 6 H 3 CO 2 - (Hsal 3OMe )) and Bi(O 2 CR) 3 (R ) Me, CMe 3 , and CF 3 ) to produce triaryl bismuth compounds. The reactions may be carried out in ethanol, tetrahydrofuran, or acetone. The arylbismuth bis(salicylates) BiPh(Hsal) 2 and Bi(tolyl)(Hsal) 2 exhibit similar reactiVity in refluxing THF and may be used to produce mixed arylbismuthines BiPh x (tolyl) 3-x . Formation of the known arylbismuth compounds was confirmed by IR spectroscopy, X-ray crystallography, NMR spectroscopy ( 1 H, 11 B, 13 C, and 19 F), and mass spectrometry. This is a facile synthesis of both symmetrical and unsymmetrical triarylbis- muthines inVolVing the aryl group transfer from the tetraarylbo- rate ions to bismuth(III) under mild conditions. Introduction Aryl bismuth compounds have been known since the 1880s, when Michaelis reported the synthesis of triphenyl bismuth from Bi-Na alloys and bromobenzene in ethylacetate. 1,2 The chem- istry and uses of arylbismuth compounds have been recently reviewed. 3 They are employed as co-catalysts for various polymerization processes, as additives in dental and medical devices as X-ray opaque substances, and as arylating agents for a range of organic substrates. They serve as starting compounds to synthesize various classes of bismuth(III) and bismuth(V) compounds, and even though the coordinating ability of bismuth(III) is weak, some examples of their use as ligands for transition metals have been reported. Triarylbismuth(III) derivatives are usually prepared from BiCl 3 using organomag- nesium or organolithium reagents in donor solvents such as THF or diethyl ether. This methodology is well-developed, but the reactions must be run under a rigorously dry atmosphere and one must carefully control the rate of addition of the reagents and the temperature. BiCl 3 , which is hygroscopic and must be carefully purified prior to use, undergoes redistribution reactions with BiAr 3 to give mixtures of BiAr 3-x Cl x (x ) 0–3), so the stoichiometry must be precisely controlled in order to achieve good yields of pure materials. The use of tetraarylborate salts as nucleophilic arylating agents for metal ions has been reported. 4 A number of main group and transition metals undergo arylation upon treatment with tetraarylborate salts. During our investigations of hetero- metallic complexes as precursors for mixed-metal oxide materi- als, we found that salicylate-alkoxide complexes can be produced from the reaction of bismuth(III) salicylate with early transition metal alkoxides. In an attempt to introduce alkali metal cations in the system, some heterometallic Bi-Nb and Bi-Ta complexes were treated with sodium tetraphenylborate. The products contained no sodium; however, one or more salicylate ions on bismuth were replaced by phenyl groups. These results, which will be detailed elsewhere, prompted us to explore the general reactivity of tetraarylborate salts toward bismuth(III) carboxylates. Results and Discussion Symmetrical tris(aryl)bismuth compounds are prepared by the reaction of bismuth(III) salicylates with sodium tetraaryl borates (Scheme 1). The reactions proceed smoothly in good to excellent yields in THF, alcohols, or acetone. In a representative procedure, freshly prepared Bi(Hsal) 3 reacts with 3 equiv of sodium tetraphenylborate in ethanol at room temperature over a period of 16 h, during which the initial pale orange color of the reaction mixture gradually changes to pale yellow. Upon * To whom correspondence should be addressed. E-mail: whitmir@ rice.edu. Phone: 713-348-5650. Fax: 713-348-5155. (1) Michaelis, A.; Polis, A. Ber. Dtsch. Chem. Ges. 1887, 20, 55–56. (2) Michaelis, A.; Marquardt, A. Liebigs Ann. Chem. 1889, 251, 323– 335. (3) (a) Suzuki, H., Matano, Y., Eds. Organobismuth Chemistry; Elsevier: New York, 2001; 619 pp. (b) Freedman, L. D.; Doak, G. O. Chem. ReV. 1982, 82, 15–57. (4) Strauss, S. H. Chem. ReV. 1993, 93, 927–942. (5) (a) Coombs, D. L.; Aldridge, S.; Rossin, A.; Jones, C.; Willock, D. J. Organometallics 2004, 23, 2911–2926. (b) Sacconi, L.; Dapporto, P.; Stoppioni, P. Inorg. Chem. 1976, 15, 325–329. (c) Haines, R. J.; Du Preez, A. L. J. Am. Chem. Soc. 1971, 93, 2820–2821. Scheme 1. Synthetic Procedures to Triarylbismuth Com- pounds by Arylation with Sodium Tetraarylborates Organometallics 2007, 26, 6864–6866 6864 10.1021/om7009667 CCC: $37.00  2007 American Chemical Society Publication on Web 11/29/2007