An improved catalyst system for aromatic carbon-nitrogen bond formation: The possible involvement of bis(phosphine) palladium complexes as key intermediates

Journal of the American Chemical Society

Volumn 118, Issue 30, 1996, Pages 7215-7216

  Wolfe, John P ^a   Wagaw, Seble ^a   Buchwald, Stephen L ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ANILINE DERIVATIVE;

ARTICLE; CATALYSIS; DRUG SYNTHESIS; NUCLEAR MAGNETIC RESONANCE; REACTION ANALYSIS;

EID: 0029743317     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9608306     Document Type: Article

References (18)

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2. (b) Guram, A. S.; Buchwald, S. L. J. Am. Chem. Soc. 1994, 116, 7901-7902.
3. (a) Guram, A. S.; Rennels, R. A.; Buchwald, S. L. Angew. Chem., Int. Ed. Engl. 1995, 34, 1348-1350.
4. (b) Wolfe, J. P.; Buchwald, S. L. J. Org. Chem. 1996, 61, 1133-1135.
5. (c) Louie, J.; Hartwig, J. F. Tetrahedron Lett. 1995, 36, 3609-3612.
6. (d) Wolfe, J. P.; Buchwald, S. L. Unpublished results.
7. (a) Paul, F.; Patt, J.; Hartwig, J. F. J. Am. Chem. Soc. 1994, 116, 5969-5970.
8. (b) Paul, F.; Patt, J.; Hartwig, J. F. Organometallics 1995, 14, 3030-3039.
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10. (d) Driver, M. S.; Hartwig, J. F. J. Am. Chem. Soc. 1995, 117, 4708-4709.
11. BINAP = 2.2′-bis(diphenylphosphino)-1,1′-binaphthyl.
12. P/Pd ratio = 2/1.
13. Both racemic and nonracemic BINAP as expected give similar results in the animation reaction. The related tol-BINAP also gave satisfactory results in some systems.
14. Representative procedure: A Schlenk tube was charged with aryl halide (1.0 mmol), amine (1.1-1.2 mmol), sodium tert-butoxide (1.4 mmol). tris(dibenzylideneacetone)dipalladium(0) (0.0025 mmol. 0.5 mol % Pd), BINAP (0.0075 mmol), and toluene (2-9 mL) under argon. The tube was heated to 80 °C with stirring until the starting material had been completely consumed as judged by GC analysis. The solution was then allowed to cool to room temperature, taken up in ether (15 mL), filtered, and concentrated. The crude product was then purified further by flash chromatography on silica gel. Alternatively, the reaction could be performed without solvent. The procedure employed was similar to that described above; see supporting information for details.
15. (a) Widenhoefer, R. A.; Zhong, H. A.; Buchwald, S. L. Organometallics 1996, 15, 2745-2754.
16. (b) Widenhoefer, R. A.; Buchwald, S. L. Organometallics 1996, 15, 2755-2763.
17. Collman, J. P.; Hegedus, L. S.; Norton, J. R.; Finke, R. G. Principles and Applications of Organotransition Metal Chemistry: University Science Books: Mill Valley, CA, 1987; Chapter 5.
18. Whitesides, G. M.; Gaasch, J. F.; Stedronsky, E. R. J. Am. Chem. Soc. 1972, 94, 5258-5270.