An ammonia equivalent for the palladium-catalyzed amination of aryl halides and triflates

Tetrahedron Letters

Volumn 38, Issue 36, 1997, Pages 6367-6370

  Wolfe, John P ^a   Åhman, Jens ^a   Sadighi, Joseph P ^a   Singer, Robert A ^a   Buchwald, Stephen L ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AMINE; ANILINE DERIVATIVE;

AMINATION; ARTICLE; DRUG SYNTHESIS; IN VITRO STUDY; METHODOLOGY; REACTION ANALYSIS;

EID: 0030873988     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(97)01465-2     Document Type: Article

References (17)

1. (a) Wolfe, J. P.; Wagaw, S.; Buchwald, S. L. J. Am. Chem. Soc. 1996, 118, 7215.
2. (b) Driver, M. S.; Hartwig, J. F. J. Am. Chem. Soc. 1996, 118, 7217.
3. Wolfe, J. P.; Buchwald, S. L. J. Am. Chem. Soc., in press.
4. Wolfe, J. P.; Buchwald, S. L. Manuscript submitted.
5. (e) Wolfe, J. P.; Buchwald, S. L. J. Org. Chem. 1997, 62, 1264 and references cited therein.
6. (f) Louie, J.; Driver, M. S.; Hamann, B.C.; Hartwig, J. F. J. Org. Chem. 1997, 62, 1268 and references cited therein.
7. (g) Åhman, J.; Buchwald, S. L. Tetrahedron Lett. 1997, accompanying paper in this issue.
8. (a) Wessjohann, L.; McGaffin, G.; de Meijere, A. Synthesis, 1989, 359.
9. (b) Fasth, K.-J.; Antoni, G.; Långstrom, B. J. Chem. Soc., Perkin Trans. I 1988, 3081.
10. O'Donnell, M. J.; Boniece, J. M.; Earp, S. E. Tetrahedron Lett. 1978, 2641.
11. Taguchi, K.; Westheimer, F. H. J. Org. Chem. 1971, 36, 1570.
12. Representative Procedure: An oven-dried Schlenk tube was charged with Pd2(dba)3 (0.00125 mmol) and BINAP (0.00375 mmol), and purged with argon. To the flask was added 4-t-butylbromobenzene (1.00 mmol), benzophenone imine (1.20 mmol), NaOtBu (1.40 mmol) and toluene (4 mL), and the mixture was heated to 80°C with stirring until the starting material had been consumed as judged by GC analysis. The mixture was cooled to room temperature, diluted with ether (10 x volume of toluene), filtered, and concentrated. The crude product was then recrystallized from MeOH. Yellow crystals of the diphenyl ketimine adduct were isolated in 90% yield.
13. 3 to carry out the Pd-catalyzed (3 mol%) coupling of α-naphthyltriflate and benzophenone imine in 82% yield at 110°C in toluene (24 h). Utilizing DBU as a base has not been found to be general in scope.
14. 4 and concentrated in vacuo.
15. The imine adducts are stable to purification by chromatography on silica gel. As a further demonstration of the stability of the diphenyl ketimine, we have found that it was possible to carry out halogen metal exchange (n-BuLi, THF, -78°C) on the benzophenone imine protected 4-bromoaniline without substantial (<5 %) addition to the imine.
16. Reductive elimination from palladium should be more facile (electronically) for an imine than an amine.
17. Manecke, G.; Vogt, H. G. J. Solid-Phase Biochem. 1979, 4, 233.