Cross-Coupling of Aryl Halides and Triflates with Intramolecularly Stabilized Group 13-Metal Alkylating Reagents in the Presence of Mixed-Metal Catalysts

Abstract

In the presence of tertiary phosphines, the palladium-containing mixed-metal complexes [(CO)₄Fe(µ-PPh₂)Pd(µ-Cl)]₂ (1) and [(CO)₃Co]₂(µ-CO)Pd[µ-(Ph₂PCH₂)₂] (2) catalyze the cross-coupling of aryl triflates and halides (including chlorides) with intramolecularly stabilized dialkylaluminum, -gallium and -indium reagents 3-8. The reactions are high yielding, and homocoupling and hydrodehalogenation processes are minimal even when the alkyl moieties of the alkylating reagents contain β-hydrogen atoms. As the components of the mixed-metal complexes are either poor catalysts, or completely inactive, the high catalytic activity of 1 and 2 is attributed to synergism between the different metal nuclei of the catalysts.

Key words

aryl halides - cross-coupling - group 13-metal complexes - mixed-metal catalysts

References

• 1 Blum J. Gelman D. Baidossi W. Shakh E. Rosenfeld A. Aizenshtat Z. Wassermann BC. Frick M. Heymer B. Schutte S. Wernik S. Schumann H. J. Org. Chem.  1997,  62:  8681 
• 2 Blum J. Gelman D. Aizenshtat Z. Wernik S. Schumann H. Tetrahedron Lett.  1998,  39:  5611 
• 3 Blum J. Katz JA. Jaber N. Michman M. Schumann H. Schutte S. Kaufmann J. Wassermann BC. J. Mol. Catal. A: Chem.  2001,  165:  97 
• 4 Schumann H. Kaufmann J. Wassermann BC. Girgsdies F. Jaber N. Blum J. Z. Anorg. Allg. Chem.  2002,  628:  971 
• 5 Botella L. Nájera C. Angew. Chem., Int. Ed.  2002,  41:  179 
• 6 Blum J. Berlin O. Milstein D. Ben-David Y. Wassermann BC. Schutte S. Schumann H. Synthesis  2000,  571 
• 7 Gelman D. Höhne G. Schumann H. Blum J. Synthesis  2001,  591 
• 8 Gelman D. Dechert S. Schumann H. Blum J. Inorg. Chim. Acta  2002,  334:  149 
• 9 Benson BC. Jackson R. Joshi KK. Thompson DT. J. Chem. Soc., Chem. Commun.  1968,  1506 
• 10 Hidai M. Orisaku M. Ue M. Uchida Y. Yasufuku K. Yamazaki H. Chem. Lett.  1981,  143 
• 11 Uchida Y. Kenkyu, Hokoku-Asahi Garasu Kogyo Gijutsu Shoreikai  1982,  40:  49 ; Chem. Abstr. 1983, 99, 111360
• 12 Littke AF. Schwarz L. Fu GC. J. Am. Chem. Soc.  2002,  124:  6343 ; and references cited therein
• 13 Thompson DT. Platinum Met. Rev.  1975,  19:  88 
• 14 Bischoff S. Weigt A. Fujimoto K. Lücke B. J. Mol. Catal. A: Chem.  1995,  95:  259 
• 15 Casodo AL. Espinet P. Organometallics  1998,  17:  954 
• 16 Francis JA. McMahon CN. Bott SG. Barron AR. Organometallics  1999,  18:  4399 
• 17 Schumann H. Frick M. Heymer B. Girgsdies F. J. Organomet. Chem.  1996,  512:  117 
• 18 Maeda T. Okawara R. J. Organomet. Chem.  1972,  39:  87