Reduction of Allylpalladium(II)chloride Dimer by Formation of Allyloxy­silanes

Abstract

The reduction of allylpalladium(II)chloride dimer (APC) to a Pd(0) species can be effected by reaction with alkali metal silanolates. The reduction is extremely rapid in the presence of chelating bisphosphine ligands and for a variety of silanolates.

Key words

palladium - silanolate - cross-coupling - reduction - mechanism

References and Notes

• 1a Smidt J. Hafner W. Angew. Chem.  1959,  71:  284 
• 1b Hüttel R. Kratzer J. Angew. Chem.  1959,  71:  456 
• 2 Tsuji J. Takahashi H. Morikawa M. Tetrahedron Lett.  1965,  49:  4387 
• 3 Trost BM. Chem. Rev.  1996,  96:  395 ; and references therein
• 4 Hayashi T. Uozumi Y. J. Am. Chem. Soc.  1991,  113:  9887 
• 5 Shirakawa E. Yoshida H. Kurahashi T. Nakao Y. Hiyama T. J. Am. Chem. Soc.  1998,  120:  2975 
• For representative examples, see:
• 6a Hiyama T. Hatanaka Y. Pure Appl. Chem.  1994,  66:  1471 
• 6b Wallow TI. Novak BM. J. Org. Chem.  1994,  59:  5034 
• 6c Feuerstein M. Doucet H. Santelli M. Tetrahedron Lett.  2004,  45:  8443 
• 7 Trzeciak AM. Ziólkowski JJ. Coord. Chem. Rev.  2005,  249:  2308 
• 8a Mason MR. Verkade JG. Organometallics  1992,  11:  2212 
• 8b Amatore C. Jutand A. Barki’ MAM. Organometallics  1992,  11:  3009 
• 8c Ozawa F. Kubo A. Hayashi T. Chem. Lett.  1992,  2177 
• 8d Amatore C. Carre E. Jutand A. Barki’ MAM. Organometallics  1995,  14:  1818 
• 8e Amatore C. Jutand A. J. Organomet. Chem.  1999,  576:  254 
• 9 Treciak AM. Ciunik Z. Ziólkowski JJ. Organometallics  2002,  21:  132 
• 10 Beletskaya IP. Cheprakov AV. Chem. Rev.  2000,  100:  3009 ; and references therein
• 11a Viciu MS. Germaneau RF. Navarro-Fernandez O. Stevens ED. Nolan SP. Organometallics  2002,  21:  5470 
• 11b Viciu MS. Navarro O. Germaneau RF. Kelly RA. Sommer W. Marion N. Stevens ED. Cavallo L. Nolan SP. Organometallics  2004,  23:  1629 
• 12 Denmark SE. Kobayashi T. J. Org. Chem.  2003,  68:  5153 
• 13 Trost BM. Fullerton TJ. J. Am. Chem. Soc.  1973,  95:  292 
• 14 Denmark SE. Sweis RF. In Metal-Catalyzed Cross-Coupling Reactions   Vol. 1:  de Meijere A. Diederich F. Wiley-VCH; Weinheim: 2004.  Chap. 4.
• 15a Denmark SE. Wehrli D. Org. Lett.  2000,  2:  565 
• 15b Denmark SE. Neuville L. Org. Lett.  2000,  2:  3221 
• 15c Denmark SE. Ober MH. Org. Lett.  2003,  5:  1357 
• 15d Denmark SE. Ober MH. Adv. Synth. Catal.  2004,  346:  1703 
• 15e Denmark SE. Yang S.-M. Tetrahedron  2004,  60:  9695 
• 15f Denmark SE. Yang S.-M. J. Am. Chem. Soc.  2004,  126:  12432 
• 16 Denmark SE. Baird JD. Chem. Eur. J.  2006,  12:  4954 
• 18 The formation of Pd(0) from this process was confirmed by the identification of dppbPd(dba) in the reduction mixture from K⁺ 1a ^-, dpppPd(allyl)Cl, and dba. In this experiment, no palladium black was observed. The ³¹P NMR spectrum (CDCl₃) of this reaction mixture showed two broad peaks at δ = 23.3 and 17.2 ppm which are in good agreement with those reported by Jutand for this compound (in THF) at δ = 21.3 and 17.5 ppm. No free dppb was observed. See: Amatore C. Broeker G. Jutand A. Khalil F. J. Am. Chem. Soc.  1997,  119:  5176 
• 19 Cantat T. Génin E. Giroud C. Meyer G. Jutand A. J. Organomet. Chem.  2003,  687:  365 
• 21a Åkermark B. Zetterberg K. Hansson S. Krakenberger B. Vitagliano A. J. Organomet. Chem.  1987,  335:  133 
• 21b Oslob JD. Åkermark B. Helquist P. Norrby P. Organometallics  1997,  16:  3015 
• 21c Kranenburg M. Kamer PCJ. van Leeuwen PWNM. Eur. J. Inorg. Chem.  1998,  25 
• 21d van Haaren RJ. Goubitz K. Fraanje J. van Strijdonck GPF. Oevering H. Coussens B. Reek JNH. Kamer PCJ. van Leeuwen PWNM. Inorg. Chem.  2001,  40:  3363 
• 23 Kurts AK. Sakembaeva SM. Beletskaya IP. Reutov OA. Zh. Org. Chim.  1974,  10:  1572 
• 24a Powell J. Shaw BL. J. Chem. Soc. A  1967,  1839 
• 24b Åkermark B. Åkermark G. Hegedus LS. Zetterberg K. J. Am. Chem. Soc.  1981,  103:  3037 
• 25a Braunstein P. Naud F. Dedieu A. Rohmer M.-M. DeCain A. Rettig SJ. Organometallics  2001,  20:  2966 
• 25b Kollmar M. Helmchen G. Organometallics  2002,  21:  4711 
• 26 However, this claim has not been established for allylpalladium complexes. See: Mann G. Hartwig JF. J. Am. Chem. Soc.  1996,  118:  13109 
• 27 Gregg BT. Cutler AR. Organometallics  1994,  13:  1039 
• 28 The procedure was modified from: Alonso E. Guijarro D. Yus M. Tetrahedron  1995,  51:  11457 

17

Denmark, S. E.; Ober, M. H., unpublished results.

20

The presence of the disiloxane was confirmed by GC-MS analysis. This peak was the major constituent in the GC chromatogram as determined by relative area percents.

22

The stability of the silanolate was tested using ¹H NMR spectroscopy. The ¹H NMR spectrum of a 0.075 M solution of K⁺ 1a ^- in CH₂Cl₂ was unchanged after standing at r.t. for 5 h.

29

Response Factor (R _f ) calculated using: R _f = (mmol of internal standard*area of x)/(mmol of x*area of internal standard).