Grubbs’ Metathesis Catalyst - A Versatile Catalysts for Non-Metathetic Reactions

Introduction

Grubbs’ ruthenium-based catalysts (1 and 2) have demonstrated remarkable efficiency in olefin metathesis over the past ten years. [1] However, non-metathetic applications ­appeared very recently that deserve special attention and broaden the synthetic utility of Grubbs’ catalysts. [2] The complexes were shown to catalyze the Kharasch addition, the removal of allyl groups from amines, the atom-transfer radical polymerization, [3] the hydrogenation of olefins, the transfer hydrogenation of ketones, [4] the dehydro­genative oxidation of alcohols, the dehydrogenative condensation of alcohols, isomerization, hydrosilylation of alkynes, cycloaddition and the hydro-silylation of carbonyls. [5] The aim of this article is to give some examples of these advances, with special focus on practical concerns.

Catalyst 1 is prepared by treatment of phenyl diazo­methane with RuCl₂(PPh₃)₃ complex, followed by replacement of PPh₃ with PCy₃. [6] The replacement of one PCy₃ ligand by an imidazol-based N-heterocyclic carbene (NHC) from complex 1 affords catalyst 2 in quantitative yield. [7] Both catalysts are very stable to air and moisture.

References and Notes

• 1a Trnka TM. Grubbs RH. Acc. Chem. Res.  2001,  34:  18 
• 1b Fürstner A. Angew. Chem. Int. Ed.  2000,  39:  3012 
• 1c Schuster M. Blechert S. Angew. Chem. Int. Ed.  1997,  36:  2036 
• 1d Pariya C. Jayaprakash KN. Sarkar A. Coord. Chem. Rev.  1998,  168:  1 
• 1e Grubbs RH. Chang S. Tetrahedron  1998,  54:  4413 
• 1f Maishal TK. Sinha-Mahapatra DK. Paranjape K. Sarkar A. Tetrahedron Lett.  2002,  43:  2263 
• 1g Maishal TK. Sarkar A. Synlett  2002,  1925 
• 1h Maishal TK. Mondal B. Puranik VG. Wadgaonkar PP. Lahiri GK. Sarkar A. J. Organomet. Chem.  2005,  690:  1018 
• 2a Alcaide B. Almendros P. Chem. Eur. J.  2003,  9:  1258 
• 2b Trost BM. Toste D. Pinkerton AB. Chem. Rev.  2001,  101:  2067 
• 3a Bielawski CW. Louie J. Grubbs RH. J. Am. Chem. Soc.  2000,  122:  12872 
• 3b Simal F. Demonceau A. Noels AF. Angew. Chem. Int. Ed.  1999,  38:  538 
• 4 Louie J. Bielawski CW. Grubbs RH. J. Am. Chem. Soc.  2001,  123:  11312 
• 5 Maifeld SV. Miller RL. Lee D. Tetrahedron Lett.  2002,  43:  6363 
• 6 Schwab P. Grubbs RH. Ziller JW. J. Am. Chem. Soc.  1996,  118:  100 
• 7 Scholl M. Ding S. Lee WC. Grubbs RH. Org. Lett.  1999,  1:  953 
• 8 Schmidt B. Pohler M. Costisella B. J. Org. Chem.  2004,  69:  1421 
• 9 Werner H. Grünwald C. Stüer W. Wolf J. Organometallics  2003,  22:  1558 
• 10 Cadot C. Dalko PI. Cossy J. Tetrahedron Lett.  2002,  43:  1839 
• 11 Alcaide B. Almendros P. Alonso JM. Aly MF. Org. Lett.  2001,  3:  3781 
• 12 Hoye TR. Zhao H. Org. Lett.  1999,  1:  169 
• 13 Melis K. Opstal T. Verpoort F. Eur. J. Org. Chem.  2002,  3779 
• 14 Maifeld SV. Tran MN. Lee M. Tetrahedron Lett.  2005,  46:  105 
• 15 López F. Delgado A. Rodríguez JR. Castedo L. Mascareñas JL. J. Am. Chem. Soc.  2004,  126:  10262