Synthesis of 2-(Diarylmethylene)-3-benzofuranones Promoted via Palladium-Catalyzed Reactions of Aryl iodides with 3-Aryl-1-(2- tert-butyldimethyl­silyloxy)phenyl-2-propyn-1-ones

Abstract

3-Substituted-1-(2-tert-butyldimethylsilyloxy)phenyl-2-propyn-1-ones were coupled with aryl iodides by using palladium as a catalyst in ambient MeOH solution and gave 2-(diarylmethylene)-3-benzofuranones in moderate to good yields.

Key words

palladium - coupling - cyclizations

References

• 1a Westenburg HE. Lee KJ. Lee SK. Fong HHS. von Breeman RB. Pezzuto JM. Kinghorn AD. J. Nat. Prod.  2000,  63:  1696 
• 1b Budzikiewicz H. Laufenderg G. Clark C. Proksch P. Phytochemistry  1984,  23:  2625 
• 1c Bohlmann F. Grenz M. Gupta RK. Dhar AK. Ahmed M. King RB. Robinson H. Phytochemistry  1980,  19:  2391 
• 2a Lee BM. Lee SK. Kim HS. Cancer Lett.  1998,  132:  219 
• 2b Kinghorn AD. Fong HHS. Farnsworth NR. Mehta RG. Moon RC. Moriarty RM. Pezzuto JM. Curr. Org. Chem.  1998,  2:  597 
• 3a Kayser O. Waters WR. Woods KM. Upton SJ. Keithly JS. Kiderlen AF. Planta Med.  2001,  67:  722 
• 3b Sepuvelda BS. Cassels BK. Planta Med.  1999,  20:  199 
• 3c Kayser O. Kiderlen AF. Folkens U. Kolodziej H. Planta Med.  1999,  65:  316 
• 3d Kayser O. Kiderlen AF. Brun R. Planta Med.  2001,  67:  718 
• 4a Larock RC. Yum EK. Doty MJ. Sham KKC. J. Org. Chem.  1995,  60:  3270 
• 4b Arcadi A. Cacchi S. Del Rosario M. Fabrizi G. Marinelli F. J. Org. Chem.  1996,  61:  9280 
• 4c Saulinier MG. Frenneson DB. Deshpande MS. Vyas DM. Tetrahedron Lett.  1995,  36:  7841 
• 5a Bouyssi D. Gore J. Balme G. Louis D. Wallach J. Tetrahedron Lett.  1993,  34:  3129 
• 5b Cavicchioli M. Bouyssi D. Gore J. Balme G. Tetrahedron Lett.  1996,  37:  1429 
• 5c Arcadi A. Burini A. Cacchi S. Delmastro M. Marinelli F. Pietroni BR. J. Org. Chem.  1993,  57:  976 
• 6a Portscheller JC. Malinakova HC. Org. Lett.  2002,  21:  3679 
• 6b Roesch KR. Zhang H. Larock RC. J. Org. Chem.  2001,  66:  8042 
• 6c Wei LM. Lin CF. Wu MJ. Tetrahedron Lett.  2000,  41:  1215 
• 6d Bruyere D. Gaignard G. Balme G. Lancelin JM. Tetrahedron Lett.  1997,  38:  827 
• 6e Fournet G. Balme G. Van Hemebryck B. Gore J. Tetrahedron Lett.  1990,  31:  5147 

7

Treatment of 2-hydroxybenzaldehyde with TBDMSCl and imidazole gave compound 6 in 95% yield. Applying phenylacetylene with n-BuLi in THF resulted a respective lithium salt. Subsequent exposure the aldehyde 6 to the lithium salt provided the alcohol 7a in 90% yield. The α,β-unsaturated ketone 1a was obtained by oxidation of 7a with MnO₂ in 90% yield.