Palladium-Catalyzed Esterification-Hydroarylation Reactions of 2-Alkynylbenzaldehydes with Aryl Iodides in Methanol

Abstract

The reaction of 2-alkynylbenzaldehydes with aryl iodides in the presence of Pd(PPh₃)₄ and K₂CO₃ in refluxing methanol for 24 hours gave the dehydrogenation-addition products, methyl 2-(2,2-disubstituted-vinyl)benzoates in modest yields; together with the cyclization products, 3-methoxy-1-monosubstituted-methylene-3-hydroisobenzofurans in 3-18% yields.

Key words

palladium - coupling - esterification-hydroarylation - 2-alkynylbenzaldehydes

References

• Recent reviews: see
• 1a Cacchi S. J. Organomet. Chem.  1999,  576:  42 
• 1b Zimmer R. Dinesh CU. Nandanan E. Khan FA. Chem. Rev.  2000,  100:  3067 
• 1c Bates RW. Satcharoen V. Chem. Soc. Rev.  2002,  31:  12 
• 1d Cacchi S. Fabrizi G. Goggiomani A. Heterocycles  2002,  56:  613 
• 2 Luo F.-T. Schreuder I. Wang R.-T. J. Org. Chem.  1992,  57:  2213 
• 3a Arcadi A. Cacchi S. Marinelli F. Synthesis  1986,  749 
• 3b Arcadi A. Cacchi S. Del Rosario M. Marinelli F. Fabrizi G. J. Org. Chem.  1996,  61:  9280 
• 4a Arcadi A. Cacchi S. Marinelli F. Tetrahedron Lett.  1992,  33:  3915 
• 4b Luo F.-T. Wang R.-T. Tetrahedron Lett.  1992,  33:  6835 
• 4c Saulnier MG. Frennesson DB. Deshpande MS. Vyas DM. Tetrahedron Lett.  1995,  36:  7841 
• 4d Cacchi S. Fabrizi G. Pace P. J. Org. Chem.  1998,  63:  1001 
• 5a Arcadi A. Burini A. Cacchi S. Delmastro M. Marinelli F. Pietroni BR. J. Org. Chem.  1992,  57:  976 
• 5b Bouyssi D. Gore J. Balme G. Louis D. Wallach J. Tetrahedron Lett.  1993,  34:  3129 
• 5c Cavicchioli M. Bouyssi D. Gore J. Balme G. Tetrahedron Lett.  1996,  37:  1429 
• 5d Rossi R. Bellina F. Biagetti M. Catanese A. Mannina L. Tetrahedron Lett.  2000,  41:  5281 
• 6a Fournet G. Balme G. Van Hemelryck B. Gore J. Tetrahedron Lett.  1990,  31:  5147 
• 6b Fournet G. Balme G. Gore J. Tetrahedron  1991,  47:  6293 
• 6c Bouyssi D. Gore J. Balme G. Tetrahedron Lett.  1991,  32:  6541 
• 6d Balme G. Bouyssi D. Tetrahedron  1994,  50:  403 
• 6e Bruyere D. Gaignard G. Bouyssi D. Balme G. Lancelin JM. Tetrahedron Lett.  1997,  38:  827 
• 7 Lin C.-F. Lu W.-D. Wang I.-W. Wu M.-J. Synlett  2003,  2057 
• 8 Wei L.-M. Lin C.-F. Wu M.-J. Tetrahedron Lett.  2000,  41:  1215 
• 9 Asao N. Nogami T. Takahashi K. Yamamoto Y. J. Am. Chem. Soc.  2002,  124:  764 
• 13 Wu M.-J. Wei L.-M. Lin C.-F. Leou S.-P. Wei L.-L. Tetrahedron  2001,  57:  7839 
• 14 Wei L.-L. Wei L.-M. Pan W.-B. Leou S.-P. Wu M.-J. Tetrahedron Lett.  2003,  44:  1979 
• 15 Wei L.-M. Wei L.-L. Pan W.-B. Wu M.-J. Tetrahedron Lett.  2003,  44:  595 
• 16a Meegalla SK. Taylor NJ. Rodrigo R. J. Org. Chem.  1992,  57:  2422 
• 16b Larock RC. Doty MJ. J. Org. Chem.  1993,  58:  4579 
• 16c Satoh T. Itaya T. Miura M. Nomura M. Chem. Lett.  1996,  823 
• 16d Muratake H. Nakai H. Tetrahedron Lett.  1999,  40:  2355 
• 16e Tanaka K. Fu GC. Angew. Chem. Int. Ed.  2002,  41:  1607 

10

Treatment of 2-iodobenzyl alcohol with phenylacetylene in the presence of catalytic amount of Pd(PPh₃)₄ and CuI, n-BuNH₂ as a base in Et₂O for 5 h gave compound 5a in 82% yield. The 2-alkynylbenzaldehyde 1a was obtained by oxidation of 5a with PCC in 91% yield.

11

Crystal data for 3aa: C₂₃H₂₀O₂; M = 328.39 g/mol, crystal size: 0.50 × 0.50 × 0.50 mm, monoclinic, space group P2₁/n, λ = 0.71073 Å, a = 9.7557 (6) Å, b = 11.9347 (7) Å, c = 15.7626 (9) Å, α = 90°, β = 99.370 (1)°, γ = 90°, V = 1810.77 (19) ų, Z = 4, D = 1.205 Mg/m³. µ = 0.076 mm^-1, T = 295 (2) K, θ range: 2.15-27.50°, reflections collected: 17775, independent reflections: 4167 (R_int = 0.0303), refinement method: full-matrix least-squares on F², final R values[ I> 2σ(I) ]: R1 = 0.0499, wR2 = 0.1234. Diffractometer: BRUKER SMART APEXCCD. Crystallographic data (excluding structure factors) for this structure have been deposited at the Cambridge Crystallographic Data centre as supplementary publication no. CCDC-223977, and may be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 1ED, UK [fax: [phone];
e-mail [e-mail]].

12

Crystal data for 4b: C₁₇H₁₆O₃; M = 268.30 g/mol, crystal size: 0.27 × 0.23 × 0.02 mm, orthorhombic, space group Pca2₁, λ = 0.71073 Å, a = 20.9353 (13) Å, b = 8.6773 (5) Å, c = 7.7543 (5) Å, α = 90°, β = 90°, γ = 90°, V = 1408.66 (15) ų, Z = 4, D = 1.265 Mg/m³. µ = 0.086 mm^-1, T = 295 (2) K, θ range: 1.95-27.50°, reflections collected: 13064, independent reflections: 3220 (R_int = 0.0619), refinement method: full-matrix least-squares on F², final R values[ I > 2σ(I) ]: R1 = 0.0902, wR2 = 0.1693. Diffractometer: BRUKER SMART APEXCCD. Crystallographic data (excluding structure factors) for this structure have been deposited at the Cambridge Crystallographic Data center as supplementary publication no. CCDC-231702.