Highly Substituted Imidazole Derivatives from a New Four-Component Synthesis Employing Methoxyallene
作者:Hans-Ulrich Reissig、Maciej Gwiazda
DOI:10.1055/s-2007-990933
日期:2008.3
A novel four-component reaction of alkoxyallenes with imines, iodine, and nitriles provided highly substituted imidazole derivatives in high overall yields. The simple three step protocol, exemplified by the reaction of methoxyallene ( 1) with imine 2, acetonitrile, and iodine leading to iodoethenyl imidazole 6 is presented with full experimental detail. Imidazole 6 could be further functionalized
A Four-Component Synthesis of Highly Substituted Imidazole Derivatives
作者:Hans-Ulrich Reissig、Maciej Gwiazda
DOI:10.1055/s-2006-947318
日期:2006.7
Addition of lithiated methoxyallene 1 to imines 2 provided allenyl amines 3, which upon reaction with iodine and nitriles furnished dihydroimidazole derivatives 5. Treatment of these intermediates with strong acids such as trifluoromethane sulfonic acid afforded tetrasubstituted imidazole derivatives 6 in good overall yields. Subsequent base-promoted conversion of 1-iodovinyl-substituted compounds 6 into alkynyl-substituted imidazole derivatives 7 proceeded smoothly. Products 6 and 7 are versatile intermediates for further transformations such as palladium-catalyzed coupling reactions.