ORGN 445 |
| The enimide moiety is an important substructure often encountered in biologically active compounds and synthetic drugs. Moreover, enamides and their derivatives are versatile synthetic intermediates for the preparation of chiral amines, amino acids and various heterocyclic compounds. Traditional syntheses involve rather harsh reaction conditions such as high temperatures and/or the use of strong bases. We have recently disclosed a general protocol for the catalytic addition of secondary N-nucleophiles to terminal alkynes providing a convenient synthetic entry to enamides, N-alkenyl carbamates, N-alkenyl ureas, and N-alkenyl lactams. We now report on an improved catalyst system that overcomes a key limitation of the first generation catalysts and allows the conversion of primary amides and imides. In the new catalyst system, we have combined the ruthenium catalyst with a strong Lewis acid. The reaction is highly efficient and exclusively gives the Markovnikov products in good stereoselectivities for the (E)-configured enimides.
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Modern Acetylene Chemistry
8:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Division of Organic Chemistry |
