ORGN 142 |
| Allylboronic acids are useful synthons in advanced organic synthesis involving allylation of electrophiles and transition metal catalyzed transformations. We have shown that palladium pincer-complex catalyzed boronation of vinyl cyclopropanes (3a), vinyl aziridines (3b) and allyl acetates (3c) could be accomplished using diboronic acid (2) as reagent in the presence of palladium pincer complex catalyst (1) affording allyl boronic acid (4) products. The allyl boronic acids were converted to synthetically useful and easily isolable trifluoro(allyl) borates (5) by reaction with KHF2. Even direct boronation of allyl alcohols (3d) could also be performed under mild reaction conditions. Interestingly, boronation of allyl alcohols can be achived faster than boronation of allyl acetates. A wide variety of allyl boronic acids and allyl trifluoroborates has been prepared by using these procedures. All catalytic transformations proceed with excellent regio- and stereoselectivity for various cyclic and acyclic substrates. Extending the scope of the reaction and the use of functionalized allylboronic acids as synthetic intermediates are in progress.
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Process R&D, Physical Organic Chemistry, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Organic Chemistry |
