ORGN 140 |
Sequential applications of Lewis acid-catalyzed Mukaiyama aldol reaction and intramolecular C-H insertion: Synthesis of highly substituted cyclobutanones
| Michael P. Doyle, Kousik Kundu, and Albert E. Russell. Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 |
| We have recently discovered that upon treatment of methyl 3-(tert-butyldimethylsilanyloxy)-2-diazo-3-butenoate (1) with aliphatic and aromatic aldehydes (2) in the presence of a Lewis acid catalyst (e.g. copper and lanthanide triflates) generates the corresponding Mukaiyama aldol products without any decomposition of the diazo moiety. When the Mukaiyama aldol adduct (3) was subjected to diazo decomposition with Rh2(OAc)4, C-H insertion was achieved in excellent yields to form substituted cyclobutanone (4). Similarly, we have observed that diazo silyl enol ether (1) undergoes Mannich addition with various imines (5) in presence of a catalytic amount of Lewis acid at ambient temperature in high yield. The diazo enol ether was found to survive various Lewis acids catalyzed organic transformation conditions. 
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Asymmetric Reactions and Syntheses, Metal-Mediated Reactions, Materials, Molecular Recognition
8:00 PM-10:00 PM, Sunday, August 22, 2004 Pennsylvania Convention Center -- Hall D, Poster
Division of Organic Chemistry
The 228th ACS National Meeting, in Philadelphia, PA, August 22-26, 2004
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