ORGN 587 |
Oxonitriles: Stereoselective alkylations of magnesiated nitriles
| Zhiyu Zhang, Fraser F. Fleming, and Omar Steward. Department of Chemistry, Duquesne University, 600 Forbes Ave, Pittsburgh, PA 15282 |
| Sequential addition of two different Grignard reagents to oxonitriles triggers a carbonyl addition followed by a chelation-controlled conjugate addition (Scheme). Alkylation of the resulting C-magnesiated nitriles with alkyl halide and sulfonate electrophiles occurs with retention of configuration whereas carbonyl electrophiles acylate with retention or inversion of configuration, depending on the carbonyl electrophile. Alkylations with allylic and benzylic electrophiles are non-selective implying a different alkylation mechanism. The presentation will explore a rationale for the unusual electrophile-dependent reactivity of these magnesiated nitriles. Synthetically the multicomponent reaction allows the assembly of diverse cyclic nitriles with the stereochemistry of the nitrile-bearing carbon being controlled through judicious choice of electrophile. 
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New Reactions, Methodology, Heterocycles, Aromatics
8:00 PM-10:00 PM, Wednesday, August 25, 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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