Novel Kumada Coupling Reaction to Access Cyclic (2-Azaallyl)stannanes. Cycloadditions of Cyclic Nonstabilized 2-Azaallyllithium Species Derived from Cyclic (2-Azaallyl)stannanes.
✍ Scribed by Douglas M. Mans; William H. Pearson
- Publisher
- John Wiley and Sons
- Year
- 2005
- Weight
- 41 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0931-7597
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✦ Synopsis
Organo-tin compounds S 4800 Novel Kumada Coupling Reaction to Access Cyclic (2-Azaallyl)stannanes. Cycloadditions of Cyclic Nonstabilized 2-Azaallyllithium Species Derived from Cyclic (2-Azaallyl)stannanes. -Stannanes (III) and (XXI) are prepared by treatment of thioether (I) with primary alkyl, aryl, and allylic Grignard compounds or alkylzinc bromide (IId) in the presence of Ni-or Pd-catalysts. Stannanes (III) are found to be viable precursors to reactive azaallyllithium species or azomethine ylides, which undergo [3 + 2] cycloaddition reactions with dipolarophiles to give the cycloadducts with high diastereoselectivity. In addition, cross-coupling of thiol (XXII) with Grignard reagents under the present conditions is an alternative to current methods for the generation of cyclic imines. -(MANS, D. M.; PEARSON*, W. H.; J. Org. Chem. 69 (2004) 19,