| Popis: |
1,1-Bis(triflyl)alkadienes are easily prepared by mixing bis(triflyl)methane and α,β-unsaturated aldehydes and then used as easy-to-handle building blocks for the preparation of strongly acidic carbon acids. The reaction of these alkadienes with either NaBH4 or organocerium reagents gave the desired carbon acids through a β-selective nucleophilic addition reaction. Similar reactions of a 1,1-bis(trifyl)alkadiene with sterically bulky iPrMgBr resulted in a δ-selective alkylation instead. The present β-alkylation is the realization of the synthesis of β-branched 1,1-bis(triflyl)alkanes with an acidic CH moiety. Furthermore, when submitted to a Mukaiyama aldol reaction, such β-branched carbon acids had a higher catalyst activity than that of the corresponding nonbranched carbon acids. |
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