Phenolate Sodium → Carbonate Ion

Beteiligte Stoffe

Reaktionsschritte

Alkali metal phenoxides as nucleophiles proved to be superior to the combination of phenol and amine base. Sodium phenoxide furnished the corresponding allylation product with high regio- and enantioselectivity (Table 6, entries 4-6). Reaction of sodium phenoxide with methyl carbonate 1a formed the alkylation product at room temperature in a modest 40% yield because of competing trans-esterification (entry 4), but reactions with the more hindered and less reactive (E)-cinnamyl ethyl carbonate (1b of Table 6) occurred without significant competing transesterification. This combination of phenoxide and carbonate gave the branched ether in good yields with excellent regio- and enantioselectivities after 35 h at room temperature or 17 h at 50° C. (Table 6, entries 5 and 6).

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