Asymmetric synthesis of multifunctional aryl allyl ethers by nucleophilic catalysis

Abstract

Asymmetric allylic substitution of Morita–Baylis–Hillman (MBH) carbonates with less-nucleophilic phenols mediated by nucleophilic amine catalysis was successfully developed.

Chemoselective tandem SN2′/SN2′′/inter- or intramolecular Diels–Alder reaction of γ-vinyl MBH carbonates with phenols and o-hydroxychalcones

“…Preliminary examination revealed that all nucleophiles tended to attack the acrylate moiety of 1a directly to give S N 2′ adduct 3′ (Table 1, entries 1–3), while γ-allylation product from an alternative S N 2′/S N 2′ process was not observed. Surprisingly, using phenol 2a as nucleophile 10 under high temperature conditions also furnished two cyclohexene derivatives 3a and 3a′′ (entry 4). It can be inferred that phenol 2a undergoes an S N 2′′ addition 11 to 3a′ at the distal double bond position, in which phenoxy anion also serves as a leaving group.…”