Isomerisation of allyl ethers to vinyl ethers catalysed by palladium on carbon

Isomerization of allyl aryl ethers to their 1-propenyl derivatives catalysed by ruthenium complexes

“…Double bond migration in allyl ether is catalysed by bases [1][2][3], metals on activated coal [4] and transition metal complexes: cobalt [5], nickel [6], palladium [7][8][9], rhodium [10,11]. There are many reports on isomerization on ruthenium complexes with carbene [12], aqua [13], Cp [14], carbonyl [15,16], hydride [17,18] ligands.…”

Synthesis of Substituted Phenols by Using the Ring‐Closing Metathesis/Isoaromatization Approach

“…When we tested basic conditions using DBU, which were reported by Kleinman and co-workers, [9d] desired phenol 4 d was obtained in moderate yield (68 %) ( Table 2, entry 1). Acidic conditions using p-toluenesulfonic acid (Table 2, entry 2) and transition-metal-catalyzed isomerization conditions using Pd/C [14] or RhCl 3 [15] ( Table 2, entries 3 and 4) also afforded 4 d in moderate yields (62-79 %). After screening numerous reaction conditions, we finally found that 4 d could be successfully obtained in high yield (92 %) using [RhClA C H T U N G T R E N N U N G (cod)] 2 (1 mol % Rh) and Cs 2 CO 3 Scheme 1.…”

In this issue

“…When we tested basic conditions using DBU, which were reported by Kleinman and co‐workers,9d desired phenol 4 d was obtained in moderate yield (68 %) (Table 2, entry 1). Acidic conditions using p ‐toluenesulfonic acid (Table 2, entry 2) and transition‐metal‐catalyzed isomerization conditions using Pd/C14 or RhCl 3 15 (Table 2, entries 3 and 4) also afforded 4 d in moderate yields (62–79 %). After screening numerous reaction conditions, we finally found that 4 d could be successfully obtained in high yield (92 %) using [RhCl(cod)] 2 (1 mol % Rh) and Cs 2 CO 3 (1 equiv) in dioxane/H 2 O (2:1) at 60 °C (Table 2, entry 5).…”