Preparation of vinyl ethers using a Wittig approach, and their subsequent hydrogenation employing continuous-flow processing

Facile synthesis of α-alkoxymethyltriphenylphosphonium iodides: new application of PPh3/I2

“…Direct synthesis of enol ethers by a Wittig reaction with alkoxymethylphosphonium salt is though an evident concept but no systematic study is found in literature. Most often commercially available methoxymethylphosphonium chloride is used [ 63 , 64 ], whereas effect of other alkoxy groups as well as counter anions is still need to explore. For this purpose, at first ethoxymethyltriphenylphosphanium iodide 2c was reacted with benzaldehyde and its derivatives in the presence of n -BuLi, which afforded corresponding vinyl ethers 3a – d (Table 3 ) in good yield (67–71%) and selectivity (69–73% trans).…”

Recent Progress in Continuous‐Flow Hydrogenation

“…Vinyl ethers are important and versatile intermediates in chemistry and materials science. In 2016, Leadbeater and co‐workers prepared a variety of styryl methyl ethers using the Wittig reaction . Next, vinyl ethers (e.g., 21 ) were hydrogenated in a flow reactor (ThalesNano H‐Cube equipped with a 30 mm CatCart filled with 20 % Pd(OH) 2 /C), which was heated to 50 °C at a flow rate of 0.1 mL min −1 under a hydrogen pressure of 50 bar.…”

Base‐Promoted Reaction of Phenols with Spirocylic λ3‐Iodanes: Access to Both 2‐Iodovinyl Aryl Ethers and Diaryl Ethers

“…For example, some metal catalysts, such as, palladium, [5a] copper, [5b] and nickel [5c] have been used for vinylation of phenols with vinyl halide (Figure 1A, up). Other methods for the synthesis of vinyl ethers, such as, hydroalkoxylation of alkynes, [6a,b] vinyl ether exchange, [6c] isomerization of allyl ethers, [6d] and Horner‐Wittig olefination, [6e] have been fully developed.…”