Palladium-catalysed carbomethoxyvinylation and thienylation of 5-iodo(bromo)-2,4-dimethoxypyrimidine in water

The Heck Reaction as a Sharpening Stone of Palladium Catalysis

“…Methyl acrylate reacts with 5-iodo-2,4-dimethoxypyrimidine under aqueous phase-transfer conditions at room temperature, giving high yields of product on a multigram scale (Scheme ) 100 …”

“…199,200 Methyl acrylate reacts with 5-iodo-2,4-dimethoxypyrimidine under aqueous phase-transfer conditions at room temperature, giving high yields of product on a multigram scale (Scheme 100). 201 The aqueous protocol has been applied to Heck reactions with immobilized iodoarenes used to build combinatorial chemistry libraries. 202 There is contradictory evidence on the influence of water on the reactions with immobilized reagents.…”

Mizoroki–Heck Reactions: Modern Solvent Systems and Reaction Techniques

“…Examples for catalyses in neat water without a PTC are rare. They are generally performed at atmospheric pressure at temperatures between 50 and 130 • C [138][139][140][141][142][143][144][145][146][147][148][149][150][151]. The catalyst loading is seldom below 1.0 mol% and, in terms of reactivity, aryl bromides are at least required for the coupling; no example of an aryl chloride has been reported so far.…”

Reactions in High-Temperature Aqueous Media

“…151 The aqueous Heck reaction of 5-iodo-2,4-dimethoxypyrimidine with thiophene for 24 h at 150 °C gave a 23% yield of 6-(2-thienyl)-2,4-dimethoxypyrimidine. 152 1,2-Dichlorobenzene after 6 h at 410 °C in D 2 O gives a variety of products containing oxygen. 93 1-Chlorohexane is completely dehalogenated after 30 min at 400 °C in water; product distribution is altered by interactions between the formed HCl and the walls of the metal reactor.…”

“…Recently, Heck reactions with cycloalkenes in water with sodium acetate at 260 °C for 20 min gave products in up to 54% yield . The aqueous Heck reaction of 5-iodo-2,4-dimethoxypyrimidine with thiophene for 24 h at 150 °C gave a 23% yield of 6-(2-thienyl)-2,4-dimethoxypyrimidine 104 Potential Alkene Synthons Examined in the Heck Coupling Reaction in Superheated Water 150 …”