Vinylphosphonates in Organic Synthesis

Palladium‐ and Nickel‐Catalyzed Coupling Reactions of α‐Bromoalkenylphosphonates with Arylboronic Acids and Lithium Alkenylborates

“…We modified the conditions for coupling between HP(O)(OEt) 2 (1 equiv.) and (Z)-propenyl bromide 1a (1.2 equivs.)…”

“…[11,12] The results are presented in Table 3. Phenylation of (Z)-alkenyl bromide 5a with PhB(OH) 2 (1.2 equivs.) in a trial experiment under the conditions reported by Gueiffier [21] with Pd(PPh 3 ) 4 (5 mol %) and Na 2 CO 3 (1 equiv.)…”

“…Product 7a isolated in 93% yield was free of the stereoisomer 8a by 1 H NMR spectroscopy and TLC analysis. Other boronic acids, p-MeC 6 H 4 B(OH) 2 and p-MeOC 6 H 4 B(OH) 2 , showed similar reactivity to PhB(OH) 2 to provide 7b and 7c in good yields (entries 2 and 3). Likewise, p-(CH 2 ¼ CH)C 6 H 4 B(OH) 2 produced 7d in 81% yield (entry 4), which is a new monomer in polymer science.…”

“…[1] These alkenylphosphonic (or -ate) groups can be constructed by several reactions [2] such as metal-catalyzed coupling reactions of alkenyl halides with HP(O)(OR) 2 [3] and P(OR) 3 , [4] rhodium-catalyzed addition of HP(O)(OR) 2 to acetylenes, [5] Heck reaction of vinylphosphonates, [6] Wittig-and aldol-type reactions of aldehydes with methylphosphonates, [7] isomerization of allylphosphonates, [8] etc. [9] These reactions allow the synthesis of the b-monoalkyl-substituted alkenylphosphonates, but are hardly suitable for more substituted alkenylphosphonates, which would be intermediates for advanced complex analogues.…”

Microwave-assisted Hirao reaction: recent developments

“…aryl-and vinyl-phosphonates, phosphine oxides and related derivatives) are compounds of practical importance in industry, agriculture, and medicine as well as in everyday life [34][35][36][37][38][39]. In addition to their applications as pesticides, detergents, or anticorrosive agents, these phosphorus-containing synthetic compounds Scheme 10 Pd/C-catalyzed synthesis of aryl diphenylphosphine oxides (28) in water Scheme 11 Ligand-free synthesis of arylphosphonates/phosphine oxides (30) have received a lot of attention both in drug research and in medicinal chemistry due to their great potential in combating diseases and pathological conditions, and curing parasitic infections [40].…”