Applications of α-Phosphonovinyl Tosylates in the Synthesis of α-Arylethenylphosphonates via Suzuki–Miyaura Cross-Coupling Reactions

Abstract

It has been demonstrated for the first time that α-phosphonovinyl tosylates could efficiently couple with a range of arylboronic acids to access α-arylethenylphosphonates. The unprecedented procedure exhibits excellent functional group tolerance, giving the terminal vinylphosphonates in good to excellent isolated yields (60-99%) under mild reaction conditions.

A Palladium‐Catalyzed Decarboxylative Heck‐Type Reaction of Disubstituted Vinylphosphonates in the Stereoselective Synthesis of Trisubstituted Vinylphosphonates

“…Typical synthetic methods include metal‐catalyzed hydrophosphorylation of alkynes; however, their regio‐ or stereoselectivity is difficult to control–especially for non‐terminal alkynes or unsymmetrical substituted ones (Scheme a) . The C–C coupling reactions may be a solution to these problems, whereas functionalized substrates such as α‐boronophosphonates, α‐stannylated vinylphosphonates, or alternatives are required (Scheme b), but these were neither easily available nor environmentally friendly. Despite these achievements, the development of more general, regio‐/stereoselective, and simple methods to harness them remains a challenging subject.…”

α‐Phosphonovinyl Arylsulfonates: An Attractive Partner for the Synthesis of α‐Substituted Vinylphosphonates through Palladium‐Catalyzed Suzuki Reactions

“…was conducted at room temperature in the presence of Cs 2 CO 3 (2.5 equiv.) in toluene 26a. Generally, the reactions of arylsulfonates with either electron‐neutral, ‐donating, or ‐withdrawing groups at the para ‐position on the phenyl ring did not significantly alter the reaction outcome (Table 2).…”

“…1‐(Diethoxyphosphoryl)vinyl 2,4,6‐Trimethylbenzenesulfonate (6g): 26a White solid, 3.04 g, 84 % yield, m.p. 54.3–57.5 °C.…”

“…Recently, as a part of our continuing interest in transition‐metal‐catalyzed cross‐coupling reactions,24,25 we conducted on the synthesis of terminal vinylphosphonates under palladium‐catalyzed Suzuki–Miyaura cross‐coupling reaction conditions 26. With α‐(pseudo)halovinylphosphonates as the electrophilic coupling partner,26a,26c a range of α‐aryl vinylphosphonates were efficiently prepared under palladium‐catalyzed Suzuki reaction conditions. From the viewpoint of step and atom economy, O ‐based electrophiles are more attractive than α‐halovinylphosphonates,27 which require at least four steps from starting materials (Scheme ).…”

Pd‐Catalyzed Synthesis of α‐Aryl Vinylphosphonates via Suzuki Arylation of α‐Phosphonovinyl Nonaflates

“…[10] Inspired by this report and our great interest in cross-coupling reactions, [11,12] we hypothesized that the use of readily available α-phosphonovinyl nonaflates 1a-1c [13] (Figure 1) as the electrophilic coupling partners would allow access to a broad range of terminal and internal α-aryl vinylphosphonates via Suzuki cross-coupling reactions. [14] Moreover, compared to the arylsulfonyl group, the strong electron-withdrawing nature of nonafluorobutanesulfonyl group would greatly facilitate the oxidative addition of a metal into the vinyl C-O bond.…”