No abstract

2-Aryl or 2,2-diaryl vinylphosphonates can be selectively obtained by using aryl halides or dialkylvinylphosphonate as the limiting reagent.

Commercial [PdCl 2 (NH 3 ) 2 ]w as appliedt oc atalyze the Mizoroki-Heck coupling of aryl halides with dialkyl allylphosphonates using iPr 2 NH as the base in water under aerobic conditions. The reactionw as conducted at8 08C( for aryl iodides) or 120 8C( for aryl bromides) for 36 h, giving the correspondinga ryl-substituted allylphosphonates in good to excellent yields, and both water-soluble and insoluble aryl halidesc ould be utilized in this reaction. After extracting the reaction solution with ethyl acetate, the residual aqueous solution was reused for the same reaction several times, and the true catalystwas found to be palladium nanoparticles. In addition, ao ne-pot synthesis of 1,4-diarylbuta-1,3-dienes, which combinedt his catalytic reactionw ith the Horner-Wadsworth-Emmons-Wittig reaction, was also performed. Results and DiscussionAt the outset, iodobenzene (1a)a nd diethyl allylphosphonate (2a)w eres elected as representativer eactants for optimization of the reactionc onditions (Table 1). When [PdCl 2 (NH 3 ) 2 ]a ssociated with aw ater-soluble cationic 2,2'-bipyridyl ligand [43] [a] W.

Various aryl‐substituted allylphosphonates are synthesized using commercial PdCl2(NH3)2 as catalyst under aerobic conditions.