Synthesis, characterization of palladium hydroxysalen complex and its application in the coupling reaction of arylboronic acids: Mizoroki–Heck type reaction and decarboxylative couplings

(Salen-OH)Pd (1, salen-OHdouble bond; length as m-dashN,N′-bis(3,5-di-hydroxysalicylidene)-ethylenediamine) was prepared by a simple one step reaction and fully characterized by 1H and 13C NMR, IR spectroscopy, and X-ray crystallography. This palladium complex showed good activities as a catalyst in the Mizoroki–Heck-type reaction and the decarboxylative coupling reaction. In the Mizoroki–Heck type reaction, arylboronic acids and alkenes were reacted at 90 °C for 3 h in the presence of 2.0 mol% of the palladium complex 1 and AgOAc to give the desired coupled product in good yields. In the decarboxylative coupling reactions, the desired coupled products were obtained in good yields when 0.5 mol% of the palladium complex was employed at room temperature.