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

One-Pot Tandem Hiyama Alkynylation/Cyclizations by Palladium(II) Acyclic Diaminocarbene (ADC) Complexes Yielding Biologically Relevant Benzofuran Scaffolds

“…Important is the comparison of the Hiyama coupling products obtained using our catalyst to those obtained by other reactions. In particular, diphenyl acetylene was obtained in a 76% yield at 2 mol % of catalyst 4 loading under our Hiyama alkynylation condition, which is slightly lower than the near-quantitative yield of 99% obtained using CuI (10 mol %), 94 of 94% obtained using a palladium hydroxysalen complex (3 mol %), 95 and of 85% obtained using a [ bromide in a 94% yield in the presence of a Cu(I) PNP pincer complex as the catalyst (5 mol %) 97 and also by Sonogashira coupling. 98,99 Likewise, for other substrates too, the decarboxylative cross-coupling reaction produced better yields than our Hiyama alkynalation reaction.…”

“…Important is the comparison of the Hiyama coupling products obtained using our catalyst to those obtained by other reactions. In particular, diphenyl acetylene was obtained in a 76% yield at 2 mol % of catalyst 4 loading under our Hiyama alkynylation condition, which is slightly lower than the near-quantitative yield of 99% obtained using CuI (10 mol %), of 94% obtained using a palladium hydroxysalen complex (3 mol %), and of 85% obtained using a [1,3-bis­(2,6- i Pr 2 C 6 H 3 )­imidazol-2-yilidene]­PdCl 2 [3-ClC 6 H 4 N] complex (5 mol %) using decarboxylative coupling between alkynyl carboxylic acid with aryl iodide/boronic acid/diazonium salts. Apart from this, diphenyl acetylene in high yield has been reported by reaction of aryl halides with alkynyl magnesium bromide in a 94% yield in the presence of a Cu­(I) PNP pincer complex as the catalyst (5 mol %) and also by Sonogashira coupling. , Likewise, for other substrates too, the decarboxylative cross-coupling reaction produced better yields than our Hiyama alkynalation reaction.…”