First use of a palladium complex with a thiosemicarbazone ligand as catalyst precursor for the Heck reaction

作者：Kovala Demertzi D^*; Yadav PN; Dernertzis MA; Jasiski JP; Andreadaki FJ; Kostas ID

来源：Tetrahedron Letters, 2004, 45(14): 2923-2926.

DOI：10.1016/j.tetlet.2004.02.062

• thiosemicarbazone
• O, N, S-ligand
• phosphine-free ligand
• palladium complex
• Heck reaction
• homogeneous catalysis

A novel palladium complex with salicylaldehyde N(4)-ethylthiosemicarbazone has been synthesized and according to its crystal structure the ligand is bound to the metal in an 0, N, S-terdentate coordination mode. This phosphorus-free system efficiently catalyzes the Heck reaction of aryl bromides (from electron-rich to electron-poor) with styrene under argon, with turnover numbers of up to 43,000, at 150 degreesC after 24h, and with a selectivity toward trans-stilbenes ranging from 92 to 96%. In air, for activated aryl bromides and for a palladium concentration of 1 mM, the yields are essentially the same as those obtained when the reaction was performed under argon.

• 出版日期2004-3-29